Plasma Epinephrine Concentrations Research Articles

Effects of endurance exercise under hypoxic conditions on the gastric emptying rate and intestinal cell damage.

The present study examined the effects of gastric emptying rate and intestinal cell damage following a single session of endurance exercise under "hypoxic" or "normoxic" conditions at the same relative intensity. Eleven healthy males performed two trials on different days, consisting of a 60min run on a treadmill at 70% maximal running velocity (vMax) while inspiring hypoxic (FiO2: 14.5%; HYP) or normoxic air (FiO2: 20.9%; NOR). The average running velocity was 11.4 ± 0.7km/h in NOR and 10.8 ± 0.5km/h in HYP, respectively. Venous blood samples were collected to evaluate plasma intestinal fatty acid binding protein (I-FABP) as an indicator of exercise-induced intestinal cell damage. The gastric emptying rate was determined by the 13C-sodium acetate breath test. Running velocities at 70% vMax and arterial oxygen saturation were significantly lower under HYP than NOR (p < 0.001). Peak heart rate and rating of perceived exertion during exercise did not differ significantly between the trials. Maximum 13C excretion time (an indication of the gastric emptying rate) was significantly delayed in the HYP (NOR: 38.5 ± 5.0min, HYP: 45.5 ± 9.6min; p = 0.010). Furthermore, the score of nausea increased slightly, but increased significantly after exercise only in the HYP (p = 0.04). However, exercise-induced changes in plasma I-FABP, adrenaline, and noradrenaline concentrations did not differ significantly between the two trials. These results suggest that endurance exercise under hypoxic conditions impairs digestive function in the stomach compared to exercise under normoxic conditions performed at the same relative intensity.

D-Aspartate Stimulates Growth Hormone Secretion in Wethers.

Growth hormone (GH) is an essential factor in enhancing the productivity of animals. In ruminants, L-aspartate (L-Asp) stimulates the secretion of GH; however, the effect of D-Asp on GH remains unknown. Here, we examined the effect of D-Asp on GH secretion in wethers. Blood GH, insulin, adrenaline, noradrenaline, non-esterified fatty acid (NEFA), and glucose concentrations were evaluated in response to the intravenous infusion of a high-dose (0.1 mmol/kg/min) of D-Asp for 20min. Further, concentrations of these biomolecules were evaluated when a low-dose (0.05 mmol/kg/min) of D-Asp was continuously infused intravenously for 20min. Finally, the direct effect of D-Asp on GH secretion was determined using cultured sections of the anterior pituitary tissue from wethers. Infusion of the high-dose of D-Asp markedly increased blood GH concentrations (P < 0.05), resulting in an increase in the area under the curve (AUC). Plasma GH concentrations and AUC also increased in response to infusion of a low D-Asp dose. Infusion of a high and low D-Asp dose caused a prolonged reduction in plasma insulin concentrations, and the AUC was lower (P < 0.05). Plasma NEFA concentrations gradually increased after the end of D-Asp infusion, with a low D-Asp dose infusion resulting in significantly higher concentrations at 90min (P < 0.05). Plasma adrenaline, noradrenaline, and glucose concentrations did not show significant changes despite differences in the dose of D-Asp. Although D-Asp treatments stimulated GH secretion in the cultured sections of pituitary tissues, the effect was not significant. These results suggest that D-Asp stimulates the secretion of GH in wethers through not only a direct action on the pituitary gland but also through another pathway of GH stimulation.

Adrenaline Auto-Injectors for Preventing Fatal Anaphylaxis.

Anaphylaxis affects up to 5% of people during their lifetime. Although anaphylaxis usually resolves without long-term physical consequences, it can result in anxiety and quality of life impairment. Rarely and unpredictably, community anaphylaxis can cause rapid physiological decompensation and death. Adrenaline (epinephrine) is the cornerstone of anaphylaxis treatment, and provision of adrenaline autoinjectors (AAI) has become a standard of care for people at risk of anaphylaxis in the community. In this article, we explore the effectiveness of AAIs for preventing fatal outcomes in anaphylaxis, using information drawn from animal and human invivo studies and epidemiology. We find that data support the effectiveness of intravenous adrenaline infusions for reversing physiological features of anaphylaxis, typically at doses from 0.05 to 0.5 μg/kg/min for 1-2 h, or ~ 10 μg/kg total dose. Intramuscular injection of doses approximating 10 μg/kg in humans can result in similar peak plasma adrenaline levels to intravenous infusions, at 100-500 pg/mL. However, these levels are typically short-lived following intramuscular adrenaline, and pharmacokinetic and pharmacodynamic outcomes can be unpredictable. Epidemiological data do not support an association between increasing AAI prescriptions and reduced fatal anaphylaxis, although carriage and activation rates remain low. Taken together, these data suggest that current AAIs have little impact on rates of fatal anaphylaxis, perhaps due to a lack of sustained and sufficient plasma adrenaline concentration. Effects of AAI prescription on quality of life may be variable. There is a need to consider alternatives, which can safely deliver a sustained adrenaline infusion via an appropriate route.

