Exogenous Cortisol Research Articles

6766 Cortisol Pumps: Hospitalizations And Quality Of Life

Abstract Disclosure: A. Tiwari: None. R. Berry: None. A. Mokbel: None. A. Abotouk: None. A.R. Alrifai: None. J. Waleed: None. O. Alzohaili: None. Introduction: Oral regimens of exogenous cortisol fail to mimic physiologic levels. The discrepancy leads to complications, notably nausea, hyperglycemia, and susceptibility to infection. Finer control over cortisol delivery may be achievable with infusion pumps. While international groups have published their experiences with cortisol pumps, these studies often include less than ten patients. We share the largest, single-center cohort ever documented and the first from an American clinic. Methods: We conducted a retrospective cohort study. Through chart review, we identified all patients who received a cortisol pump at a private clinic; these pumps were originally designed to deliver insulin, but we repurposed them for patients with adrenal insufficiency. Clinic notes allowed collection of cortisol dosing pre- and post-exposure to the cortisol pump. We supplemented this information with telephone and digital surveys on the frequency of hospitalization, symptoms, and quality of life; patients provided verbal consent before participation. A Wilcoxon signed rank test and Fisher exact test evaluated significant differences between groups. Results: We identified thirty patients who received a cortisol infusion pump. Our study revealed a statistically significant decrease in hospitalization rate after exposure to a cortisol pump (n=26, mean difference = -5.94 hospitalizations per year, p=0.003), a decrease in the frequency of fatigue (n=25, p=0.0001) and a decrease in the frequency of hypotension (n=25, p=0.005). A validated, quality of life survey corroborated these findings with improvement in twenty-seven out of twenty-eight questions (n=22, p<0.05). However, we did not detect a statistically significant difference in the frequency of eighteen other symptoms nor cortisol dosing between pre- and post-exposure groups. Conclusion: Infusion pumps can better mimic physiological variations in cortisol than oral dosing regimens. We show the extent to which cortisol dosing may reduce hospitalization rate - and therefore cost - as well as improve quality of life. We hope our findings encourage the availability of infusion pumps for adrenal insufficiency, a smaller market that may not otherwise attract commercial investment for a dedicated, randomized trial. Presentation: 6/3/2024

Bone mineral density in patients with Cushing’s syndrome

Objective: Cushing’s syndrome is caused by the excessive secretion of cortisol or the intake of exogenous cortisol. Morbidity caused by osteoporosis is a major complication that cannot be ignored. We conducted a study to evaluate bone density and fracture risk factors in patients with Cushing’s syndrome. Patients and Methods: This retrospective case-control study involved 176 patients diagnosed with Cushing’s syndrome [153 female and 34 male patients] and 84 controls [72 female and 12 male patients]. Patients admitted to the clinics within the last eight years were included in the analysis. We collected demographic, clinic laboratory data, and bone densitometry measurements from electronic patient files. The classification of patients into normal, osteopenia, or osteoporosis groups is determined by their Body Mineral Density measurements based on the World Health Organization criteria. Results: Among the patients, 135 were diagnosed with Cushing’s disease and 41 with adrenal adenomas. Patients with Cushing’ syndrome showed a higher incidence of osteopenia (11.4%) and osteoporosis (2.8%) when compared to the control group. No osteoporosis cases were found in the control group, while nine cases of osteopenia were detected. Osteopenia was significantly more common in adrenal adenoma patients than in those with pituitary Cushing’s disease. Osteopenia was present in 39.1% of adrenal Cushing’s patients, with only 8.7% (n = 2) having osteoporosis. Osteopenia was observed in 11 patients (23.4%) with pituitary Cushing’s disease, while only 4 patients (8.5%) had osteoporosis. Conclusions: Osteopenia is more prevalent in patients with adrenal Cushing’s syndrome.

Pharmacokinetics and pharmacodynamics of endogenous and exogenous cortisol in premenopausal, healthy women

Pharmacokinetics and pharmacodynamics of endogenous and exogenous cortisol in premenopausal, healthy women

Oxidative Stress Induced by Cortisol in Human Platelets.

