Venous endothelium dysfunction is also presented in hypertensive patients

Univ São Paulo, Sch Med, Inst Heart, São Paulo, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc

Effect of simvastatin in the autonomic system is dependent on the increased gain/sensitivity of the baroreceptors

A number of mechanisms have been proposed to explain the pleiotropic effect of statin therapy to reduce sympathetic outflow in cardiovascular disease. We tested the hypothesis that statin treatment could improve baroreflex gain-sensitivity triggered by morphological adaptations in the mechanoreceptor site, thus reducing sympathetic activity, regardless of arterial pressure (AP) level reduction. Male spontaneously hypertensive rats (SHR) were divided into control (SHR, n = 8) and SHR-simvastatin (5 mg/kg/day, for 7 days) (SHR-S, n = 8). After treatment, AP, baroreflex sensitivity (BRS) in response to AP-induced changes, aortic depressor nerve activity, and spectral analyses of pulse interval (PI) and AP variabilities were performed. Internal and external carotids were prepared for morphoquantitative evaluation. Although AP was similar between groups, sympathetic modulation, represented by the low frequency band of PI (SHR: 6.84 ± 3.19 vs. SHR-S: 2.41 ± 0.96 msec2) and from systolic AP variability (SHR: 3.95 ± 0.36 vs. SHR-S: 2.86 ± 0.18 mmHg2), were reduced in treated animals. In parallel, simvastatin induced an increase of 26% and 21% in the number of elastic lamellae as well as a decrease of 9% and 25% in the carotid thickness in both, external and internal carotid, respectively. Moreover, improved baroreceptor function (SHR: 0.78 ± 0.03 vs. SHR-S: 1.06 ± 0.04% mv/mmHg) was observed in addition to a 115% increase in aortic depressor nerve activity in SHR-S rats. Therefore, our data suggest that the reduction of sympathetic outflow in hypertension by simvastatin treatment may be triggered by structural changes in the carotid arteries and increased BRS in response to an improvement of the baroreceptors discharge and consequently of the afferent pathway of the baroreflex arch.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP- 01/00,009-0; 2012/20,141-5)Fundação E.J. ZerbiniConselho Nacional de Pesquisa e Desenvolvimento (CNPq

Reduced cortical renal GLUT1 expression induced by angiotensin-converting enzyme inhibition in diabetic spontaneously hypertensive rats

Diabetes in spontaneously hypertensive rats is associated with cortical renal GLUT1 and GLUT2 overexpression. Our objective was to evaluate the effect of the angiotensin-converting enzyme blockade on cortical renal GLUT1 and GLUT2 expression, urinary albumin and urinary TGF-β1. Streptozotocin, 50 mg/kg, or citrate buffer (N = 16) was administered as a single injection into the tail vein in adult spontaneously hypertensive rats (~260 g). Thirty days later, these diabetic spontaneously hypertensive rats received ramipril by gavage: 0.01 mg·kg-1·day-1 (D0.01, N = 14), 1 mg·kg-1·day-1 (D1, N = 9) or water (D, N = 11) for 15 days. Albumin and TGF-β1 (24-h urine), direct arterial pressure, renal tissue angiotensin-converting enzyme activity (fluorometric assay), and GLUT1 and GLUT2 protein levels (Western blot, renal cortex) were determined. Glycemia and glycosuria were higher (P < 0.05) in the diabetic rats compared with controls, but similar between the diabetic groups. Diabetes in spontaneously hypertensive rats lowered renal tissue angiotensin-converting enzyme activity (40%), which was reduced further when higher ramipril doses were used. Diabetes associated with hypertension raised GLUT1 by 28% (P < 0.0001) and GLUT2 by 76% (P = 0.01), and both doses of ramipril equally reduced cortical GLUT1 (D vs D1 and vs D0.01, P ≤ 0.001). GLUT2 levels were reduced in D0.01 (P < 0.05 vs D). Diabetes increased urinary albumin and TGF-β1 urinary excretion, but the 15-day ramipril treatment (with either dose) did not reduce them. In conclusion, ramipril is effective in lowering renal tissue angiotensin-converting enzyme activity, as well as blocking cortical GLUT1 overexpression, which may be beneficial in arresting the development of diabetic nephropathy

Enteral administration of the protease inhibitor gabexate mesilate preserves vascular function in experimental trauma/hemorrhagic shock.