Pharmacokinetic and Pharmacodynamic Profile of Epinephrine Nasal Spray Versus Intramuscular Epinephrine Autoinjector in Healthy Adults

BackgroundStandard of care for anaphylaxis treatment is intramuscular (IM) epinephrine. An epinephrine nasal spray (ENS) is under development as an alternative form of administration. ObjectiveTo compare the pharmacokinetic (PK) and pharmacodynamic (PD) profile of 13.2 mg ENS with 0.3 mg IM epinephrine auto-injector. MethodsData from 4 open-label phase 1 crossover studies conducted in healthy adults were pooled to determine the PK and PD profile of a single 13.2 mg ENS dose delivered by 2 consecutive sprays of 6.6 mg each in opposite (n=224 doses) or the same nostril (n=75 doses) compared with the 0.3 mg IM auto-injector (n=215 doses). Each participant served as their own control. Blood samples and vital signs were collected pre-dose and at multiple intervals from 0-360 minutes post-dose. ResultsENS rapidly increased the plasma epinephrine concentration, with levels that were overall greater than IM auto-injector. Median (range) time to maximum plasma epinephrine concentration with ENS opposite nostrils, ENS same nostril, and IM auto-injector was 25.1 (1.3, 362.1), 20.1 (3.0, 120.2), and 20.0 (1.0, 121.3) minutes, respectively. The area under the plasma concentration–time curve for 0-360 minutes was significantly higher with ENS than the IM auto-injector (geometric mean ratio [90% CI]=155% [140%, 172%] with ENS opposite nostrils, 159% [138%, 182%] with ENS same nostril). The PD effects on heart rate and blood pressure were similar in pattern and magnitude among all 3 treatment groups. ConclusionsENS rapidly achieved plasma epinephrine levels greater and more sustained than the IM auto-injector and with a similar PD effect.

The effect of transcutaneous electrical acupoint stimulation on postoperative awakening after general anaesthesia: a systematic review and meta-analysis.

The existing body of research concerning the impact of transcutaneous electrical acupoint stimulation (TEAS) on early postoperative recovery is marked by a lack of consensus. This meta-analysis, encompassing a systematic review of randomised controlled trials, seeks to critically assess the efficacy of TEAS in relation to awakening from general anaesthesia in the postoperative period. The inclusion criteria for this study were peer-reviewed randomised controlled trials that evaluated the influence of TEAS on the process of regaining consciousness following general anaesthesia. A comprehensive search was conducted across several reputable databases, including PubMed, Embase, the Cochrane Library, the China National Knowledge Infrastructure, the VIP Database, the SinoMed Database, and the WANFANG Medical Database. The search was not limited by date, extending from the inception of each database up to December 2023. The methodological quality and risk of bias within the included studies were appraised in accordance with the guidelines outlined in the Cochrane Handbook for Systematic Reviews of Interventions, version 5.1, and its associated tool for assessing risk of bias. The analysis encompassed 29 studies involving a total of 2,125 patients. Participants in the TEAS group demonstrated a significantly shorter duration to achieve eye-opening [mean difference (MD), -3.16 min; 95% confidence interval (CI), -3.93 to -2.39], endotracheal extubation (MD, -4.28 min; 95% CI, -4.79 to -3.76), and discharge from the post-anaesthesia care unit (MD, -8.04 min; 95% CI, -9.48 to -6.61) when compared to the control group receiving no or sham stimulation. Additionally, the TEAS group exhibited markedly reduced mean arterial blood pressure (MD, -9.00 mmHg; 95% CI, -10.69 to -7.32), heart rate (MD, -7.62 beats/min; 95% CI, -9.02 to -6.22), and plasma concentrations of epinephrine (standardised MD, -0.81; 95% CI, -1.04 to -0.58), norepinephrine (MD, -47.67 pg/ml; 95% CI, -62.88 to -32.46), and cortisol (MD, -110.92 nmol/L; 95% CI, -131.28 to -90.56) at the time of extubation. Furthermore, the incidence of adverse effects, including agitation and coughing, was considerably lower in the TEAS group relative to the control group (odds ratio, 0.30; 95% CI, 0.22-0.40). The findings of this study indicate that TEAS may hold promise in facilitating the return of consciousness, reducing the interval to awakening post-general anaesthesia, and enhancing the awakening process to be more tranquil and secure with a diminished likelihood of adverse events. However, caution must be exercised in interpreting these results due to the notable publication and geographical biases present among the studies under review. There is an imperative for further high-quality, low-bias research to substantiate these observations. The review protocol was registered with the PROSPERO International Prospective Register of Systematic Reviews (CRD42022382017).

Changes in blood catecholamines during induction of general anesthesia in patients with post-induction hypotension undergoing laparoscopic cholecystectomy: A single-center prospective cohort study.

