Increase In Systemic Blood Pressure Research Articles

Use of amlodipine in the treatment of cats with systemic hypertension in Japan.

An increase in systemic blood pressure causes bleeding and ischemia owing to peripheral vascular breakdown, leading to various forms of organ damage. The brain, eyes, kidneys, and cardiovascular system are known target organs for hypertension. To our knowledge, no reports in Japan describe, in detail, the types of antihypertensive drugs used to treat hypertension in cats or its underlying causes. Therefore, we aimed to investigate the use of antihypertensive drugs in domestic cats with hypertension in Japan, the causes of hypertension, and the vital prognosis of these patients. In the present survey, we found that amlodipine was used alone (60/80 cats) or concomitantly (20/80 cats) in all cat patients with hypertension in Japan. We also determined that blood pressure measurements were not yet routinely performed on cats at veterinary clinics in Japan. Furthermore, we have new information suggesting that amlodipine administration in cats with hypertension, which lowers systolic arterial pressure levels to within the normal range (<140 mmHg), may have a negative impact on their survival. Routine blood pressure measurements for cats during their regular health checkups can help identify hypertension, and proper interpretation of blood pressure readings can facilitate suitable treatment measures.

Effects of Different Corticosteroid Doses in Elderly Unvaccinated Patients with Severe to Critical COVID-19.

SARS-CoV-2 infection can induce a broad range of clinical symptoms, and the most severe cases are characterized by an uncontrolled inflammatory response with the overproduction of proinflammatory cytokines. Elevated levels of C-reactive protein, interleukin-1B, and interleukin-6 have become key signatures of severe COVID-19. For this reason, the use of 6 mg of dexamethasone has become a standard of care, although this regime may not be optimal. Even though various glucocorticoid doses have been proposed, it is still unclear which dose should be used to prevent adverse effects while at the same time reducing the inflammatory response. Here, we compared two different doses of corticosteroids in 52 elderly hospitalized patients with severe to critical COVID-19 to assess efficacy and safety. We showed that in patients receiving a higher dose of prednisone, the time to negative swab was significantly longer. Furthermore, although neither dose was correlated with the risk of death, patients receiving the high dose were more likely to have adverse events such as hyperglycemia, leukocytosis, an increase in systemic blood pressure, and others. Finally, the BMI, WBC number, and NLR value were directly related to death. In conclusion, although the optimal glucocorticoid dose is still undefined, our retrospective study supports the absence of beneficial effects in the utilization of higher doses of corticosteroids in elderly patients with severe to critical COVID-19.

Malignant Hypertension and the Role of Ophthalmologists: A Review Article.

Malignant hypertension (MHT) is a sudden and severe increase in systemic blood pressure (BP) associated with advanced bilateral retinopathy. It comes under a broader term, called hypertensive emergency, where an acute rise in BP results in end-organ damage. The condition usually requires hospital admission and intensive care management. Although there are lots of sophisticated machines and laboratory tests present to diagnose various organ damage, the role of ophthalmologists will still be at the top. A record of the acute rise of BP to a defining level and simple ophthalmoscopy with high clinical suspicion can save a patient’s life and preserve target organ function by timely referral. So, every ophthalmologist should be aware of this dangerous condition. In this review, we have tried to compile all the current knowledge regarding malignant hypertension that an ophthalmologist may require in day-to-day practice.

The Contribution of Gut Microbiota and Endothelial Dysfunction in the Development of Arterial Hypertension in Animal Models and in Humans.

