Effect of Angiotensin receptor blockade on Plasma Osmolality and Neurohumoral Responses to High Environmental Temperature in Rats Fed a High Salt Diet.

Plasma osmolality (pOsmol) and neurohumoral signals play important roles in the pathophysiology of cardiovascular diseases. Our study investigated the effect of high environmental temperature (HET) on neurohumoral responses and pOsmol in rats fed a high salt diet (HSD), with and without angiotensin II receptor blockade (ARB), using telmisartan.  Fifty-six male 8-week old Sprague-Dawley rats (95-110g) were randomly assigned into seven groups of 8 rats.

Angiotensin receptor blockade with Losartan attenuates pressor response to handgrip contraction and enhances natriuresis in salt loaded hypertensive subjects: a quasi-experimental study among Nigerian adults.

Introduction: Sympathetic and Renin-Angiotensin-Aldosterone systems play crucial roles in blood pressure response to increased salt intake. This study investigated the effects of angiotensin receptor blocker (ARB) and sympathetic excitation on the responses of blood pressure (BP) and peripheral vascular resistance (PVR) in salt loaded normotensive (NT) and hypertensive (HT) Nigerian subjects.

Methods: 16 NT and 14 HT participants, that were age-matched [39.

Sex differences in cardiac and renal responses to a high salt diet in Sprague-Dawley rats.

High dietary salt intake is an important risk factor for cardiovascular and renal diseases. However, sexual disparity exists in the response of target organs to high salt diet (HSD). To determine how sex affects cardiac and renal functions' response to HSD, 20 weanling Sprague-Dawley rats (10 males and 10 females) were divided into 4 groups of 5 rats each.

Epithelial sodium channel blockade and new β-ENaC polymorphisms among normotensive and hypertensive adult Nigerians.

We sought to determine the effect of amiloride on blood pressure (BP) and the presence of polymorphisms of the β-subunit of the epithelial sodium channel (ENaC) among normotensive (NT) and hypertensive (HT) Nigerians. Healthy volunteers-47 NT and 53 age-matched HT were recruited after giving informed consent. Subjects were salt-loaded with 200 mmol of NaCl daily for 5 days.

Volume regulatory hormones and plasma volume in pregnant women with sickle cell disorder.

Background: Sickle cell disease (haemoglobin SS (HbSS)) mainly affects those of West African origin and is associated with hypervolaemia. Plasma volume rises by up to 50% in normal pregnancy but was previously found to be paradoxically contracted in late sickle cell pregnancy. The renin-angiotensin-aldosterone system is activated very early in human pregnancy to support the plasma volume expansion.

Orchidectomy attenuates high-salt diet-induced increases in blood pressure, renovascular resistance, and hind limb vascular dysfunction: role of testosterone.

Sex hormone-dependent vascular reactivity is an underlying factor contributing to sex differences in salt-dependent hypertension. This study evaluated the role of androgens (testosterone) in high salt-induced increase in blood pressure (BP) and altered vascular reactivity in renal blood flow and perfused hind limb preparation. Weanling male rats (8 weeks old, 180-200 g) were bilaterally orchidectomised or sham operated with or without testosterone replacement (Sustanon 250, 10 mg/kg intramuscularly once in 3 weeks) and placed on a normal (0.

Testosterone reduces vascular relaxation by altering cyclic adenosine monophosphate pathway and potassium channel activation in male Sprague Dawley rats fed a high-salt diet.

Objectives: Male gender and high-salt diet are risk factors for hypertension. The effect of chronic exposure to testosterone is an increase in vascular tone but its influence upon responses induced by other vasoactive agents is not clear. We considered the possibility of interactions between testosterone and a high-salt diet in the mechanisms that are involved in the regulation of vascular tone.

Relaxation response of abdominal aorta to androgens in orchidectomised Sprague-Dawley rats fed a high-salt diet.

Previous studies have demonstrated the acute relaxant effects of androgens on normal arterial beds, but not on any with underlying or induced pathologies. This study investigated whether the status of the gonads affects the direct actions of androgens on isolated abdominal aorta from male Sprague-Dawley rats fed a high-salt diet. A high-salt diet reduced the relaxation response to exogenous testosterone, but not to dehydroepiandrosterone (DHEA).

Differential responses to endothelial-dependent relaxation of the thoracic and abdominal aorta from male Sprague-Dawley rats.

Regional heterogeneity exists in reactivity of different vascular beds to vasoactive substances. Experiments were designed to determine if there are differences between thoracic and abdominal aorta response to acetylcholine-induced relaxation. Ten male Sprague-Dawley rats with a weighing between 200g-250g were used.

Testosterone relaxes abdominal aorta in male Sprague-Dawley rats by opening potassium (K(+)) channel and blockade of calcium (Ca(2+)) channel.

Aim: To investigate the direct effect of testosterone and its precursor/derivative dehydroepiandrosterone (DHEA) on isolated rat abdominal aortic rings.

Materials And Methods: 3mm abdominal aortic rings that were obtained from 3 months old male Sprague-Dawley rats were suspended in organ baths containing Hepes buffered PSS bubbled with 100% oxygen. Relaxation response to testosterone and DHEA was studied in noradrenalin pre-contracted rings.

Link between free radicals and protein kinase C in glucose-induced alteration of vascular dilation.

Development of vascular complications in diabetes has been linked to the quality of glucose regulation and characterized by endothelial dysfunction. The exact mechanism behind vascular complications in diabetes is poorly understood. However, alteration of nitric oxide (NO) biosynthesis or bioactivity is strongly implicated and the mechanism behind such alterations is still a subject for research investigations.

High salt diet modulates cAMP- and nitric oxide-mediated relaxation responses to isoproterenol in the rat aorta.

This study tested the hypothesis that nitric oxide (NO) production contributes to relaxation induced by 3',5'-cyclic adenylate monophosphate (cAMP)-elevating agents and that high salt diet impairs this mechanism of relaxation. Relaxation response to isoproterenol but not sodium nitroprusside, a NO donor, was reduced in the thoracic aorta from rats that were placed on a high salt diet (8% NaCl; 60+/-4%, P<0.001).

Influence of dietary salt intake on the response of isolated perfused mesenteric veins of the dog to vasoactive agents.

Background: Previous work has established that a high dietary salt intake results in enhanced arterial vasoconstrictor responses to stimulation with agonists. This investigation was designed to investigate the effects of dietary salt on the responses of isolated capacitance vessels (third order mesenteric veins).

Methods: Dogs were fed diets containing low, intermediate, and high levels of dietary salt (0.