Post-induction hypotension (PIH) often occurs during general anesthesia induction. This study aimed to investigate blood catecholamine levels during induction of general anesthesia in patients with PIH undergoing laparoscopic cholecystectomy. This prospective study included 557 adult patients who underwent laparoscopic cholecystectomy under general anesthesia. PIH was defined as a greater than 20% decrease in systolic blood pressure from the pre-induction value, a systolic arterial pressure of less than 90 mmHg, or both. Plasma concentrations of epinephrine and norepinephrine during the induction of general anesthesia were determined using enzyme-linked immunosorbent assay. Multivariate logistic regression analysis evaluated the association between the clinical factors and PIH. Of the 557 patients, 390 had PIH, and the remaining 167 were allocated to the non-PIH group. Changes in blood adrenaline, noradrenaline levels, or both were more pronounced in the PIH than in the non-PIH group (p<0.05). Age, body mass index, a history of hypertension, preoperative systolic blood pressure, and propofol or sufentanil dose were independent predictors of PIH. The changes of blood catecholamines in patients with more stable hemodynamics during the induction of general anesthesia are smaller than that in patients with post-induction hypotension. ChiCTR2200055549, 12/01/2022.

Plasma epinephrine and norepinephrine responses to extreme heat exposures in young and older adults.

Hyperthermia is known as a hyperadrenergic state, yet there is a lack of data on the sympathetic responses to ambient heat stress in humans. Therefore, we investigated the plasma epinephrine and norepinephrine concentrations of healthy young and older adults exposed to 3 h of very hot and dry, as well as hot and humid, heat, both with accompanying activities of daily living. We hypothesized that older adults, compared with young adults, would have augmented increases in epinephrine and norepinephrine concentrations secondary to increased thermal strain. Young (n = 20) and older (n = 18) participants underwent two 3-h heat exposures on different days: very hot and dry [47°C and 15% relative humidity (RH)] and hot and humid (41°C and 40% RH). To mimic heat generation comparable to activities of daily living, participants performed seven 5-min bouts of light cycling (approximately 3 METS) dispersed throughout the heat exposure. We measured plasma concentrations of epinephrine and norepinephrine at baseline, end, and 2-h postheat exposure. There was a group-wide increase in epinephrine from baseline to the end of the heat exposure (Δ19 ± 27 pg/mL; P < 0.001) in the hot and humid condition, but not in the very hot and dry condition (Δ6 ± 19 pg/mL; P = 0.10). There were group-wide decreases in norepinephrine concentrations from baseline to the end of the heat exposure in both the very hot and dry (Δ-131 ± 169 pg/mL; P < 0.001) and the hot and humid (Δ-138 ± 157 pg/mL; P < 0.001) conditions, with both returning to near baseline at 2-h postexposure. These data suggest that ambient heating with accompanying bouts of light intermittent exercise may lead to decreases in circulating concentrations of norepinephrine.NEW & NOTEWORTHY Herein we present plasma epinephrine and norepinephrine concentrations to 3 h of very hot and dry, as well as hot and humid, heat exposures with accompanying activities of daily living in young and older participants. We found 1) increased plasma concentrations of epinephrine in young and older adults following the hot and humid, but not the very hot and dry exposures and 2) decreased concentrations of norepinephrine in both groups following exposure to both conditions.

Randomized trial of pharmacokinetic and pharmacodynamic effects of 13.2 mg intranasal epinephrine treatment in congestion

BackgroundNasal congestion could affect the absorption of an epinephrine nasal spray (ENS). ObjectiveTo compare the pharmacokinetics of 13.2 mg ENS with nasal congestion vs without congestion and vs intramuscular (IM) treatments. MethodsThis phase I, open-label, 4-period randomized crossover study enrolled 51 healthy adults with seasonal allergies into cohorts that received a single dose of 13.2 mg ENS (NDS1C; Bryn Pharma, Lebanon, New Jersey) administered as 2 consecutive sprays in either opposite nostrils (cohort 1) or the same nostril (cohort 2). Both cohorts received 13.2 mg ENS with and without nasal allergen challenge (NAC), 0.3 mg IM epinephrine by autoinjector, and 0.5 mg IM epinephrine by manual syringe (MS). ResultsThe ENS after NAC resulted in higher extent and peak exposures and more rapid time to maximum plasma concentration vs ENS without NAC and IM treatments. In cohort 1, the maximum observed baseline-adjusted epinephrine plasma concentration (pg/mL) of ENS with NAC, IM autoinjector, IM MS, or ENS without NAC was 458.0, 279.0, 364.2, and 270.1, respectively, and in cohort 2 was 436.3, 228.2, 322.3, and 250.8, respectively. The maximum observed baseline-adjusted epinephrine plasma concentration geometric mean ratio (90% CI) for ENS with NAC vs without NAC in cohort 1 was 170% (123%-234%), and in cohort 2 was 174% (115%-263%). In cohort 1, the time to maximum plasma concentration was 15, 21, 45, and 25 minutes, respectively, and in cohort 2 was 18, 20, 45, and 20 minutes, respectively (P < .01 for ENS with NAC vs IM MS). The postdose mean heart rate and blood pressure remained stable and relatively similar to predose values regardless of plasma epinephrine concentration. Mild nausea and headache were the most common adverse events with ENS. ConclusionThe 13.2 mg ENS with congestion exhibited enhanced absorption vs IM treatments and ENS without congestion and seemed to be well tolerated. There was no clinically impactful relationship between pharmacodynamic effects and plasma epinephrine concentration.