The maintenance of the physiological values of blood pressure is closely related to unchangeable factors (genetic predisposition or pathological alterations) but also to modifiable factors (dietary fat and salt, sedentary lifestyle, overweight, inappropriate combinations of drugs, alcohol abuse, smoking and use of psychogenic substances). Hypertension is usually characterized by the presence of a chronic increase in systemic blood pressure above the threshold value and is an important risk factor for cardiovascular disease, including myocardial infarction, stroke, micro- and macro-vascular diseases. Hypertension is closely related to functional changes in the endothelium, such as an altered production of vasoconstrictive and vasodilator substances, which lead to an increase in vascular resistance. These alterations make the endothelial tissue unresponsive to autocrine and paracrine stimuli, initially determining an adaptive response, which over time lead to an increase in risk or disease. The gut microbiota is composed of a highly diverse bacterial population of approximately 1014 bacteria. A balanced intestinal microbiota preserves the digestive and absorbent functions of the intestine, protecting from pathogens and toxic metabolites in the circulation and reducing the onset of various diseases. The gut microbiota has been shown to produce unique metabolites potentially important in the generation of hypertension and endothelial dysfunction. This review highlights the close connection between hypertension, endothelial dysfunction and gut microbiota.

Physiology-Enhanced Data Analytics to Evaluate the Effect of Altitude on Intraocular Pressure and Ocular Hemodynamics.

Altitude affects intraocular pressure (IOP); however, the underlying mechanisms involved and its relationship with ocular hemodynamics remain unknown. Herein, a validated mathematical modeling approach was used for a physiology-enhanced (pe-) analysis of the Mont Blanc study (MBS), estimating the effects of altitude on IOP, blood pressure (BP), and retinal hemodynamics. In the MBS, IOP and BP were measured in 33 healthy volunteers at 77 and 3466 m above sea level. Pe-retinal hemodynamics analysis predicted a statistically significant increase (p < 0.001) in the model predicted blood flow and pressure within the retinal vasculature following increases in systemic BP with altitude measured in the MBS. Decreased IOP with altitude led to a non-monotonic behavior of the model predicted retinal vascular resistances, with significant decreases in the resistance of the central retinal artery (p < 0.001) and retinal venules (p = 0.003) and a non-significant increase in the resistance in the central retinal vein (p = 0.253). Pe-aqueous humor analysis showed that a decrease in osmotic pressure difference (OPD) may underlie the difference in IOP measured at different altitudes in the MBS. Our analysis suggests that venules bear the significant portion of the IOP pressure load within the ocular vasculature, and that OPD plays an important role in regulating IOP with changes in altitude.

Dijagnostička i prognostička vrednost selena i selenoproteina P kod bolesnika sa komorbidnim tokom nealkoholne masne bolesti jetre i arterijalne hipertenzije

Objective. To evaluate the diagnostic and prognostic value of Selenoprotein P and selenium in the progression of liver damage in patients with nonalcoholic fatty liver disease (NAFLD). Methods. The study involved 120 patients: 50 with isolated NAFLD, 50 with comorbid NAFLD and hypertension, established according to the global and local guidelines. The control group included 20 relatively healthy volunteers. Liver function parameters, selenium and Selenoprotein P levels were assessed, and predictors of steatohepatitis were identified. Pearson's ch2, Mann-Whitney test, logistic regression was used. Results. The study found significant predominance of levels of Selenoprotein P (Sel P) and selenium in controls (71.0 (54.3; 76.1) ng/ml and 108.0 (96.9; 118.8) ng/ml respectively) compared with the NAFLD + hypertension (19.7 (8.0; 26.7) ng/ml and 43.5 (39.9; 49.1) ng/ml, p &lt;0.001) and the NAFLD group (43.1 (41.3; 45.4) ng/ml and 67.2 (61.5; 77.4) ng/ml, respectively, p &lt;0.001). Regression analysis determined association of Sel P and Sel levels with steatohepatitis: respectively, OR = 1,143 (95.0% CI 1,068-1,224) (p &lt;0.001) and OR = 1,054 (95.0% CI 1,012-1,098) (p = 0.011). Other predictors of steatohepatitis were aspartateaminotransferase (OR = 1,421 (95.0% CI 1,198-1,687), p &lt;0.001) and systolic blood pressure (OR = 1,089 (95.0% CI 1,017-1,116), p = 0.014). Conclusion. Levels of selenium and Selenoprotein P are associated with greater liver damage in patients with NAFLD, and the concomitant increase in systemic blood pressure is an additional factor that adversely affects the course of NAFLD, increasing the intensity of liver damage in such patients.