Hypercortisolism is known to affect platelet function. However, few studies have approached the effect of exogenous cortisol on human platelets, and the results obtained are conflicting and unconvincing. In this study, the effect of exogenous cortisol on several parameters indicative of oxidative status in human platelets has been analysed. We have found that cortisol stimulates ROS production, superoxide anion formation, and lipid peroxidation, with these parameters being in strict correlation. In addition, cortisol decreases GSH and membrane SH-group content, evidencing that the hormone potentiates oxidative stress, depleting platelet antioxidant defence. The involvement of src, syk, PI3K, and AKT enzymes in oxidative mechanisms induced by cortisol is shown. The main sources of ROS in cells can include uncontrolled increase of NADPH oxidase activity and uncoupled aerobic respiration during oxidative phosphorylation. Both mechanisms seem to be involved in ROS formation induced by cortisol, as the NADPH oxidase 1 inhibitor 2(trifluoromethyl)phenothiazine, and rotenone and antimycin A, complex I and III inhibitor, respectively, significantly reduce oxidative stress. On the contrary, the NADPH oxidase inhibitor gp91ds-tat, malate and NaCN, complex II and IV inhibitor, respectively, have a minor effect. It is likely that, in human platelets, oxidative stress induced by cortisol can be associated with venous and arterial thrombosis, greatly contributing to cardiovascular diseases.

Effects of pre-winter cortisol exposure on condition, diet, and morphology of wild juvenile brown trout (Salmo trutta).

Winter is an energetically challenging period for many animals in temperate regions because of the relatively harsh environmental conditions and reduction in food availability during this season. Moreover, stressors experienced by individuals in the fall can affect their subsequent foraging strategy and energy stores after exposure has ended, referred to as carryover effects. We used exogenous cortisol manipulation of wild juvenile brown trout (Salmo trutta) in the fall to simulate a physiological stress response and then investigated short-term (2 weeks) and long-term (4 months) effects on condition metrics (hepatosomatic index and water muscle content), diet (stomach contents and stable isotopes), and morphology during growth in freshwater. We revealed some short-term impacts, likely due to handling stress, and long-term (seasonal) changes in diet, likely reflecting prey availability. Unfortunately, we had very few recaptures of cortisol-treated fish at long-term sampling, limiting detailed analysis about cortisol effects at that time point. Nonetheless, the fish that were sampled showed elevated stable isotopes, suggestive of a cortisol effect long after exposure. This is one of few studies to investigate whether cortisol influences foraging and morphology during juvenile growth, thus extending the knowledge of proximate mechanisms influencing ecologically-relevant phenotypes.

29 The Role of Leptin and Its Regulation in the Hypothalamus of Neonatal Calves

Abstract The constant occurrence of increased feed intake in offspring exposed to intrauterine growth restriction has been noted across multiple species including ruminants. In ruminants, reduced circulating leptin concentrations from birth through the first week or two of life may influence the development of the appetite center of the hypothalamus. It should able be noted that increased circulating cortisol at birth has been associated with this decreased circulating leptin in the perinatal ruminants, yet information is limited as to any cause and effect relationship between the two hormones. The objectives of these studies were to test directly the effects of exogenous cortisol on leptin concentrations relative to development of the hypothalamus in perinatal calves and voluntary feed intake as yearling. In two experiments, Holstein bulls (n = 27) and calves (n = 32 males; n = 30 females) from commercial Angus cows were assigned to treatments at parturition (day 0). Calves were intravenously infused with either a low cortisol [LC; n = 9, 3.5 ug/kg of body weight (BW)], high cortisol (HC; n = 9, 7.0 ug/kg BW), or a control (CON; n = 9, saline). Calves were administered a half dose of their respective treatment 24h postpartum. Jugular vein blood samples were collected before infusion and daily until d 17 or necropsy. At 5 days of age Holstein bull calves were euthanized where cerebral-spinal fluid (CSF) and hypothalamic tissue were collected. Serum and CSF leptin concentrations were analyzed via RIA. Neuronal growth factors were analyzed in hypothalamus samples via qRT-PCR. In experiment 2, yearling calves entered a GROWSAFE System and daily feed intake (FI) measured. Animals were allowed a two-week adjustment period to a growing ration for heifers and a finishing ration for steers. Heifer body condition scores (BCS) were collected at the beginning and end of the trial. Heifers underwent the feeding trial for 70 days and steers until they obtained a back fat (BF) thickness of 1.15 cm. Blood samples were analyzed similar to experiment 1. All data were analyzed via repeated measures using appropriate models of SAS (SAS Institute Inc., Cary, NC). Perinatal dairy bull calves had decreased (P < 0.013) serum and CSF leptin concentrations of HC and LC calves compared with CON. Hypothalamic expression of BDNF, FGF1 and FGF2 were decreased (P < 0.006) in HC and LC compared with CON. During the feeding trial: BW gain, BCS change, and number of feed events were increased (P = 0.001) in LC compared with HC and CON heifers. However, LC observed greater daily FI (P = 0.047) and tended to have greater final BW (P = 0.080) compared with HC and CON steers. In summary, these data support that exogenous cortisol administered to perinatal calves affects leptin production and the appetite center of the hypothalamus when administered during the neonatal period.