Behavioral and physiological responses of horses to ground-based adaptive horsemanship lessons for veterans with post-traumatic stress disorder (PTSD)

Little literature exists on horses in adaptive horsemanship (AH) despite concerns about their well-being. The study objective was to evaluate behavioral and physiological responses of horses to ground-based AH lessons for veterans with post-traumatic stress disorder (PTSD). Lessons were expected to alter horses’ hormone concentrations, behavior, and muscle activity. Geldings were assigned to AH (n=6; 20.3 ± 1.9 yrs., mean ± SE) or control (CON; stall in arena, n=6; 13.8 ± 1.7 yrs.) conditions for 8-week sessions based on current occupation (AH = equine-assisted services; CON = recreational riding). Plasma cortisol, epinephrine, norepinephrine, and oxytocin concentrations from samples at 0 (start of lesson), 3, 5, 25, and 30 (end) min were determined using assays validated in horses. Surface electromyography (sEMG) (masseter and brachiocephalic; Noraxon, Scottsdale, AZ, USA) and video were recorded continuously. Average rectified values (ARV) and median frequency (MF) were calculated (100 ms) after sEMG data were normalized, rectified, and filtered. The number, number of unique, and duration of stress related behaviors (ethogram) were recorded by three trained (ĸ ≥ 0.7) observers. Data were analyzed with repeated measures ANOVAs (significance P ≤ 0.05) with fixed effects of treatment, time point, week, and their interactions as appropriate and random effect of horse. CON horses had elevated cortisol concentrations (P = 0.0023) at 25 and 30 min. AH horses displayed fewer (P ≤ 0.0491) stress related and unique behaviors. CON horses were described as more (P < 0.0001) anxious, nervous, and stressed than AH horses (calm, comfortable, patient, and relaxed) in qualitative behavior analysis (22 observers). AH horses were less stressed than CON horses.

Fasting for 48h induced similar glucose intolerance in both sexes despite greater perceived stress and decreased estradiol levels in females.

The purpose of this study was to compare the effects of fasting for 48 h on the evoked insulin and glucose responses in males and females, and to explore factors such as stress and estrogen levels that might influence these responses. Healthy, nonobese male (n = 14) and female (n = 14) subjects underwent 48-h fasting trial. Changes in glucose tolerance and insulin levels in response to the oral glucose tolerance test, subjectively perceived stress and catecholamine concentrations were measured in all participants. Estrogen levels were also measured in the female participants during the 48-h fast. Glucose area under the curve (AUC) values increased similarly in both sexes after 48-h fasting (P < 0.05), but females displayed a greater rise in insulin AUC values than males (P < 0.05). Fasting increased plasma epinephrine concentrations in both sexes (P < 0.05), whereas plasma norepinephrine concentrations and subjective stress increased only in females (P < 0.05). Plasma 17-β-estradiol concentrations in females decreased after fasting (P < 0.05). Fasting for 48h induced a similar glucose intolerance in females and males, despite decreased 17-β-estradiol levels and greater psychological and physiological stress in females. These differences represent a plausible explanation for the gender-based differences observed in insulin responses. Retrospectively registered on ClinicalTrials.gov(NCT05545943) in September 19, 2022.

Pharmacokinetics of epinephrine during cardiac arrest: A pilot study

Aim of the studyEpinephrine has been recommended for several decades for the treatment of cardiac arrest. However, although this potent medicament has a documented impact on the return of spontaneous circulation, it does not improve long-term survival. Decreased cerebral blood flow, one of the side effects of epinephrine, indicates that the use of this drug is a two-edged sword. Despite clinical recommendations, no study has investigated epinephrine pharmacokinetics in a setting of cardiac arrest. Therefore, in a pilot setting, we measured the plasma concentrations of epinephrine following a single administration. MethodsNine patients with cardiac arrest were included in our study. A single dose of 1 mg epinephrine was administered into a peripheral vein. Simultaneously, blood samples were withdrawn every minute from the jugular vein to determine the plasma concentration. A mixed effects model was used to estimate the T1/2 following the peak concentration. ResultsOne patient did not achieve a peak concentration during observation and was hence excluded. The remaining eight patients had 26 measurements suitable for modelling. In a stable model, the decline is estimated to be −0.259 [95 % CI (-0.361, −0.157) (p < 0.001)]. This implies a half-time for epinephrine of 2.6 (1.9, 4.4) minutes. ConclusionOur study indicates that elimination of epinephrine during cardiac arrest is prolonged and that repeated doses of epinephrine may lead to increased plasma levels. Further and larger studies are warranted to determine the optimal plasma concentration during resuscitation.Clinical trial registration: NCT03036202.Institutional protocol number: 2016-00189.