Understanding the Impact of Hypertension on Left Ventricular Assist Device Pump Function and Thrombotic Risk.

Understanding the Impact of Hypertension on Left Ventricular Assist Device Pump Function and Thrombotic Risk.

Renal interstitial fibroblasts coproduce erythropoietin and renin under anaemic conditions.

BackgroundErythrocyte mass contributes to maintaining systemic oxygen delivery and blood viscosity, with the latter being one of the determinants of blood pressure. However, the physiological response to blood pressure changes under anaemic conditions remain unknown.Methods and FindingsWe show that anaemia decreases blood pressure in human patients and mouse models. Analyses of pathways related to blood pressure regulation demonstrate that anaemia enhances the expression of the gene encoding the vasopressor substance renin in kidneys. Although kidney juxtaglomerular cells are known to continuously produce renin, renal interstitial fibroblasts are identified in the present study as a novel site of renin induction under anaemic hypotensive conditions in mice and rats. Notably, some renal interstitial fibroblasts are found to simultaneously express renin and the erythroid growth factor erythropoietin in the anaemic mouse kidney. Antihypertensive agents but not hypoxic stimuli induced interstitial renin expression, suggesting that blood pressure reduction triggers interstitial renin induction in anaemic mice. The interstitial renin expression was also detected in injured fibrotic kidneys of the mouse and human, and the renin-expressing interstitial cells in murine fibrotic kidneys were identified as myofibroblasts originating from renal interstitial fibroblasts. Since the elevated expression levels of renin in fibrotic kidneys along with progression of renal fibrosis were well correlated to the systemic blood pressure increase, the renal interstitial renin production seemed to affect systemic blood pressure.InterpretationRenal interstitial fibroblasts function as central controllers of systemic oxygen delivery by producing both renin and erythropoietin.FundingGrants-in-Aid from Japan Society for the Promotion of Science (JSPS) KAKENHI (17K19680, 15H04691, and 26111002) and the Takeda Science Foundation.

Renal Interstitial Fibroblasts Coproduce Erythropoietin and Renin Under Anaemic Conditions

Erythrocyte mass contributes to maintaining systemic oxygen delivery and blood viscosity, with the latter being one of the determinants of blood pressure. However, the physiological response to blood pressure changes under anaemic conditions remain unknown. Here, we show that anaemia decreases blood pressure in human patients and mouse models. Analyses of pathways related to blood pressure regulation demonstrate that anaemia enhances the expression of the gene encoding the vasopressor substance renin in kidneys. Although kidney juxtaglomerular cells are known to continuously produce renin, renal interstitial fibroblasts are identified in the present study as a novel site of renin induction under anaemic hypotensive conditions in mice and rats. Notably, some renal interstitial fibroblasts are found to simultaneously express renin and the erythroid growth factor erythropoietin in the anaemic mouse kidney. Antihypertensive agents but not hypoxic stimuli induced interstitial renin expression, suggesting that blood pressure reduction triggers interstitial renin induction in anaemic mice. The interstitial renin expression was also detected in injured fibrotic kidneys of the mouse and human, and the renin-expressing interstitial cells in murine fibrotic kidneys were identified as myofibroblasts originating from renal interstitial fibroblasts. Since the elevated expression levels of renin in fibrotic kidneys along with progression of renal fibrosis were well correlated to the systemic blood pressure increase, the renal interstitial renin production seemed to affect systemic blood pressure. These results propose that renal interstitial fibroblasts function as central controllers of systemic oxygen delivery by producing both renin and erythropoietin.

TRPV1 expressed throughout the arterial circulation regulates vasoconstriction and blood pressure.

