The patient's age has great impact on the development of hypertension, its duration, and severity. In patients with essential hypertension, sympathetic cardiovascular control changes from an early phase with increased beta-adrenoceptor-mediated responses, e.g., cardiac output and renin, into a later phase where these responses are blunted and alpha-adrenoceptor-mediated vasoconstriction prevail...

Result: The study involved 144 patients. Eighty four (58.3%) patients were male and 60(41.7%) patients were female with an age range of 18-78 years and a mean age of 43.5 +/13 SD. Twenty four (16.7%) patients were less than 30 years old, 107(74.3%) patients were between 31-60 years and 13(9%) patients were more than 61 years. Twenty two (15.3%) patients were black and 122(84.7%) were white. Nin...

An age-dependent study of plasma renin activity (PRA), kidney renin activity (KRA), and plasma renin substrate was carried out in rats with spontaneous hypertension during the prehypertensive, the early hypertensive, and the established hypertensive phases of their disease. PRA and KRA were both significantly elevated before and during the initial phase of hypertension and normal or subnormal d...

Modern antihypertensive therapy is enriched by an explosion in drug development that makes available increasingly specific agents whose effects have advanced our understanding of pressor mechanisms. This and other research into hypertensive mechanisms has defined the clinical, pharmacological, and endocrinologic heterogeneity of human hypertension. The sum of these developments is a greatly enh...

We have previously reported that 1) selective dietary sodium loading (without chloride) does not produce hypertension in rats of the Dahl salt-sensitive strain (DS) and 2) selective chloride loading (without sodium) lowers plasma renin activity in the intact Sprague-Dawley rat maintained on a low NaCl diet. The present study examined the effect of selective dietary chloride loading on two model...

Angiotensin II was infused at rates varying from 0.1 to 10 ng/kg per minute into 49 subjects with hypertension and 26 normotensive subjects and changes in blood pressure, plasma angiotensin II, and plasma renin activity (PRA) were determined after 20 and 30 minutes at each dose. Similar dose-related increases in angiotensin II and blood pressure occurred with a threshold of 1 ng/kg per minute i...

The development of renovascular hypertension depends on the release of renin from the juxtaglomerular (JG) cells, a process regulated by intracellular cAMP. Hydrogen sulfide (H2S) downregulates cAMP production in some cell types by inhibiting adenylyl cyclase, suggesting the possibility that it may modulate renin release. Here, we investigated the effect of H2S on plasma renin activity and BP i...

At least half of primary autonomic failure patients exhibit supine hypertension, despite profound impairments in sympathetic activity. Although the mechanisms underlying this hypertension are unknown, plasma renin activity is often undetectable, suggesting renin-angiotensin (Ang) pathways are not involved. However, because aldosterone levels are preserved, we tested the hypothesis that Ang II i...

The interrelationships of arterial pressure, plasma volume (PV), and plasma renin activity were studied in 152 consecutive male patients with uncomplicated essential hypertension. Of these, 22 (17 white and 5 black) subjects had normal plasma volumes and because of the small number were not included in the analysis of results. The remaining 130 (35 black and 95 white) patients were classified a...

Method of Blood Collection May Explain the Suppression of Plasma Renin Concentration in Prorenin Transgenic Mice To the Editor: Mercure et al1 reported the targeted expression of mouse prorenin to the liver of mice. Liver expression of mouse prorenin was under the control of the transthyretin gene promoter, and plasma prorenin levels of these TTRmProren transgenic mice were increased by 13to 28...