ВЗАИМОСВЯЗЬ ПОКАЗАТЕЛЕЙ НАПРЯЖЕННОСТИ СИМПАТОАДРЕНАЛОВОЙ СИСТЕМЫ У ПАЦИЕНТОВ С ФИБРИЛЛЯЦИЕЙ ПРЕДСЕРДИЙ ДО И ПОСЛЕ ХИРУРГИЧЕСКОГО ЛЕЧЕНИЯ

Introduction. It is known that cardiovascular diseases, including cardiac arrhythmias, are accompanied by increased activation of the sympathetic-adrenal system (SAS). Hyperactivation of the SAS causes an increase in the level of circulating catecholamines - adrenaline and norepinephrine, resulting in desensitization of β-adrenergic receptors (β-AR), aggravation of myocardial contractile dysfunction and the development of arrhythmia. Indicators of SAS tension are β-adrenergic reactivity of erythrocyte membranes (β-ARM) and the level of circulating catecholamines. One of the most common arrhythmias is atrial fibrillation (AF), which leads to a decrease in the quality of life, disability and high mortality. Therefore, among patients with AF, it is important to study the functional viability of β-AR in different periods of the disease. Purpose: to evaluate β-ARM and the level of adrenaline, norepinephrine in patients with AF before and after surgical treatment. Materials and methods. The sample included 47 patients - 31 men and 16 women, the age in the sample was 51 (26; 77) years. All patients were diagnosed with AF based on ECG and 24-hour monitoring. Among the entire sample, 59.6% of patients had paroxysmal, 25.5% persistent, 14.9% long-term persistent forms of AF. All patients underwent surgical treatment of AF using radiofrequency or cryoablation. β-ARM was determined by the method of assessing changes in erythrocyte osmotic resistance as a result of blockade of β-AR in vitro with a selective β-adrenergic blocker (Β-ARM, AGAT, Russia). Plasma epinephrine and norepinephrine concentrations were determined by enzyme-linked immunosorbent assay using Adrenalin ELISA and Noradrenalin ELISA kits (Tecan IBL International, Germany). The parameters were studied in all patients before treatment, in 44 patients after 3 days, in 18 patients after 3 months and in 9 patients after 12 months after ablation. The significance of changes in β-ARM and catecholamine levels before and after ablation was assessed using the Wilcoxon test. The strength of the linear relationship between quantitative indicators was assessed using the Spearman rank correlation coefficient. Results. In the study sample, there were no statistically significant changes in β-ARM and adrenaline levels before and at different times after ablation. Thus, the level of β-ARM before surgery was 18.2 (12.6; 25.4), after 3 days - 22.3 (14.4; 26.6), after 3 months - 20.3 (9.3 ; 29.3), and 12 months after the operation - 27.7 (16.8; 36.7). The level of adrenaline before surgery, 3 days, 3 months and 12 months after surgery was 4.4 (3.7; 6.9), 4.7 (3.0; 6.4), 4.6 (2 .5; 6.6), 5.6 (9.1; 8.8). However, an increase in the level of norepinephrine was found 12 months after ablation compared with the values before treatment and 3 days after treatment by 1.7 and 1.8 times, respectively (p = 0.028). The level of norepinephrine before surgery, 3 days, 3 months and 12 months after surgery was 40.9 (18.7; 56.6), 38.6 (14.8; 49.6), 46.7 (25 .6; 57.3), 69.3 (65.1; 80.1). Before surgery, β-ARM and norepinephrine levels were linearly correlated (r = 0.335, p = 0.037), but after treatment, the linear correlation disappeared. At 3 and 12 months after ablation, there was a strong linear correlation between adrenaline and norepinephrine levels (r = 0.611, p = 0.012; r = 0.786, p = 0.036, respectively). Conclusion. In the sample of patients with AF, β-ARM and norepinephrine levels were linearly correlated before treatment, but after ablation, the correlation disappeared. At the same time, the values of β-ARM do not change statistically significantly, and the level of norepinephrine increases during a 12-month follow-up. Thus, 12 months after treatment in patients with AF, the activity of the CAS increases, but the functional viability of beta-AR does not change significantly.

Carbohydrate, but not fat, oxidation is reduced during moderate-intensity exercise performed in 33 vs. 18°C at matched heart rates.

Exposure to environmental heat stress increases carbohydrate oxidation and extracellular heat shock protein 70 (HSP70) concentrations during endurance exercise at matched absolute, external work rates. However, a reduction in absolute work rate typically occurs when unacclimated enduranceathletes train and/or compete in hot environments. We sought to determine the effect of environmental heat stress on carbohydrate oxidation rates and plasma HSP70 expression during exercise at matched heart rates (HR). Ten endurance-trained, male cyclists performed two experimental trials in an acute, randomised, counterbalanced cross-over design. Each trial involved a 90-min bout of cycling exercise at 95% of the HR associated with the first ventilatory threshold in either 18 (TEMP) or 33°C (HEAT), with ~ 60% relative humidity. Mean power output (17 ± 11%, P < 0.001) and whole-body energy expenditure (14 ± 8%, P < 0.001) were significantly lower in HEAT. Whole-body carbohydrate oxidation rates were significantly lower in HEAT (19 ± 11%, P = 0.002), while fat oxidation rates were not different between-trials. The heat stress-induced reduction in carbohydrate oxidation was associated with the observed reduction in power output (r = 0.64, 95% CI, 0.01, 0.91, P = 0.05) and augmented sweat rates (r = 0.85, 95% CI, 0.49, 0.96, P = 0.002). Plasma HSP70 and adrenaline concentrations were not increased with exercise in either environment. These data contribute to our understanding of how moderate environmental heat stress is likely to influence substrate oxidation and plasma HSP70 expression in an ecologically-valid model of endurance exercise.