The functional roles of the capsaicin receptor, TRPV1, outside of sensory nerves are unclear. We mapped TRPV1 in the mouse circulation, revealing extensive expression in the smooth muscle of resistance arterioles supplying skeletal muscle, heart and adipose tissue. Activation of TRPV1 in vascular myocytes constricted arteries, reduced coronary flow in isolated hearts and increased systemic blood pressure. These functional effects were retained after sensory nerve ablation, indicating specific signalling by arterial TRPV1. TRPV1 mediated the vasoconstrictive and blood pressure responses to the endogenous inflammatory lipid lysophosphatidic acid. These results show that TRPV1 in arteriolar myocytes modulates regional blood flow and systemic blood pressure, and suggest that TRPV1 may be a target of vasoactive inflammatory mediators. The capsaicin receptor, TRPV1, is a key ion channel involved in inflammatory pain signalling. Although mainly studied in sensory nerves, there are reports of TRPV1 expression in isolated segments of the vasculature, but whether the channel localizes to vascular endothelium or smooth muscle is controversial and the distribution and functional roles of TRPV1 in arteries remain unknown. We mapped functional TRPV1 expression throughout the mouse arterial circulation. Analysis of reporter mouse lines TRPV1PLAP-nlacZ and TRPV1-Cre:tdTomato combined with Ca2+ imaging revealed specific localization of TRPV1 to smooth muscle of terminal arterioles in the heart, adipose tissue and skeletal muscle. Capsaicin evoked inward currents (current density ∼10% of sensory neurons) and raised intracellular Ca2+ levels in arterial smooth muscle cells, constricted arterioles ex vivo and in vivo and increased systemic blood pressure in mice and rats. Further, capsaicin markedly and dose-dependently reduced coronary flow. Pharmacological and/or genetic disruption of TRPV1 abolished all these effects of capsaicin as well as vasoconstriction triggered by lysophosphatidic acid, a bioactive lipid generated by platelets and atherogenic plaques. Notably, ablation of sensory nerves did not affect the responses to capsaicin revealing a vascular smooth muscle-restricted signalling mechanism. Moreover, unlike in sensory nerves, TRPV1 function in arteries was resistant to activity-induced desensitization. Thus, TRPV1 activation in vascular myocytes enables a persistent depolarizing current, leading to constriction of coronary, skeletal muscle and adipose arterioles and a sustained increase in systemic blood pressure.

The Benefit of Mean Arterial Pressure Control Using Heart Failure Medical Therapies in Patients Supported by HeartMate 3 LVADs

Introduction Current recommendations for hypertension management in patients with LVADs include the use of neurohormonal antagonists, such as RAAS inhibitors and beta-blockers (BB). HeartMate3 (HM3) LVAD device package insert recommends a goal MAP Methods A single-center, retrospective chart review was conducted for patients with HM3 implantation from 2015-2018. Demographic, medication, laboratory and clinical outcomes data were extracted from an internal database. Patients who died prior to discharge were excluded. Results Patients (n=87) were predominantly Caucasian (82.8%) men (71.3%) with a mean age of 58.1 ± 10.9 years. Co-morbidities included DM (41.4%), hypertension (52.9%), CKD (21.8%) and arrhythmias (62.1%). A MAP of 80-90 mm Hg was achieved in 32% of patients at discharge and in 51% at 6-months (Figure 1A). At discharge, 11.5% of patients were on a RAAS inhibitor, BB and mineralocorticoid receptor antagonists (MRA) compared to 28.7% at 6-months (Figure 1B). Creatinine and MAP did not differ by drug class. The secondary composite outcome at 6-months occurred in 35.8% of patients overall (3 events in patients treated with a combination of RAAS inhibitor with BB and MRA vs 13 in patients without any medical therapy). Conclusion There was an overall increase in systemic blood pressure following surgical recovery 6-months post-HM3 implant, with more than 90% of the cohort sustaining a MAP >80 mm Hg and 40% >90 mm Hg. GDMT with a RAAS inhibitor, BB and MRA was low at discharge (11.5%) with only marginal improvement at 6-months (28.7%), despite adequate MAPs. Factors limiting the titration of GDMT in this population, despite adequate MAP control, warrants further quality improvement investigation.