Evaluation of the effects of exogenous cortisol manipulation and the glucocorticoid antagonist, RU486, on the exploratory tendency of bluegill sunfish (Lepomis macrochirus)

In teleost fishes, activation of the hypothalamic-pituitary-interrenal axis leads to an elevation of circulating cortisol levels as a primary stress response. While acute elevation of cortisol is generally beneficial, long-term elevation, a common characteristic of chronic stress, may lead to detrimental effects on health and physiological performance in fishes. Some stress-mediated behavioural shifts, such as variation along the shy-boldness axis in fish, may influence individual fitness. The present study evaluated the role of cortisol and its mechanisms of action in the exploratory behaviour of the bluegill sunfish (Lepomis macrochirus). Fish were implanted with cocoa butter alone (sham treatment), or cocoa butter containing cortisol, or cortisol and the glucocorticoid receptor antagonist, RU486. A control (untreated) group was also used. Animals were held for 48 h following treatment and then were subjected to a Z-maze trial to characterize the exploratory behaviour. Cortisol treatment had no measurable effect on the exploratory behaviour of bluegill sunfish. Despite presenting a higher probability of refuge emergence, fish treated with cortisol combined with RU486 behaved similarly to cortisol-treated and control groups. While these results suggest that cortisol may not be involved in the mechanisms controlling boldness, the influence of cortisol elevation across longer time periods plus validation in different contexts will be necessary to confirm this conclusion.

THU611 Circadian Misalignment Of Melatonin Secretion In Adrenal Insufficiency (AI)

Abstract Disclosure: M. Darji: None. S. Pannain: None. S. Sam: None. E. Van Cauter: None. E.C. Hanlon: None. Background: Despite glucocorticoid replacement, the mortality risk of AI remains markedly elevated. Under normal conditions, the circadian rhythm of endogenous cortisol levels is a major internal synchronizing signal between central and peripheral circadian clocks. There is increasing evidence indicating that circadian misalignment has a host of adverse effects, including increased cardio-metabolic risk. The present study aimed to assess circadian function in AI patients, as compared to individually-matched healthy subjects, under controlled laboratory conditions. The 24-h profile of melatonin, normally secreted exclusively at night, was used as the marker of central circadian timing. The 24-h profile of leptin was used as a marker of peripheral circadian function. Methods: Plasma cortisol, melatonin, and leptin were measured over a 24-h period every 30-60 minutes under controlled light-dark, sleep-wake and dietary conditions. A best-fit curve was calculated for each individual hormonal profile using a locally weighted nonlinear regression procedure with a window of 4 hours. The peak and the nadir were defined as the maximum and minimum of the best-fit curve, respectively. The amplitude was defined as half of the difference between the peak and the nadir. Sleep was polygraphically recorded. During daytime hours, the participants completed validated questionnaires assessing Vigor, Mood and Sleepiness. Results: Complete data sets were obtained in 15 AI patients (12 women; age: 47.9 ±12.5 years, BMI: 26.6 ± 12.5 kg/m2; mean ± SD). Twelve AI patients were on hydrocortisone treatment (total dose range: 20 to 40mg/day, number of doses: 1-5 /day) and 3 were on prednisone treatment. Controls (n=15, 12 women) were aged 48.5 ±14.5 years with BMI of 26.5 ± 5.4 kg/m2. The amplitude of the cortisol profile was wider in AI patients, relative to controls, with a higher morning peak and an extended and lower nocturnal nadir. Unexpectedly, we observed a marked difference in the melatonin profile in AI patients as compared to controls. A daytime phase of elevated melatonin levels, culminating prior to lights off while the patients were awake, was detected in 9 of the 15 AI patients. The nocturnal elevation persisted with a similar amplitude to that observed in controls but was advanced by 1-2 hours. The 24-h leptin profile was similar in the two groups. The presence of a daytime melatonin peak in AI patients was associated with lower ratings of vigor and mood, and higher ratings of sleepiness. Conclusion: Glucocorticoid treatment to replace the endogenous levels and circadian rhythmicity of cortisol in AI may impact central circadian timing, resulting in daytime, in addition to nighttime, release of melatonin. This finding suggests that exogenous cortisol replacement that does not mimic a normal 24-h rhythm, may cause central circadian dysfunction and contribute to alterations in mood, vigor and sleepiness. Presentation: Thursday, June 15, 2023

