Search PubMed⌕ Search

Biomedical subjects

F H Messerli

Publications and source records attributed to F H Messerli.

At least 307 records · Page 17Linked to original sources

Responsiveness of plasma aldosterone: dependency upon basal secretory activity.

The responsiveness of plasma aldosterone levels to various stimuli was evaluated in 44 normal subjects, 17 patients with mild to moderate renal failure, 30 patients with terminal renal failure, and 13 anephric subjects. Plasma aldosterone, renin activity (PRA), cortisol, sodium, and potassium levels were measured before and after one hour of upright posture (N = 191); ACTH infusions (N = 76); and angiotensin II infusion (N = 36). Plasma aldosterone responses correlated (r greater than or equal to 0.53; p less than 0.02) with basal plasma aldosterone levels during upright posture in all four groups, with ACTH infusion in all groups except anephric subjects, and with angiotensin II administration in patients with mild to moderate renal failure or patients combined. These relationships were consistently closer than those between aldosterone responses and changes in PRA or basal PRA. However, postural aldosterone responsiveness at any given basal aldosterone level was significantly lower in patients with renal disease than in normal subjects, and this was associated with a parallel impairment in renin responsiveness. In contrast, when related to basal levels aldosterone responsiveness to ACTH or angiotensin II appreared to be comparable in normal subjects and patients with renal disease. Aldosterone responses to posture, ACTH, or angiotensin II did not correlate with associated changes in plasma cortisol, sodium, or potassium levels. These data suggest that basal adrenal secretory activity is a major factor conditioning aldosterone responsiveness to various stimuli in normal subjects as well as in patients with renal disease.

Acute Kidney Injury↗

Renal artery stenosis and polycystic kidney disease.

A patient had unilateral renal artery stenosis and, at the same time, bilateral polycystic kidney disease. The renal venous renin ratio of 151:40, together with a high peripheral plasma renin activity, indicated that the hypertension was partially caused by renopressor mechanism. Correction of the obstructive lesion permitted a better control of hypertension with antihypertensive drugs, and the peripheral and renal venous renin activity returned to normal. The success in detecting one pathogenic mechanism responsible for arterial hypertension should not deter further diagnostic efforts.

Adult↗

[Increased renal prostaglandin E2 secretion in Bartter's syndrome].

In a 52-year-old patient with Bartter's syndrome, peripheral venous prostaglandin E2 (PGE2) and plasma renin activity (PRA) levels were markedly elevated and plasma aldosterone concentration (pa) was at the upper limit of normal, though inappropriately high relative to the decreased plasma and whole body potassium levels. Blood pressure, plasma volume, exchangeable body sodium, plasma cortisol and urinary catecholamines were normal. Renal venous PGE2 was two to three times higher than peripheral PGE2. Indomethacin (300 mg/day) decreased peripheral PGE2 by 50%, PRA by 84% and PA by 72%, induced a positive potassium balance (greater than 350 mEq) with normal plasma potassium levels, and returned the previously marked resistance to the pressor effect of angiotensin II to normal. During the entire study, highly significant correlations (p less than 0.001) between peripheral PGE2 and PRA (r = 0.86) or PA (r = 0.90) were found. In this patient the hyperreninemia was not related to volume depletion. These data indicate that in Bartter's syndrome renal PGE2 secretion may be increased, systemic blood levels of PGE2 may be elevated and closely related to PRA, and indomethacin ameliorates these abnormalities and improves potassium balance. These results are consistent with the ascription of an important role to excessive renal PGE2 secretion in the pathogenesis of Bartter's syndrome.

Aldosterone↗

Renal vein plasma adenosine 3',5'-cyclic monophosphate in renovascular hypertension.

The concentration of plasma adenosine 3',5'-cyclic monophosphate (cyclic AMP) and plasma renin activity (PRA) were measured concomitantly in blood from both renal veins and in arterial blood in 22 hypertensive patients. In the nine patients with true renovascular hypertension the concentration of plasma cyclic AMP was greater in the venous effluent of the kidney affected by the renal artery stenosis than in that of the unaffected or less affected kidney. The arteriovenous difference in cyclic AMP concentration was less on the affected side in all but one patient. The arteriovenous differences in PRA identified the affected kidney as the source of hyper-reninemia and showed that renin release from the other kidney was suppressed. In the 13 patients with hypertension associated with but unrelated to renal artery stenosis there were no consistent patterns of cyclic AMP concentration or PRA in the venous effluent of the kidneys or of their arteriovenous differences. In renovascular hypertension the venous effluent of the kidney affected by renal artery stenosis contains not only more renin but also more cyclic AMP, owing to either increased cyclic AMP production or decreased excretion or extraction of cyclic AMP by the affected kidney. This unilateral increase in cyclic AMP concentration may become a complementary diagnostic feature of true renovascular hypertension.