Effects of dobutamine on cardiovascular function and oxygen delivery in standing horses.

Dobutamine is routinely used to improve cardiovascular function in anaesthetized horses. However, dobutamine in conscious horses is insufficiently investigated. Ten research horses that were already instrumented for a preceding trial were included into the study. Cardiovascular variables were recorded and blood samples taken after instrumentation (Baseline), before starting dobutamine and after 10min of dobutamine infusion (2µgkg-1 min-1 ). A significant increase in systemic blood pressure, mean pulmonary artery pressure and right atrial pressure, and a decrease in heart rate were observed with dobutamine compared with baseline measurements. Arterial and mixed venous haemoglobin and oxygen content, as well as mixed venous partial pressure of oxygen increased. No significant changes in cardiac output, stroke volume, systemic vascular resistance, arterial partial pressure of oxygen, or oxygen consumption, delivery and extraction ratio were detected. Concluding, dobutamine increased systemic blood pressure without detectable changes in stroke volume, cardiac output or systemic vascular resistance in conscious horses.

Endothelin-1 induces a strong pressor effect in ball pythons (Python regius)

Endothelin-1 (ET-1) is a very potent vasoactive peptide released from endothelial cells, and ET-1 plays an important role in the maintenance and regulation of blood pressure in mammals. ET-1 signaling is mediated by two receptors: ETA and ETB. In mammals, ETA receptors are located on vascular smooth muscle where they mediate vasoconstriction. ETB receptors located on the endothelium mediate vasodilatation through the release of nitric oxide, whereas stimulation of ETB receptors placed on vascular smooth muscle leads to vasoconstriction. Less is known about ET-1 signaling in reptiles. In anaesthetized alligators, ET-1 elicits a biphasic blood pressure with a long-lasting initial decrease followed by a smaller increase in systemic blood pressure. In anaesthetized freshwater turtles, ET-1 causes a dose-dependent systemic vasodilatation mediated through ETB receptors. In the present study, we investigated the cardiovascular effects of ET-1 on the systemic and pulmonary vasculature of pythons. The presence of ETA and ETB receptors in the vasculature of pythons was verified by means of immunoblotting. Myography on isolated vessels revealed a dose-dependent vasoconstrictory response to ET-1 in both mesenteric and pulmonary arteries. Pressure measurements in recovered specimens revealed an ET-1-induced rise in systemic blood pressure supporting our in vitro findings. In conclusion, our study shows that ET-1 induces a strong pressor effect in the systemic circulation.

Antioxidant supplements as a novel mean for blocking recurrent heat stress-induced kidney damage following rehydration with fructose-containing beverages

Recently repeated heat stress and dehydration have been reported to cause oxidative stress and kidney damage that is enhanced by rehydrating with fructose solutions. We hypothesized that antioxidants might provide a novel way to prevent kidney damage. To test this hypothesis, mild heat stress was induced by exposing rats to 37 °C during 1 h in a closed chamber. The supplementation with water-soluble antioxidants (Antiox), ascorbic acid 1% plus N-acetyl cysteine 600 mg/L was done either in the 10% fructose 2 h rehydration fluid immediately after heat stress (Fructose 10% + Antiox), and/or in the tap water (Water + Antiox) for the remainder of the day, or in both fluids. After 4 weeks, control rats exposed to heat with fructose rehydration developed impaired renal function, tubular injury, intrarenal oxidative stress, a reduction in Nrf2-Keap1 antioxidant pathway, stimulation of vasopressin and the intrarenal polyol-fructokinase pathway. In contrast, dosing the antioxidants in the tap water (i.e., before the heat exposure and rehydration with fructose) preserved renal function, prevented renal tubule dysfunction and avoided the increase in systemic blood pressure. These effects were likely due to the amplification of the antioxidant defenses through increased Nrf2 nuclear translocation stimulated by the antioxidants and by the prevention of polyol fructokinase pathway overactivation. More studies to understand the mechanisms implicated in this pathology are warranted as there is recent evidence that they may be operating in humans as well.