Mineralocorticoid Receptor Mediates Cortisol Regulation of Ionocyte Development in Tilapia (Oreochromis mossambicus)

Cortisol is the predominant corticosteroid in ray-finned fish since it does not possess the aldosterone synthase necessary to produce specific mineralocorticoids. Cortisol is traditionally believed to function as a fish mineralocorticoid. However, the effects of cortisol are mediated through corticosteroid receptors in other vertebrates, and there is an ongoing debate about whether cortisol acts through the glucocorticoid receptor (GR) or the mineralocorticoid receptor (MR) in teleosts. To investigate this issue, we conducted a study using euryhaline Mozambique tilapia (Oreochromis mossambicus) as the experimental species. The experiment was designed to investigate the effect of cortisol on ionocyte development at both the cellular and gene expression levels in tilapia. We administered exogenous cortisol and receptor antagonists, used immunohistochemistry to quantify ionocyte numbers, and performed real-time PCR to assess the expression of the differentiation factor tumor protein 63 (P63) mRNA, an epidermal stem cell marker. We observed that cortisol increased the number of Na+-K+-ATPase (NKA)-immunoactive ionocytes (increased by 1.6-fold) and promoted the gene expression of P63 mRNA (increased by 1.4-fold). Furthermore, we found that the addition of the mineralocorticoid receptor antagonist Spironolactone inhibited the increase in the number of ionocytes (decreased to the level of the control group) and suppressed the gene expression of P63 (similarly decreased to the level of the control group). We also provided evidence for gr, mr, and p63 localization in epidermal cells. At the transcript level, mr mRNA is ubiquitously expressed in gill sections and present in epidermal stem cells (cells labeled with p63), supporting the antagonism and functional assay results in larvae. Our results confirmed that cortisol stimulates ionocyte differentiation in tilapia through the MR, rather than the GR. Therefore, we provide a new direction for investigating the dual action of osmotic regulation and skin/gill epithelial development in tilapia, which could help resolve previously inconsistent and conflicting findings.

Glucocorticoid Receptor Mediates Cortisol Regulation of Glycogen Metabolism in Gills of the Euryhaline Tilapia (Oreochromis mossambicus)

In this study, we investigated the effects of cortisol on the regulation of the glycogen metabolism biomarkers glycogen synthase (GS) and glycogen phosphorylase (GP) in the glycogen-rich cells of the gills of tilapia (Oreochromis mossambicus). In the gills of tilapia, GP, GS, and glycogen were immunocytochemically colocalized in a specific group of glycogen-rich cells adjacent to the gills’ main ionocytes and mitochondria-rich cells. Cortisol plays a vital role in the regulation of physiological functions in animals, including energy metabolism, respiration, immune response, and ion regulation. However, no studies have elucidated the mechanisms regulating cortisol and glycogen-rich cells in the gills. Therefore, we treated tilapia larvae with exogenous cortisol and a glucocorticoid receptor (GR) antagonist to investigate the regulatory mechanisms between cortisol and glycogen-rich cells in the gills. Our results showed that cortisol promoted the expression of gill glycogen phosphorylase isoform (GPGG) mRNA via GR, whereas the GS gene expression remained unaffected. We also found that GR mRNA was colocalized with some glycogen-rich cells in the gills, further confirming our hypothesis that cortisol directly acts on glycogen-rich cells in the gills of tilapia and regulates glycogen metabolism by promoting GPGG mRNA expression.