The impact of chronic stress on intracellular redox balance: A systems level analysis.

Chronic psychosocial stress is implicated in the onset and progression of noncommunicable diseases, and mechanisms underlying this relationship include alterations to the intracellular redox state. However, such changes are often investigated in isolation, with few studies adopting a system level approach. Here, male Wistar rats were exposed to 9.5 weeks of chronic unpredictable mild stress and redox status assays were subsequently performed on cardiac, hepatic, and brain tissues versus matched controls. The stressed rats displayed an anxious phenotype, with lowered plasma corticosterone levels (p= 0.04 vs. Controls) and higher plasma epinephrine concentrations (p= 0.03 vs. Controls). Our findings showed organ-specific redox profiles, with stressed rats displaying increased myocardial lipid peroxidation (p= 0.04 vs. Controls) in the presence of elevated nonenzymatic antioxidant capacity (p= 0.04 vs. Controls). Conversely, hepatic tissues of stressed rats exhibited lowered nonenzymatic antioxidant capacity (p< 0.001 vs. Controls) together with increased superoxide dismutase (SOD) activity (p= 0.05 vs. Controls). The brain displayed region-specific antioxidant perturbations, with increased SOD activity (p= 0.01 vs. Controls) in the prefrontal cortex of the stressed rats. These findings reveal distinct stress-related organ-specific vulnerability to redox perturbations and may provide novel insights into putative therapeutic targets.

Compound lidocaine/prilocaine cream combined with tetracaine prevents cough caused by extubation after general anaesthesia: a randomised controlled trial

BackgroundCoughing caused by tracheal extubation is common following general anaesthesia. Heavy aerosol production by coughing during recovery from general anaesthesia in patients with respiratory infections (especially COVID-19) may be one of the highest risk factors for infection in healthcare workers. The application of local anaesthetics to the endotracheal tube is an effective method to reduce coughing. The most commonly used anaesthetics are compound lidocaine/prilocaine cream and tetracaine spray. However, coughing still occurs when the two anaesthetics are used alone. We speculated that the application of compound lidocaine/prilocaine combined with tetracaine spray would better prevent coughing caused by tracheal extubation.MethodsPatients scheduled for laparoscopic cholecystectomy or cholecystectomy combined with common bile duct exploration under general anaesthesia were randomly assigned to Group C (saline spray), Group L (2 g compound lidocaine/prilocaine cream contains 5 mg of lidocaine and 5 mg prilocaine)), Group T (tetracaine) and Group F (compound lidocaine/prilocaine cream combined with tetracaine). The incidence of coughing, the endotracheal tube tolerance assessment, the incidence of agitation, the active extubation rate, the incidence of postoperative pharyngeal pain and the incidence of postoperative cough were recorded and analysed. Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), and the plasma concentrations of epinephrine and norepinephrine were measured immediately before extubation and 1 min after extubation.ResultsA total of 211 patients were randomly assigned to Group C (53 cases), Group L (52 cases), Group T (52 cases) and Group F (54 cases). The primary result is assessment of the incidence of cough. The patients emerged from general anaesthesia, 96% of Group C had cough, which was significantly reduced in Group L (61.5%, P < 0.001), Group T (75%, P < 0.05) and Group F (22.2%, P < 0.001). Group F had a significantly reduced incidence of cough compared to Group L and Group T (P < 0.05 or P < 0.01, respectively). The secondary results were assessed. The endotracheal tube tolerance score in Group C ((1, 3) 4, P < 0.001) was higher than Group L ((0, 1) 2), Group T ((0, 1.25) 3) and Group F ((0, 0) 1). Group F had a significantly lower score than Group L and Group T (P < 0.05, P < 0.01, respectively). The incidence of agitation and the active extubation rate were also higher in Group C (96.2% and 71.7%, respectively, P < 0.001) than Group L (48.1% and 15.4%, respectively), Group T (61.5% and 26.9%, respectively) and Group F (17.3% and 7.7%, respectively). Blood pressure, HR and plasma concentrations of epinephrine and norepinephrine were significantly higher in Group C than in all other groups at the time of extubation and 1 min after extubation (P < 0.001). Group F exhibited significantly reduced blood pressure, heart rate and plasma concentrations of epinephrine and norepinephrine compared to Group L and Group T (P < 0.05, P < 0.01 or P < 0.001, respectively). The incidence of postoperative pharyngeal pain and the incidence of postoperative cough were not significantly different among the groups.ConclusionsCompound lidocaine/prilocaine cream combined with tetracaine may be a more effective approach for preventing coughing and stabilising circulation during extubation following general anaesthesia. This may play an important role in preventing medical staff from contracting respiratory infectious diseases.Trial registrationChinese Clinical Trial Registry: ChiCTR2200058429 (registration date: 09–04-2022) “retrospectively registered”.