Expression of troponin subunits in the rat renal afferent arteriole.

Vascular smooth muscle cells of the renal afferent arteriole are unusual in that they must be able to contract very rapidly in response to a sudden increase in systemic blood pressure in order to protect the downstream glomerular capillaries from catastrophic damage. We showed that this could be accounted for, in part, by exclusive expression, at the protein level, of the "fast" (B) isoforms of smooth muscle myosin II heavy chains in the afferent arteriole, in contrast to other vascular smooth muscle cells such as the rat aorta and efferent arteriole which express exclusively the "slow" (A) isoforms (Shiraishi et al. (2003) FASEB. J. 17, 2284-2286). As contraction of the more rapidly contracting striated (skeletal and cardiac) muscles is regulated by the thin filament-associated troponin (Tn) system, we hypothesized that Tn or a Tn-like system may exist in afferent arteriolar cells and contribute to the unusually rapid contraction of this tissue in response to increased intraluminal pressure. We examined the expression of TnC (Ca2+ -binding subunit), TnI (inhibitory subunit), and TnT (tropomyosin-binding subunit) in vascular smooth muscle cells of the rat renal afferent arteriole at the mRNA level. Fast-twitch skeletal muscle and slow-twitch skeletal muscle/cardiac TnC isoforms and slow-twitch skeletal muscle and cardiac TnI isoforms were detected by reverse transcription-polymerase chain reaction (RT-PCR) and confirmed by cDNA sequencing. Furthermore, cardiac and slow-twitch skeletal muscle TnI isoforms, but not fast-twitch skeletal muscle TnI, were detected in isolated afferent arterioles at the protein level by proximity ligation assay. Finally, striated muscle myosin II heavy chain expression was identified in isolated rat afferent arterioles by RT-PCR. We conclude that, in addition to Ca2+ -mediated phosphorylation of myosin II regulatory light chains, contraction of the afferent arteriole may be regulated by a mechanism normally associated with the much more rapidly contracting cardiac and skeletal muscles, which involves Ca2+ binding to TnC, leading to alleviation of inhibition of the actomyosin MgATPase by TnI and tropomyosin and rapid contraction of the vessel.

Abrupt Deflation after Sustained Inflation Causes Lung Injury

Ventilator management in acute respiratory distress syndrome usually focuses on setting parameters, but events occurring at ventilator disconnection are not well understood. To determine if abrupt deflation after sustained inflation causes lung injury. Male Sprague-Dawley rats were ventilated (low Vt, 6 ml/kg) and randomized to control (n = 6; positive end-expiratory pressure [PEEP], 3 cm H2O; 100 min) or intervention (n = 6; PEEP, 3-11 cm H2O over 70 min; abrupt deflation to zero PEEP; ventilation for 30 min). Lung function and injury was assessed, scanning electron microscopy performed, and microvascular leak timed by Evans blue dye (n = 4/group at 0, 2, 5, 10, and 20 min after deflation). Hemodynamic assessment included systemic arterial pressure (n = 6), echocardiography (n = 4), and right (n = 6) and left ventricular pressures (n = 6). Abrupt deflation after sustained inflation (vs. control) caused acute lung dysfunction (compliance 0.48 ± 1.0 vs. 0.82 ± 0.2 m/cm H2O, oxygen saturation as measured by pulse oximetry 67 ± 23.5 vs. 91 ± 4.4%; P < 0.05) and injury (wet/dry ratio 6.1 ± 0.6 vs. 4.6 ± 0.4; P < 0.01). Vascular leak was absent before deflation and maximal 5-10 minutes thereafter; injury was predominantly endothelial. At deflation, left ventricular preload, systemic blood pressure, and left ventricular end-diastolic pressure increased precipitously in proportion to the degree of injury. Injury caused later right ventricular failure. Sodium nitroprusside prevented the increase in systemic blood pressure and left ventricular end-diastolic pressure associated with deflation, and prevented injury. Injury did not occur with gradual deflation. Abrupt deflation after sustained inflation can cause acute lung injury. It seems to be mediated by acute left ventricular decompensation (caused by increased left ventricular preload and afterload) that elevates pulmonary microvascular pressure; this directly injures the endothelium and causes edema, which is potentiated by the surge in pulmonary perfusion.