Cyclic AMP↗

Effects of angiotensin II on steroid metabolism and hepatic blood flow in man.

Metabolic clearance rates (MCR) of aldosterone, cortisol, 11-deoxycorticosterone (DOC), corticosterone, and progesterone were simultaneously measured by constant infusion in eight control subjects before and during angiotensin II infusion in subpressor (3 ng/min per kg) and pressor (22 ng/min per kg) doses. Plasma levels of aldosterone and cortisol, the heat-labile protein-bound fraction of aldosterone, and hepatic blood flow (HBF) (as estimated by the fractional clearance of indocyanine green) were determined concomitantly. Angiotensin II in a subpressor dose produced a significant decrease of the MCR of aldosterone (by 23%), cortisol (by 16%), DOC (by 26%), corticosterone (by 14%) and progesterone (by 33%). The pressor dose further decreased the respective MCR by 37%, 21%, 40%, 28%, and 42% of the baseline value. Plasma aldosterone levels rose by 317% with subpressor and by 434% with pressor doses. HBF decreased by 18% with subpressor and by 33% with pressor doses of angiotensin II. Furthermore, there were significant negative correlations between the MCR of each steroid and the respective values of the fractional clearance of indocyanine green. We conclude that angiotensin II, by its vasoconstrictive action on the splanchnic vascular bed, decreases the MCR of aldosterone, cortisol, DOC, corticosterone, and progesterone. This decrease has to be taken into account when considering the stimulatory effect of angiotensin II on various plasma steroid concentrations.

Adrenal Cortex Hormones↗

Response of several adrenal steroids to ACTH stimulation in essential hypertension.

Plasma concentrations of progesterone (P), deoxycorticosterone (DOC), 17-hydroxyprogesterone (17-OH P), corticosterone (B), deoxycortisol (S), cortisol (F), and aldosterone were measured in 8 control subjects and in 10 patients with low and normal renin essential hypertension (EH) before and 4 and 8 h after an iv infusion of 25 units of ACTH. Secretion rates of 18-hydroxy-11-deoxycorticosterone (18-OH DOC) were measured for the 24 h prior to and the day of the ACTH infusions. The hypertensive patients had significantly higher plasma levels of aldosterone, DOC and S after ACTH than the controls, whereas plasma B levels were significantly lower. The low renin subgroup considered separately had significantly higher plasma levels of aldosterone and DOC than controls, and higher levels of B and lower levels of F than the normal renin subgroup in response to ACTH. Although not significantly different, the plasma levels of P and the secretion rate of 18-OH DOC tended to be higher, and plasma 17-OH P and F levels lower after ACTH in patients with EH than in controls. The low renin subgroup tended to have the highest plasma S levels and 18-OH DOC secretory rates and lowest F levels. Estimations of adrenal 11beta-hydroxylating efficiency in response to ACTH in patients and controls by plasma steroid ratios revealed significantly lower B/DOC ratios in both low and normal renin patients compared to controls, supported by somewhat lower F/S ratios in these patients, especially those in the low renin subgroup. Altered 17-hydroxylating efficiency seen by significantly lower 17-OH P/P ratios were also found in those with EH, supported by somewhat lower F/B and S/DOC ratios in these patients, agian especially in the low renin subgroup. These data are compatible with a pattern of altered adrenocortical steroid biosynthesis in essential hypertension bearing features similar to adrenal 11beta and 17alpha-hydroxylation deficiencies.

Adrenal Cortex Hormones↗

Circadian variations of the urinary excretion of catecholamines and electrolytes.