Preserving vascular function is crucial for preventing multiorgan failure and death in ischemic and low-pressure states such as trauma/hemorrhagic shock (T/HS). It has recently been reported that inhibiting circulating proteases released from the bowel to the circulation during T/HS may preserve vascular function and improve outcomes following T/HS. This study aimed to evaluate the role of the serine protease inhibitor gabexate mesilate (GM) in preserving vascular function during T/HS when given enterally. We studied the vascular reactivity of mesenteric arteries from male Wistar rats treated with enteral GM (10&nbsp;mg/kg) (GM-treated, n = 6) or control (Shock-control, n = 6) following (T/HS) using pressure myography. Concentration-response curves of endothelial-dependent and endothelial-independent agonists (e.g., acetylcholine, sodium nitroprusside) ranging from 10-10 to 10-5&nbsp;M were performed. In a second set of experiments, ex-vivo arteries from healthy rats were perfused with plasma from shocked animals from both groups and vascular performance was similarly measured. Arteries from the GM-treated group demonstrated a preserved concentration-response curve to the α1 adrenergic agonist phenylephrine compared to arteries from Shock-control animals (- logEC50: - 5.73 ± 0.25 vs. - 6.48 ± 0.2, Shock-control vs. GM-treated, p = 0.04). When perfused with plasma from GM-treated rats, healthy arteries exhibited an even greater constriction and sensitivity to phenylephrine (- logEC50: - 6.62 ± 0.21 vs. - 7.13 ± 0.21, Shock-control vs. GM-treated, p = 0.02). Enteral GM also preserved the endothelium-dependent vascular response to agonists following T/HS and limited syndecan-1 shedding as a marker of glycocalyx compromise (41.84 ± 9 vs. 17.63 ± 3.97&nbsp;ng/mL, Shock-control vs. GM-treated, p = 0.02). Syndecan-1 cleavage was correlated with plasma trypsin-like activity (r2 = 0.9611). Enteral gabexate mesilate was able to maintain vascular function in experimental T/HS, which was reflected by improved hemodynamics (mean arterial pressure 50.39 ± 7.91 vs. 64.95 ± 3.43&nbsp;mmHg, Shock-control vs. GM treated, p = 0.0001). Enteral serine protease inhibition may be a potential therapeutic intervention in the treatment of T/HS

Factors associated with health-related quality of life after successful kidney transplantation: a population-based study

Kidney transplantation improves the quality of life of end-stage renal disease patients. The quality of life benefits, however, pertain to patients on average, not to all transplant recipients. The aim of this study was to identify factors associated with health-related quality of life after kidney transplantation. Population-based study with a cross-sectional design was carried out and quality of life was assessed by SF-36 Health Survey Version 1. A multivariate linear regression model was constructed with sociodemographic, clinical and laboratory data as independent variables. Two hundred and seventy-two kidney recipients with a functioning graft were analyzed. Hypertension, diabetes, higher serum creatinine and lower hematocrit were independently and significantly associated with lower scores for the SF-36 oblique physical component summary (PCSc). The final regression model explained 11% of the PCSc variance. The scores of oblique mental component summary (MCSc) were worse for females, patients with a lower income, unemployed and patients with a higher serum creatinine. The regression model explained 9% of the MCSc variance. Among the studied variables, comorbidity and graft function were the main factors associated with the PCSc, and sociodemographic variables and graft function were the main determinants of MCSc. Despite comprehensive, the final regression models explained only a little part of the heath-related quality of life variance. Additional factors, such as personal, environmental and clinical ones might influence quality of life perceived by the patients after kidney transplantation