Accelerated forgetting of a trauma-like event in healthy men and women after a single dose of hydrocortisone

Posttraumatic stress disorder (PTSD) is characterised by dysregulated hypothalamic-pituitary-adrenal axis activity and altered glucocorticoid receptor sensitivity. Early treatment with glucocorticoids may reduce PTSD risk, although the effect of such treatment on the aetiologically critical step of traumatic-memory-formation remains unclear. Here we examine the effects of exogenous cortisol (hydrocortisone) in a preclinical model of PTSD, using a factorial (Drug × Sex), randomised-controlled, double-blind design. Healthy men and women (n = 120) were randomised to receive 30 mg oral hydrocortisone or matched placebo immediately after watching a stressful film. Effects on film-related intrusions were assessed acutely in the lab, and ecologically using daily memory diaries for one week. We found that participants receiving hydrocortisone showed a faster reduction in daily intrusion frequency. Voluntary memory was assessed once, at the end of the week, but was unaffected by hydrocortisone. Exploratory analyses indicated sex-dependent associations between intrusions and baseline estradiol and progesterone levels. In men receiving hydrocortisone, higher baseline estradiol levels were associated with fewer intrusions, whereas women exhibited the opposite pattern. By contrast, progesterone levels were positively associated with intrusions only in men treated with hydrocortisone. The findings suggest that hydrocortisone promotes an accelerated degradation of sensory-perceptual representations underlying traumatic intrusive memories. In addition, while sex alone was not an important moderator, the combination of sex and sex-hormone levels (especially estradiol) influenced hydrocortisone’s effects on involuntary aversive memories. Future well-powered experimental studies may provide a basis for a precision-psychiatry approach to optimising early post-traumatic glucocorticoid treatments that target intrusive memories, based on individual endocrinological profiles.

The Mineralocorticoid Receptor Functions as a Key Glucose Regulator in the Skeletal Muscle of Zebrafish

Glucocorticoids (GCs) are essential for maintaining energy homeostasis as part of the adaptive stress response. Most work to date has characterized the metabolic role of GCs via the activation of the glucocorticoid receptor (nr3c1; GR), which is activated under high GC conditions. However, GCs also bind to the mineralocorticoid receptor (nr3c2; MR), a high-affinity corticosteroid receptor active under basal GC conditions. Despite the expression of MR in skeletal muscles, almost nothing is known about its physiological role. Here we tested the hypothesis that the MR promotes anabolic processes during resting cortisol levels and curtails the catabolic actions of the GR during high (stressed) levels of cortisol. To determine the effect of MR, a zebrafish line with a ubiquitous MR knockout (MRca402/ca402) was utilized. The GR was activated in the same group by chronically treating fish with exogenous cortisol. In the muscle, MR primarily promoted nutrient storage, and restricted energy substrate mobilization under resting conditions, whereas GR activation resulted in increased nutrient utilization. Interestingly, MR loss improved GR-driven metabolic flexibility, suggesting that the activation state of these receptors is a key determinant of skeletal muscle ability to switch fuel sources. To determine if the anabolism-promoting nature of MR was due to an interaction with insulin, fish were co-injected with insulin and the fluorescent glucose analogue 2-NBDG. A loss of MR abolished insulin-stimulated glucose uptake in the skeletal muscle. Taken together, we postulate that MR acts as a key modulator of glucose metabolism in the musculature during basal and stress conditions.

Apoptosis and glucocorticoid-related genes mRNA expression is modulated by coenzyme Q10 supplementation during in vitro maturation and vitrification of bovine oocytes and cumulus cells