Concomitant measurements of circadian variations in the urinary excretion of dopamine (DA), homovanillic acid (HVA), norepinephrine (NE), epinephrine (E) as well as of creatinine, sodium and potassium under controlled dietary conditions during relative physical and emotional rest in 13 volunteers have shown that maximum excretion of all these substances occurred in the afternoon period between 14:30h and 18:00h, and minimum excretion in the morning between 4:00h and 5:00h. The changes were in some cases progressive from one collection period to the other, and synchronized for NE and E. DA and HVA excretions fluctuated from subject to subject. Excretory rhythms of sodium and potassium were found to be similar to those of the catecholamines. This can be explained by diurnal changes in renal blood flow and different renal excretory mechanisms of catecholamines. None of the catecholamines correlated with the urinary volume but urinary NE and E positively correlated with urinary creatinine, urinary NE and E with urinary DA and urinary sodium with urinary E. There are some common patterns in the diurnal rhythms of catecholamines and electrolytes but their interrelationship is different for individual catecholamines.

Adult↗

Mineralocorticoid secretion in essential hypertension with normal and low plasma renin activity.

In 19 control subjects, 33 patients with essential hypertension and normal plasma renin activity (PRA) and 11 patients with low PRA, secretory rates of 18-hydroxy-11-deoxy-corticosterone (18-OH DOC), 11-deoxycorticosterone (DOC) and corticosterone were measured. Patients with low PRA were significantly older and had higher arterial pressure and slightly lower plasma potassium levels than patients with normal PRA. Mean 18-OH DOC secretion rate was higher in patients with normal PRA (603 +/- 112 SEM mug/24 hr) than in control subjects (219 +/- 19) and considerably higher (P less than 0.001) in patients with low PRA (1800 +/- 472). DOC and corticosterone secretion rates were within normal limits in most hypertensive patients. Plasma aldosterone was significantly higher in the hypertensive population than in control subjects whereas no significant difference was observed between the low- and normal-renin groups. A significant (P less than 0.01) mutual positive correlation was found between the secretion rates of 18-OH DOC, DOC and corticosterone in patients with low plasma renin activity. In contrast, there was no correlation between the secretion rates of the three mineralocorticoids in control subjects and patients with normal plasma renin activity. These data suggest a biosynthetic variation of the mineralocorticoid pathways in essential hypertension.

18-Hydroxycorticosterone↗

Plasma cyclic adenosine 3':5'-monophosphate response to isoproterenol and glucagon in hyperkinetic borderline (labile) hypertension.

The hemodynamic changes observed in patients with the "hyperkinetic" form of borderline (labile) essential hypertension (BEH) could be related to the hyperresponsiveness of cardiac beta-adrenergic receptors to catecholamines. The isoproterenol-induced increase in plasma cyclic adenosine 3':5'-monophosphate (cAMP) reflects the response of adenylate cyclase to beta-adrenergic stimulation, whereas a non-beta-receptor-mediated increase occurs with the administration of glucagon. Both substances were infused into 13 control subjects and 14 patients with the hyperkinetic form of BEH before and after propranolol administration. Baseline plasma cAMP concentrations were comparable in both groups. After 30 minutes of isoproterenol infusion (20 ng/kg per min) a significantly higher increase in plasma cAMP and heart rate and a smaller decrease in diastolic blood pressure were seen in this type of BEH than in control subjects. The increase in plasma cAMP and in heart rate correlated positively when all subjects were considered together. Propranolol abolished hemodynamic and humoral responses to a similar degree in both groups. The plasma cAMP responses to glucagon (200 ng/kg per min) were slightly lower in our patients with BEH than in control subjects and were not suppressed by propranolol. The data are compatible with a hyperreactivity of the beta-adrenergic receptors or of the adenylate cyclase or both in hyperkinetic BEH and could correspond to the previously observed exaggerated beta-adrenergic drive to the heart in this type of hypertension. The non-beta-receptor-mediated rise in plasma cAMP (glucagon), however, remains comparable in control subjects and BEH.

Adult↗

Effects of ACTH on steroid metabolism.

Metabolic clearance rates (MCR) of aldosterone, cortisol, DOC, corticosterone, and progesterone were simultaneously measured by constant infusion in 8 control subjects before and during an ACTH infusion (12.5 U/4 h). Plasma levels of aldosterone and cortisol, the heat-labile plasma protein-bound fraction of aldosterone, and hepatic blood flow as estimated by the fractional clearance of indocyanine green, were concomitantly determined. The mean MCR of aldosterone, cortisol, and DOC increased to a peak value of 26%, 23%, and 22%, respectively, above baseline values. The increase was already significant (P is less than 0.001) 30 min after the beginning of the ACTH infusion. In contrast, no consistent changes occurred in the MCR of corticosterone and progesterone or in hepatic blood flow. ACTH induced a marked fall in the heat-labile plasma protein-bound fraction of aldosterone. Plasma levels of aldosterone and corsitol increased by 190 and 250%, respectively. A significant negative correlation (r=-0.423, P is less than 0.01) between the MCR and the heat-labile protein-bound fraction of aldosterone was observed. We suggest that competitive interactions in the protein binding properties of various steroids account for the selective effect of ACTH on the MCR of aldosterone, cortisol, and DOC.