Distinct roles of angiotensin receptors in autonomic dysreflexia following high-level spinal cord injury in mice

Autonomic dysreflexia (AD), a syndrome caused by loss of supraspinal control over sympathetic activity and amplified vascular reflex upon sensory stimuli below injury level, is a major health problem in high-level spinal cord injury (SCI). After supraspinal sympathetic control of the vasculature below the lesion is lost, the renin-angiotensin system (RAS) is thought to be involved in AD by regulating blood pressure and vascular reactivity. In this study, we aimed to assess the role of different RAS receptors during AD following SCI. Therefore, we induced AD by colorectal distention (CRD) in wild-type mice and mice deficient in the RAS components angiotensin (Ang) II type 1a receptor (AT1a) (Agtr1a−/−) and Ang-(1–7) receptor Mas (Mas−/−) four weeks after complete transection of spinal cord at thoracic level 4 (T4). Systemic blood pressure measurements and wire myography technique were performed to assess hemodynamics and the reactivity of peripheral arteries, respectively. CRD increased mean arterial blood pressure (MAP) and decreased heart rate (HR) in all three animal groups. However, we found less increases in MAP in Mas−/− mice compared to control mice after CRD, whereas AT1a deficiency did not affect the hemodynamic response. We found that the reactivity of wild-type and Mas−/− mesenteric arteries, which are innervated from ganglia distal but close to thoracic level T4, was diminished in response to Ang II in AD after T4-SCI, but this difference was not observed in the absence of AT1a receptors. CRD did not influence the reactivity of femoral arteries which are innervated from ganglia more distal to thoracic level T4, in response to Ang II in AD. In conclusion, we identified a specific role of the Ang-(1–7) receptor Mas in regulating the systemic blood pressure increase in AD in T4-SCI mice. Furthermore, AT1a signaling is not involved in this hemodynamic response, but underlies increased vascular reactivity in mesenteric arteries in response to Ang II, where it may contribute to adaptive changes in regional blood flow.

Irreversible proteasome inhibition with carfilzomib as first line therapy in patients with newly diagnosed multiple myeloma: Early in vivo cardiovascular effects

Patients who experienced cardiovascular side effects during cancer therapy with carfilzomib for multiple myeloma had relapsed multiple myeloma, so have be previously treated with other cancer therapies. The present is a single center cohort study to evaluate early cardiovascular effects of administration of irreversible proteasome inhibitor carfilzomib in naïve patients. We included 24 patients and collected cardiovascular side effects, echocardiographic parameters and endothelial function at baseline and after 4 cycles. At early follow up we observed increase in blood arterial pressure values (mean change in systolic pressure of 10 mmHg (P-value < 0.01; diastolic arterial pressure and mean arterial pressure of 3.3 mmHg and 5.4 mmHg, both P-value < 0.01). Reactive hyperemia PAT index was reduced in the whole cohort by a mean of 0.46 points (P-value < 0.01); diastolic function was changed: E-wave-deceleration-time (EDT) was reduced by 49,96 ± 31 ms, P-value < 0.05 and early diastolic tissue Doppler velocity (e′) by a mean value of 1.46 cm/s, P - value 0.04.At early follow up we did not observe events of grade 3 or 4. We observe correlation between events and endothelial dysfunction at baseline and age (OR 1.9, CI 95% 0.05–5.804, P- value: 0.038 for RHI<1.67; OR 1,4, CI 95%0.99–2.56, P- value: 0.04 for age). Our results suggest that therapy with carfilzomib when used as first line therapy is responsible for increase in systemic blood pressure, alteration of endothelium-mediated vascular dilatation and early myocardial diastolic dysfunction.