Adrenomedullary responses to non-invasive cortical stimulation in humans

Abstract Introduction: The discovery of cortical adrenomedullary projections in cebus monkeys suggests that similar pathways exist in humans. Notably, the major corticoadrenomedullary projection regions have human equivalents that can be stimulated non-invasively with repetitive transcranial magnetic stimulation (rTMS). If rTMS can be used to selectively modulate adrenomedullary activity, there may be significant therapeutic benefits for stress-, affective-, or neuroimmune-related disorders. Purpose: To assess resting and stress-induced adrenomedullary neuroendocrine responses to continuous (cTBS) and intermittent (iTBS) theta burst TMS in humans. Methods: 39 healthy young adults (14W) were randomly assigned to three counterbalanced sessions of iTBS (n=19) or cTBS (n=20). Stimulation was applied to motor cortical areas that contain the majority of adrenomedullary projections in non-human primates (primary motor cortex trunk region (M1TRUNK) and presupplementary motor area (preSMA)). The M1 leg region (M1LEG) was used as a spatial control. Stimulation locations were determined based on TMS-evoked electromyographic responses in the rectus abdominus (M1TRUNK) and vastus lateralis (M1LEG) or using a combination of fMRI activity and metanalytical structural coordinates (preSMA). All TMS procedures were performed with a 96mm curved double coil and stereotactic navigation. TBS was applied as 600 biphasic TMS pulses at 80% AMT. Corticoadrenomedullary activity and corticospinal excitability (CSE) were assayed before and after TBS, immediately after maximal exercise, and 60min and 90min after TBS based on plasma epinephrine concentrations and median MEP AUC, respectively. Initial analysis of adrenomedullary responses to rTMS were made with a 2 (protocol) x 3 (visit) x 5 (time-point) mixed methods ANOVA. Results and Conclusions: As expected, exercise resulted in a large epinephrine increase (p<0.0001, 8-fold) overall. Ongoing analysis indicates that target-specific changes in adrenomedullary activity are likely, and similar to CSE, may often be paradoxical. Our preliminary results also suggest that adrenomedullary responses to subthreshold rTMS are principally stress inducible. Research Category and Technology and Methods Translational Research: 10. Transcranial Magnetic Stimulation (TMS) Keywords: Adrenal Medulla, Cortex, Sympathetic Nervous System, Non-Invasive Brain Stimulation

RNA-Seq exploration of the influence of stress on meat quality in Spanish goats

Studies exploring the transcriptome of stress and its effects on meat quality are very limited, particularly in goats. Fifty-four male Spanish goats (8-mo old; BW = 29.7 ± 2.03 kg) were randomly subjected to one of three treatments (TRT; n = 18 goats/treatment): (1) transported for 180 min, (2) transported for 30 min, or (3) held in pens (control) to analyze the transcriptome of stress and meat quality in goats using RNA-seq technology. Blood samples were collected before and after treatment, and meat samples were collected after humane slaughter for stress hormone, meat quality (Longissimus dorsi), and transcriptomic analysis. Plasma epinephrine concentrations were higher (P < 0.01) in 180 min and 30 min groups compared to the control group; however, norepinephrine concentrations were not affected by the treatment. Muscle glycogen concentrations (15 min postmortem) were lower (P < 0.01) in both 30 min and 180 min groups compared to the control group. Calpastatin levels were higher (P < 0.01) in 180 min and 30 min groups than the control group. Warner–Bratzler shear force values of loin chops were the highest in the 180 min group (4 ± 0.15, kg), lowest in the control group (3.51 ± 0.10, kg), and intermediate in the 30 min group (3.78 ± 0.09, kg; P < 0.01) both at day 1 and day 6 aging time. Additionally, desmin levels of day 6 samples were lowest in the control group, highest in 180 min group, and intermediate in 30 min group (P < 0.05). RNA-seq results showed that a total of 10,633 genes were differentially expressed (5194 up regulated; 5439 down regulated) among all comparisons (blood and day 1 and day 6 muscle samples). Among these differentially expressed genes (DEGs), KLF9, AMPK, FOXO3, PTX3, GADD45, PTPN1, CASP7, MAPK4, HSPA12A, and JAK-STAT were probably associated with the effects of stress on skeletal muscle proteins and involved in biological process such as cellular response to corticosteroid stimulus, endoplasmic reticulum stress, insulin resistance, DNA repair, apoptosis, MAPK cascade and regulation of proteolysis. The KEGG analysis revealed that AMPK and JAK-SAT signaling pathways and autophagy were among the top 20 enriched pathways in our treatment comparisons. The results provide an understanding of the genes and pathways involved in stress responses and related changes in postmortem muscle metabolism and meat quality characteristics in goats.

A randomized clinical trial on effects of alfaxalone combined with medetomidine and midazolam in preventing stress-related neurohormonal and metabolic responses of isoflurane-anesthetized cats undergoing surgery.