Oocyte in vitro maturation (IVM) and vitrification procedures lead to detrimental effects on the overall oocyte quality. The addition of antioxidants during IVM, such as the coenzyme Q10 (Q10), has been demonstrated to positively impact on the cumulus-oocyte complexes due to its role in protection from oxidative damage and modulating gene transcription. Furthermore, glucocorticoids (GC) regulate gene transcription, energy metabolism and apoptosis during the early steps of reproduction. In this sense, most GC actions are mediated by the glucocorticoid receptor (NR3C1), a transcription factor. However, the specific roles of GC in ovarian physiology and oocyte maturation are still unknown. In this regard, a better knowledge on the expression of GC-related and apoptosis-related genes during IVM and cryopreservation procedures could potentially benefit the refinement of assisted reproductive techniques in the bovine species. The present study aims to explore the expression of NR3C1 mRNA in fresh and vitrified bovine oocytes and cumulus cells in response to Q10 (50 μM), and the effect of cortisol addition (0.25 μM, 0.5 μM) on the expression of NR3C1. We also studied the mRNA expression of NR3C1-related genes belonging to the GC regulation pathway, such as hydroxysteroid dehydrogenases (HSD11B1; HSD11B2), immunophilins (FKBP4; FKBP5), signal transducers and activators of transcription (STAT3; STAT5A), the mineralocorticoid receptor (NR3C2), and to the apoptosis pathway, such as the anti- (BCL2) and pro-apoptotic (BAX) mRNA transcripts in oocytes and cumulus cells 1) after IVM, and 2) after vitrification, both in presence or absence of Q10 supplementation during IVM. Our results show that there is an increase in the NR3C1 receptor expression after vitrification of oocytes, but not after exogenous cortisol supplementation during IVM. In addition, Q10 reduces the mRNA expression of HSD11B1 and FKBP5 in oocytes at levels of immature oocytes (HSD11B1 mRNA expression also in cumulus cells), and the BAX:BCL2 ratio mRNA expression. After vitrification in the presence of Q10, HSD11B2 mRNA expression increases in cumulus cells, while HSD11B1 and BAX:BCL2 mRNA expression decreases significantly both in oocytes and cumulus cells. In conclusion, our results show for the first time the effect of IVM, vitrification and Q10 supplementation on the mRNA relative expression of GC-related and apoptosis genes, and the effect of vitrification in the protein expression of NR3C1.

Cortisol safeguards oogenesis by promoting follicular cell survival.

The role of glucocorticoids in oogenesis remains to be elucidated. cyp11c1 encodes the key enzyme involved in the synthesis of cortisol, the major glucocorticoid in teleosts. In our previous study, we mutated cyp11c1 in tilapia and analyzed its role in spermatogenesis. In this study, we analyzed its role in oogenesis. cyp11c1+/- XX tilapia showed normal ovarian morphology but poor egg quality, as indicated by the mortality of embryos before 3 d post fertilization, which could be partially rescued by the supplement of exogenous cortisol to the mother fish. Transcriptome analyses revealed reduced expression of maternal genes in the eggs of the cyp11c1+/- XX fish. The cyp11c1-/- females showed impaired vitellogenesis and arrested oogenesis due to significantly decreased serum cortisol. Further analyses revealed decreased serum E2 level and expression of amh, an important regulator of follicular cell development, and increased follicular cell apoptosis in the ovaries of cyp11c1-/- XX fish, which could be rescued by supplement of either exogenous cortisol or E2. Luciferase assays revealed a direct regulation of cortisol and E2 on amh transcription via GRs or ESRs. Taken together, our results demonstrate that cortisol safeguards oogenesis by promoting follicular cell survival probably via Amh signaling.

Differential Metabolic and Transcriptional Responses of Gilthead Seabream (Sparus aurata) Administered with Cortisol or Cortisol-BSA.

Cortisol is the main glucocorticoid hormone promoting compensatory metabolic responses of stress in teleosts. This hormone acts through genomic and membrane-initiated actions to exert its functions inside the cell. Experimental approaches, using exogenous cortisol administration, confirm the role of this hormone during short (minutes to hours)- and long-term (days to weeks) responses to stress. The role of membrane-initiated cortisol signaling during long-term responses has been recently explored. In this study, Sparus aurata were intraperitoneally injected with coconut oil alone or coconut oil containing cortisol, cortisol-BSA, or BSA. After 3 days of treatment, plasma, liver, and skeletal muscle were extracted. Plasma cortisol, as well as metabolic indicators in the plasma and tissues collected, and metabolism-related gene expression, were measured. Our results showed that artificially increased plasma cortisol levels in S. aurata enhanced plasma glucose and triacylglycerols values as well as hepatic substrate energy mobilization. Additionally, cortisol stimulated hepatic carbohydrates metabolism, as seen by the increased expression of metabolism-related genes. All of these responses, observed in cortisol-administered fish, were not detected by replicating the same protocol and instead using cortisol-BSA, which exclusively induces membrane-initiated effects. Therefore, we suggest that after three days of cortisol administration, only genomic actions are involved in the metabolic responses in S. aurata.

