Endothelial caveolin-1 (cav-1) is an anchoring protein in plasma membrane caveolae where it binds endothelial nitric oxide synthase (eNOS) and limits its activation, particularly in animals fed a high salt (HS) diet. Cav-1 also interacts with steroid receptors such as the mineralocorticoid receptor (MR). To test the hypothesis that vascular reactivity is influenced by an interplay between MR and cav-1 during HS diet, we examined the effects of MR blockade on NOS-mediated vascular relaxation in normal and cav-1-deficient mice. Wild-type (WT) and cav-1 knockout mice (cav-1(-/-)) were fed for 14 days a HS (4% NaCl) diet with and without the MR antagonist eplerenone (Epl; 100 mg x kg(-1) x day(-1)). After systolic blood pressure (BP) was measured, the thoracic aorta was isolated for measurement of vascular reactivity, and the aorta and heart were used for measurement of eNOS and MR expression. BP was not different between WT + Epl and WT, but was higher in cav-1(-/-) + Epl than in cav-1(-/-) mice. Phenylephrine (Phe)-induced vascular contraction was less in cav-1(-/-) than WT, and significantly enhanced in cav-1(-/-) + Epl than in cav-1(-/-), but not in WT + Epl compared with WT. Endothelium removal and NOS blockade by N(omega)-nitro-l-arginine methyl ester (l-NAME) enhanced Phe contraction in cav-1(-/-), but not cav-1(-/-) + Epl. ACh-induced aortic relaxation was reduced in cav-1(-/-) + Epl versus cav-1(-/-), but not in WT + Epl compared with WT. Endothelium removal, l-NAME, and the guanylate cyclase inhibitor ODQ abolished the large ACh-induced relaxation in cav-1(-/-) and the remaining relaxation in the cav-1(-/-) + Epl but had similar inhibitory effect in WT and WT + Epl. Real-time RT-PCR indicated decreased eNOS mRNA expression in the aorta and heart, and Western blots revealed decreased total eNOS in the heart of cav-1(-/-) + Epl compared with cav-1(-/-). Vascular and cardiac MR expression was less in cav-1(-/-) than WT, but not in cav-1(-/-) + Epl compared with cav-1(-/-). Plasma aldosterone (Aldo) was not different between WT and cav-1(-/-) mice nontreated or treated with Epl. Thus in cav-1 deficiency states and HS diet MR blockade is associated with increased BP, enhanced vasoconstriction, and decreased NOS-mediated vascular relaxation and eNOS expression. The data suggest that, in the absence of cav-1, MR activation plays a beneficial role in regulating eNOS expression/activity and, consequently, the vascular function during HS diet.

Normal pregnancy is associated with significant hemodynamic changes in the cardiovascular system in order to meet the metabolic demands of mother and fetus. These changes include increased cardiac output, decreased vascular resistance, and vascular remodeling in the uterine and systemic circulation. Preeclampsia (PE) is a major complication of pregnancy characterized by proteinuria and hypertension. Several risk factors have been implicated in the pathogenesis of PE including genetic and dietary factors. Ca 2+ is an essential dietary element and an important regulator of many cellular processes including vascular function. The importance of adequate dietary Ca 2+ intake during pregnancy is supported by many studies. Pregnancy-associated changes in Ca 2+ metabolism and plasma Ca 2+ have been observed. During pregnancy, changes in intracellular free Ca 2+ concentration ([Ca 2+ ] i ) have been described in red blood cells, platelets and immune cells. Also, during pregnancy, an increase in [Ca 2+ ] i in endothelial cells (EC) stimulates the production of vasodilator substances such as nitric oxide and prostacyclin. Normal pregnancy is also associated with decreased vascular smooth muscle (VSM) [Ca 2+ ] i and possibly the Ca 2+ -sensitization pathways of VSM contraction including protein kinase C, Rho-kinase, and mitogen-activated protein kinase. Ca 2+ -dependent matrix metalloproteinases could also promote extracellular matrix degradation and vascular remodeling during pregnancy. Disruption in the balance between dietary, plasma and vascular cell Ca 2+ may be responsible for some of the manifestation of PE including procoagulation, decreased vasodilation, and increased vasoconstriction and vascular resistance. The potential benefits of Ca 2+ supplements during pregnancy, and the use of modulators of vascular Ca 2+ to reduce the manifestations of PE in susceptible women remain an important area for experimental and clinical research.

Background: Anastomotic leaks after low anterior resection for rectal cancer remain the most feared complication. The aim of our study was to investigate whether the use of a transanal tube could reduce the leakage rate after this surgical procedure. Methods: This is a retrospective analysis of a single-institution experience. The study includes 66 patients who underwent low anterior resection for rectal cancer without stoma creation between January 2008 and June 2013. Patients were divided into two groups, i.e. those with a transanal drainage tube (TT; n = 9) and those without tube (NTT; n = 57), and evaluated for clinically evident anastomotic leakage and postoperative complications. Results: The postoperative anastomotic leakage appeared in 5 patients (9%) in the NTT group while no single case was observed within the TT group. Despite the disadvantageous background in the TT group (a transanal stent was used in the most high-risk patients), these patients had no postoperative complications. In the NTT group, 23% had some kind of postoperative complications, and 5% died. The difference between the two groups is not significant. Conclusions: Our study showed that the use of a transanal tube in low anterior resection for rectal cancer could potentially be a simple and effective method of reducing anastomotic leakage. In order to prove our observations, larger prospective randomized studies should be performed.

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