To evaluate the effects of IM and IV administration of alfaxalone alone and in combination with medetomidine, midazolam, or both on key stress-related neurohormonal and metabolic changes in isoflurane-anesthetized cats undergoing ovariohysterectomy or castration. 72 client-owned mixed-breed cats undergoing ovariohysterectomy or castration between October 4, 2018, and January 10, 2020. For each type of surgery, cats were assigned to 1 of 6 premedication protocols groups, with 6 cats/group: physiologic saline (0.9% NaCl) solution (0.5 mL, IM) and alfaxalone (5 mg/kg, IV); physiologic saline solution (0.5 mL, IM) and alfaxalone (5 mg/kg, IM); medetomidine (50 μg/kg, IM) and alfaxalone (5 mg/kg, IV); medetomidine (50 μg/kg, IM) and alfaxalone (5 mg/kg, IM); midazolam (0.5 mg/kg, IM), medetomidine (50 μg/kg, IM), and alfaxalone (5 mg/kg, IV); or midazolam (0.5 mg/kg, IM), medetomidine (50 μg/kg, IM), and alfaxalone (5 mg/kg, IM). Venous blood was taken before pretreatment, pre- and postoperatively during anesthesia with isoflurane and oxygen, and during early and complete recovery. Compared with baseline concentrations, plasma adrenaline and noradrenaline concentrations decreased during anesthesia in cats premedicated with alfaxalone alone and in combination with medetomidine. The combination of medetomidine, midazolam, and alfaxalone prevented an excessive increase in catecholamines during anesthesia and surgery in cats. Postoperative plasma cortisol concentration after ovariohysterectomy was lower for cats premedicated with the combination of medetomidine and alfaxalone or the combination of medetomidine, midazolam, and alfaxalone, compared with cats premedicated with alfaxalone alone. Cats treated with combinations that included medetomidine and midazolam had hyperglycemia during anesthesia. Cats treated with medetomidine or medetomidine and midazolam in combination with alfaxalone, compared with alfaxalone alone, had lower concentrations of nonesterified fatty acids during anesthesia. Behavioral recovery scores were lower (better) for cats that received medetomidine in addition to alfaxalone, compared with alfaxalone alone. Results indicated that pretreatments with medetomidine and alfaxalone or with medetomidine, midazolam, and alfaxalone were useful for preventing stress-related hormonal and metabolic responses, other than hyperglycemia, during isoflurane anesthesia and surgery in cats.

α-Adrenergic blockade prevented environmental temperature reduction-induced transient portal pressure surge in cirrhotic and portal hypertensive rats.

Exposure to low temperatures has been associated with increased gastroesophageal variceal bleeding in patients with cirrhosis and portal hypertension; however, the mechanism remains unclear. Therefore, the aim of the present study was to evaluate the impact of environmental temperature reduction on portal hypertension and the role of adrenergic signaling pathways in this phenomenon. Male Sprague-Dawley rats underwent common bile duct ligation or partial portal vein ligation to induce liver cirrhosis and/or portal hypertension. The impacts of acute or chronic changes in environmental temperature were surveyed. The results showed that acute cooling from 25 to 15°C and 5°C increased the portal pressure by 10.6% and 15.5% in cirrhotic rats, and by 22.2% and 36.1% in portal hypertensive rats, respectively. The transient portal pressure surge started shortly after cooling, reached a peak within 5 min and returned to baseline after 10 min. Systemic vascular resistance, mean arterial pressure and splanchnic blood flow increased significantly at the same time. Plasma epinephrine and norepinephrine concentrations, phospholipase C, protein kinase C activity and myosin phosphorylation of peripheral arteries increased significantly in response to cooling. Phentolamine (an α-blocker) but not propranolol (a non-selective β-blocker) dose-dependently inhibited the transient portal pressure surge and aforementioned molecular changes. In conclusion, environmental temperature reduction induced peripheral vasoconstriction via α-adrenergic pathways, and redistribution of blood flow to the splanchnic system led to a surge in transient portal pressure. Treatment with α-adrenergic receptor antagonists may exert additional benefits in controlling portal hypertension, especially on exposure to low temperatures.

Physiological levels of adrenaline fail to stop pancreatic beta cell activity at unphysiologically high glucose levels.

Adrenaline inhibits insulin secretion from pancreatic beta cells to allow an organism to cover immediate energy needs by unlocking internal nutrient reserves. The stimulation of α2-adrenergic receptors on the plasma membrane of beta cells reduces their excitability and insulin secretion mostly through diminished cAMP production and downstream desensitization of late step(s) of exocytotic machinery to cytosolic Ca2+ concentration ([Ca2+]c). In most studies unphysiologically high adrenaline concentrations have been used to evaluate the role of adrenergic stimulation in pancreatic endocrine cells. Here we report the effect of physiological adrenaline levels on [Ca2+]c dynamics in beta cell collectives in mice pancreatic tissue slice preparation. We used confocal microscopy with a high spatial and temporal resolution to evaluate glucose-stimulated [Ca2+]c events and their sensitivity to adrenaline. We investigated glucose concentrations from 8-20 mM to assess the concentration of adrenaline that completely abolishes [Ca2+]c events. We show that 8 mM glucose stimulation of beta cell collectives is readily inhibited by the concentration of adrenaline available under physiological conditions, and that sequent stimulation with 12 mM glucose or forskolin in high nM range overrides this inhibition. Accordingly, 12 mM glucose stimulation required at least an order of magnitude higher adrenaline concentration above the physiological level to inhibit the activity. To conclude, higher glucose concentrations stimulate beta cell activity in a non-linear manner and beyond levels that could be inhibited with physiologically available plasma adrenaline concentration.