Cortisol differentially affects the viability and myogenesis of mono- and co-cultured porcine gluteal muscles satellite cells and fibroblasts

Cortisol is a ubiquitously expressed stress hormone. In this study, we investigated the effects of exogenous cortisol on porcine gluteal muscles primary cultured satellite cells and fibroblasts. Satellite cells and fibroblasts were mono-or co-cultured, and cells in each type of culture were categorized into the control and cortisol-treated (treatment) groups. We selected 28 μmol mL−1 cortisol for treatment based on their efficacy. Cortisol treatment reduced viability of monocultured satellite cells and fibroblasts. In both monocultured and co-cultured cells, the nucleus in the treatment group was damaged than that control group. Moreover, the total cell cycle duration was shorter in the treatment group than the control group. PAX-7 expression was upregulated in the control group of co-cultured satellite cells and fibroblasts than those remaining groups. Moreover, MyoD expression was downregulated in the cortisol treated group of both mono-and co-cultured satellite cells compared with that in the control group. In co-cultured fibroblasts, MyoD and MyoG expression was upregulated than those remaining groups. The Cyto-C expression was upregulated in the treatment group compared to the control mono-and co-cultured both cells. These results suggest that the selected experimental dose of cortisol reduced cell viability and myogenesis-related gene expression in the monoculture compared to that in the co-culture of satellite cells and fibroblasts.

Effects of Exogenous Glucocorticoid Administration on Appetitic Center Brain Development in Dairy Bull Calves

Abstract The objective of study was to determine the effects of exogenous cortisol on leptin concentrations and appetitic center development of perinatal dairy bull calves. Holstein bull calves (n = 27) were weighed and randomly assigned to treatments within 4 h of parturition (d0). Each calf was intravenously infused with either a low cortisol (LC; n = 9, 3.5 ug/kg of BW), high cortisol (HC; n = 9, 7.0 ug/kg of BW), or a sham infusion control (CON; n = 9, similar volume of saline). Each calf was administered a second infusion (half dose) of its respective treatment 24 h postpartum. All calves were housed similarly and fed milk replacer (28% CP, 20% fat) three times daily. Blood was collected via jugular venipuncture before infusion and from d 0–5 of age. At 5 d of age, calves were euthanized via sodium pentobarbital overdose. Cerebral-spinal fluid (CSF) from the third ventricle of the brain, hypothalamus, and adipose tissue (AT; omental, perirenal, and mesenteric) were collected. Blood and CSF samples were analyzed for leptin concentrations via a validated RIA. Adipose tissue samples were analyzed via western blotting for leptin and glucocorticoid receptor (GR) expression and normalized to glyceraldehyde 3-phosphate dehydrogenase (GAPDH) expression. Hypothalamus samples were analyzed via qRT-PCR for genes associated with neuronal growth factors and normalized to the average of two housekeeping genes. All data were analyzed via ANOVA or repeated measures analysis using appropriate models (SAS Institute Inc., Cary, NC). Serum and CSF leptin concentrations were decreased (P < 0.013) in HC and LC compared to CON. Leptin protein expression was decreased (P < 0.044) in perirenal and omental AT of LC calves compared to CON. Hypothalamic expression of BDNF, FGF1, and FGF2 were decreased (P < 0.006) in HC and LC compared to CON. In summary, exogenous cortisol administered to calves at birth reduced leptin concentrations and altered appetitic control center development of the brain.

Effects of Exogenous Glucocorticoid Administration on Feed Intake in Beef Cattle

Abstract Calves (n = 63) from Angus crossbred cows were weighed and randomly assigned to treatments within 4 h of parturition (d 0). Each calf was intravenously infused with either a low cortisol [LC; n = 22, 3.5 µg hydrocortisol sodium succinate/kg body weight (BW)], high cortisol (HC; n = 20, 7.0 µg/kg BW), or a sham infusion control (CON; n = 21, similar volume of saline). Each calf was administered a second infusion of its respective treatment 24 h postpartum. Blood was collected via jugular venipuncture before infusion and daily from d 0–17 of age and analyzed for leptin concentrations using a validated radioimmunoassay. Animal BW was collected every 14 d from d 0 until the end of the study. Heifers (n = 31; 367±4 d of age) and steers (n = 32; 385±4 d of age) entered a Growsafe system to measure feed intake (FI) and were allowed a 2-wk adjustment period to a commercial ration (1.27 Mcal NEm/kg and 15.8% CP and 0.45 Mcal NEg/kg and 13.8% CP, respectively; DM basis). Heifer body condition score (BCS) was collected at the beginning and end of the trial. Heifers were fed for 70 d and steers until they obtained a 12th rib back fat (BF) thickness of 1.15 cm. Data were analyzed via ANOVA or repeated measures using appropriate models of SAS. Serum leptin concentrations observed a treatment by day interaction (P = 0.0028), in which HC and LC were decreased compared to CON from d 2–17 of age. Calf birth BW and adjusted 205-d BW did not differ (P > 0.056) between treatments. Heifer BW gain, BCS change, and number of feed events were increased (P = 0.001) in LC compared to HC and CON. Steers did not differ between treatments (P > 0.080) in BW, BW gain, or BF thickness. However, LC steers observed greater daily FI (P = 0.047) and tended to have greater final BW (P = 0.080). In summary, exogenous cortisol administered to calves at parturition reduced leptin concentrations and improved FI of beef steers during a feeding trial.