Kidney dysfunction in the low-birth weight murine adult: implications of oxidative stress

Maternal undernutrition (MUN) during pregnancy leads to low-birth weight (LBW) neonates that have a reduced kidney nephron endowment and higher morbidity as adults. Using a severe combined caloric and protein-restricted mouse model of MUN to generate LBW mice, we examined the progression of renal insufficiency in LBW adults. Through 6 mo of age, LBW males experienced greater albuminuria (ELISA analysis), a more rapid onset of glomerular hypertrophy, and a worse survival rate than LBW females. In contrast, both sexes experienced a comparable progressive decline in renal vascular density (immunofluorescence analysis), renal blood flow (Laser-Doppler flowmetry analysis), glomerular filtration rate (FITC-sinistrin clearance analysis), and a progressive increase in systemic blood pressure (measured via tail-cuff method). Isolated aortas from both LBW sexes demonstrated reduced vasodilation in response to ACh, indicative of reduced nitric oxide bioavailability and endothelial dysfunction. ELISA and immunofluorescence analysis revealed a significant increase of circulating reactive oxygen species and NADPH oxidase type 4 (NOX4) expression in both LBW sexes, although these increases were more pronounced in males. Although more effective in males, chronic tempol treatment did improve all observed pathologies in both sexes of LBW mice. Chronic NOX4 inhibition with GKT137831 was more effective than tempol in preventing pathologies in LBW males. In conclusion, despite some minor differences, LBW female and male adults have a reduced nephron endowment comparable with progressive renal and vascular dysfunction, which is associated with increased oxidative stress and subsequent endothelial dysfunction. Tempol treatment and/or NOX4 inhibition attenuates renal and vascular dysfunction in LBW adults.

Troponin Subunits are Expressed in the Rat Afferent Arteriole

Vascular smooth muscle cells of the renal afferent arteriole are unusual: they must be able to contract very rapidly in response to a sudden increase in systemic blood pressure, thereby protecting the downstream glomerular capillaries from catastrophic damage. We showed that this could be accounted for in part by exclusive expression, at the protein level, of the “fast” (B) isoforms of smooth muscle myosin II heavy chains in the afferent arteriole, in contrast to other vascular smooth muscle cells such as the rat aorta and efferent arteriole, which express exclusively the “slow” (A) isoforms (Shiraishi M et al (2003) FASEB J 17: 2284–2286). Since contraction of the more rapidly‐contracting striated (skeletal and cardiac) muscles is regulated by the thin filament‐associated troponin (Tn) system, we hypothesized that Tn or a Tn‐like system may exist in afferent arteriolar cells and contribute to the unusually rapid contraction of this tissue in response to increased intraluminal pressure. We examined the expression of TnC (Ca2+‐binding subunit), TnI (inhibitory subunit) and TnT (tropomyosin‐binding subunit) in vascular smooth muscle cells of the rat renal afferent arteriole at the mRNA level. Fast skeletal muscle and slow skeletal muscle/cardiac TnC isoforms and slow skeletal muscle and cardiac TnI isoforms were detected by RT‐PCR and confirmed by cDNA sequencing. Furthermore, cardiac and slow skeletal muscle TnI isoforms, but not fast skeletal muscle TnI were detected in isolated afferent arterioles at the protein level by proximity ligation assay. We conclude that, in addition to Ca2+‐mediated phosphorylation of myosin regulatory light chains, contraction of the afferent arteriole may be regulated by a mechanism normally associated with the much more rapidly contracting cardiac and skeletal muscles, which involves Ca2+ binding to TnC, leading to alleviation of inhibition of the actomyosin MgATPase by TnI and tropomyosin and rapid contraction of the vessel.Support or Funding InformationSupported by the Canadian Institutes of Health ResearchThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.