Adrenocorticotropic Hormone↗

Effects of beta-adrenergic blockade on plasma cyclic AMP and blood sugar responses to glucagon and isoproterenol in man.

In healthy humans glucagon infusion resulted in a significant increase in blood sugar and in plasma cyclic AMP. No discernible hemodynamic effects were found. Isoproterenol infusion on a mole per mole basis in the same subjects induced a significant, although less pronounced rise in plasma cyclic AMP, heart rate, and a fall in diastolic blood pressure but had no effect on blood sugar. Propranolol administration abolished the hemodynamic effects of isoproterenol and significantly decreased the response of plasma cyclic AMP; the same blocking dosage had little effect on plasma cyclic AMP changes induced by glucagon wheras the response in blood sugar was significantly reduced. These data in vivo are compatible with the in vitro demonstration of separate receptors for glucagon and isoproterenol.

Adult↗

Arterial hypertension and neurofibromatosis: renal artery stenosis and coarctation of abdominal aorta.

A 10-year-old girl had arterial hypertension, generalized neurofibromatosis, coarctation of the abdominal aorta and multiple stenoses at the origin of each renal artery. After resection of the stenotic areas and reimplantation of the renal arteries in the aorta, her arterial pressure decreased substantially. However, hypertension recurred and radiologic follow-up 4 1/2 years later showed distinct progression of the coarctation and renewed stenosis of all renal arteries at their origin. The stenotic areas showed eccentric intimal proliferation, frequently bulging into the lumen, with small nodular aggregates of smooth muscle cells and proliferation of fibrous tissue containing spindle-shaped nuclei in a palisading pattern. Hypertension associated with neurofibromatotic vascular disease has been described in 47 other patients in the literature. These patients have been young (mean age, 14 years) and predominantly male. In contrast to fibromuscular dysplasia, in which 95% of all stenoses are found in the distal two thirds of the renal arteries, in vascular neurofibromatosis more than 50% of the stenoses are found at the origin.

Adolescent↗

Hypertension with renal arterial stenosis: humoral, hemodynamic and histopathologic factors.

In 46 hypertensive patients with unilateral renal arterial stenosis, peripheral and renal venous plasma renin activity, juxtaglomerular cell count and granularity and systolic pressure gradient across the stenosis were determined. After corrective surgery and a mean postoperative observation period of 4.3 years, 18 patients were completely relieved of hypertension (good responders), 14 had a substantial reduction in arterial pressure (fair responders) and 14 remained hypertensive (poor responders). Analysis of plasma renin activity in both renal veins indicated that a ratio (stenotic/nonstenotic side) greater than 2.0 correctly predicted a favorable surgical result in all cases. Peripheral plasma renin activity was greater than normal in 65 percent of good responders, in 50 percent of fair responders and in one nonresponder. The prognostic accuracy of a pressure gradient greater than 40 mm Hg was 78 percent; no patient with a gradient of less than 40 mm Hg benefited from surgery. An increased juxtaglomerular cell count on the affected side predicted a successful operative result in 88 percent, as did increased granularity in 85 percent of cases. Renal venous renin ratio correlated positively (r =0.738, P less than 0.001) with the pressure gradient across the stenosis. The renal venous plasma renin activity of the affected side also correlated positively (r = 0.771, P less than 0.001) with the absolute count of granular cells in the juxtaglomerular apparatus. Plasma renin activity in both renal veins is the most reliable predictor of operative outcome. The addition of juxtaglomerular cell count or pressure gradient across the stenosis increases prognostic accuracy only slightly. The close mutual correlations between renal venous renin ratio, pressure gradient and juxtaglomerular cell count support the experimental evidence of a causal relation between the hemodynamic effects of the arterial lesion and the humoral and histologic changes observed in hypertension with renal arterial stenosis.

Adult↗