Controlled experiments to explore the use of a multi-tissue approach to characterizing stress in wild-caught Pacific halibut (Hippoglossus stenolepis)

The integration of multiple tissues in physiological and ecological analyses can enhance methodological approaches, increase applications for data and extend interpretation of results. Previous investigations of the stress response in fish have focused primarily on cortisol levels in a single matrix-blood plasma-which confines interpretations of cortisol levels to a short temporal frame. Epidermal mucus has been proposed as an alternative or complement to plasma that may provide a view to cortisol levels over a different temporal window allowing comparative assessment. Here, we explore the potential for multi-tissue cortisol analysis using both plasma and epidermal mucus in Pacific halibut (Hippoglossus stenolepis). The relative timing at which cortisol increased and decreased in the two matrices as well as cortisol concentrations at estimated peak levels were compared in two trials after (i) inducing cortisol synthesis by adrenocorticotropic hormone (ACTH1-24) administration and (ii) inducing cortisol elimination using cortisol (hydrocortisone, 98%) injection. The ACTH treatment elicited a peak plasma cortisol response approximately 12hours post-injection, while mucus cortisol concentrations peaked later at approximately 62hours post-injection. Exogenous cortisol treatments suggested relatively little transfer of cortisol from plasma to mucus, potentially reflecting differential effects of endogenous and exogenous cortisol. Our results suggest the potential utility of mucus as a sampling matrix that provides an extended window for detection of the stress response as compared to plasma. Results also suggest the utility of a multi-tissue approach to cortisol analysis with potential applications to applied fisheries research. Increased understanding of the relative scale of the cortisol response to stress (e.g. capture) will allow researchers and managers to better interpret the physiological condition and survival outcome of fish subjected to regulatory discard.

60 Effects of exogenous glucocorticoid administration on leptin concentrations in perinatal dairy bull calves

Abstract Previous studies suggest a relationship between leptin and cortisol immediately postpartum is linked to improved feedlot efficiency on cattle exposed to perinatal stressors. The objective of the current study was to determine the effects of exogenous cortisol administration on circulating leptin concentrations in perinatal dairy bull calves. Within four hours of parturition, Holstein bull calves were randomly assigned to treatments and intravenously infused with low cortisol (LC; n =9, 3.5 ug/kg of cortisol), high cortisol (HC; n = 9, 7.0 ug/kg of cortisol), or a sham infusion control (CON; n = 9, similar volume of saline). Calves were housed similarly and fed milk replacer (28% CP, 20% fat) three times daily. Blood collections were performed via jugular venipuncture using Z/9mL serum collection tubes (Sarstedt, Newton, NC) from d 0 to 5 of age. Serum samples were incubated for 1 h at room temperature then overnight at 4°C, centrifuged at 1800 x g at 4°C for 20 minutes, serum decanted, and stored long term at -20°C until analysis. At 5 d of age, calves were euthanized utilizing an overdose of sodium pentobarbital (Schering-Plough Animal Health, Union, NJ) and cerebral-spinal fluid (CSF) from the third ventricle of the brain was collected and stored at -80°C until analysis. All samples were analyzed for leptin concentrations via a previously-validated radioimmunoassay. Serum leptin concentrations were analyzed via repeated measures of ANOVA and CSF leptin concentrations via the GLM procedure of SAS (SAS Institute Inc., Cary, NC, USA). Serum leptin concentrations of HC and LC were decreased (P = 0.013) compared to CON, and d 0 was decreased (P < 0.001) compared to all other days of age. Cerebral-spinal fluid leptin concentrations of HC and LC were decreased (P = 0.005) compared to CON. In summary, exogenous cortisol administered to perinatal dairy bull calves reduced leptin concentrations in serum and CSF.