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Biomedical subjects

H R Brunner

Publications and source records attributed to H R Brunner.

At least 487 records · Page 27Linked to original sources
PubMed1979

Oral angiotensin-converting enzyme inhibitor in long-term treatment of hypertensive patients.

The antihypertensive effect of the orally active angiotensin-converting enzyme inhibitor captopril (SQ 14225) was assessed in 22 hypertensive patients of whom 17 were followed for periods ranging from 1 to 7 months. Of these, eight had essential hypertension, eight had renovascular hypertension, and six had hypertension associated with chronic renal failure. Blood pressure decreased markedly in all patients, including those with low renin levels. Nevertheless, the magnitude of blood pressure reduction correlated with the base-line plasma renin activity (r = 0.58, P less than 0.01). Increasing the dose of captopril from 25 to 200 mg did not enhance the amplitude of the antihypertensive effect but did increase its duration. Patients' blood pressure remained well controlled and free of side-effects with a maximal daily dose of up to 200 mg by mouth twice daily. Despite the blood pressure reduction, sodium excretion tended to increase, probably because of reduced aldosterone secretion. There was no evidence of orthostatic hypotension, and no escape from the antihypertensive effect was observed. These results indicate that chronic inhibition of the angiotensin-converting enzyme with an orally active compound offers a new, efficient, and well-tolerated approach to the treatment of hypertension.

Adult↗
PubMed1979

Converting enzyme inhibition in hypertensive emergencies.

The diagnostic and therapeutic value of the angiotensin converting enzyme inhibitor teprotide (SQ 20881) was assessed in 18 patients with hypertensive emergencies. Mean blood pressure fell 31 +/- 18 mm Hg in the 10 subjects who responded to 1 mg/kg body weight administered intravenously, whereas it fell 5 +/- 3 mm Hg in the eight nonresponders. In patients who had received no previous drug treatment, log baseline plasma renin activity and change in mean blood pressure after SQ 20881 correlated significantly (r = 0.651, P less than 0.05). After acute therapy with SQ 20881, the patients who had a satisfactory response to the drug were treated with propranolol and a relatively normal sodium intake (88 meq/day). Nonresponders were treated with diuretics and sodium restriction (10 meq/day), and intermediate responders were given combination therapy. Mean blood pressure responded favorably within 24 h to the chosen regimen for each group from 152 +/- 47 to 102 +/- 31 mm Hg. SQ 20881 allows prompt evaluation of the role of renin in hypertensive emergencies and permits early choice of appropriate therapy based on the prevailing mechanism.

Adult↗
PubMed1979

Captopril and salt subtraction to treat "uncontrollable" hypertension in haemodialysis patients.

Eight patients on chronic haemodialysis for six months to 7 years with hypertension resistant to ultrafiltration and antihypertensive therapy, received Captopril (SQ 14, 225) an orally active inhibitor of converting enzyme. With this therapy, blood pressure was controlled in the 4 patients with the highest plasma renin activity. In the other 4, this treatment had to be supplemented with "isovolumetric salt subtraction", i.e. following conventional dialysis, 1-2 litres of ultrafiltrate were replaced by an equal volume of 5% glucose. The slight hyponatraemia induced by this procedure (plasma sodium 128mmol/L) was well tolerated. This procedure allows the removal of an excess of body sodium and seems to be effective even when conventional ultrafiltration during dialysis has failed. Administration of Captopril either alone or combined with "isovolumetric salt subtraction" induced good control of blood pressure in all 8 patients.

Adolescent↗
PubMed1979

Antihypertensive action of beta-adrenoceptor blockade and the renin-angiotensin system.

1 The regulation of renin secretion is mediated by way of adrenoceptors. The role of alpha-adrenoceptors remains controversial, whereas it is generally accepted that activation of beta-adrenoceptors stimulates renin and their blockade suppresses renin. 2 Although experimental renin regulation appears to be a beta 2-receptor function, clinical studies suggest that in man it is a beta 1 effect. 3 beta-Adrenoceptor-blocking agents are effective antihypertensive agents, but have variable effects on renin secretion; this variability may be attributable to different degrees of instrinsic partial beta-agonistic activity and/or different receptor or organ selectivity of various compounds. 4 Antihypertensive effectiveness seems unrelated in magnitude or timing to the baseline levels or the changes of plasma renin activity for the majority of beta-adrenoceptor-blocking drugs.

Adrenergic beta-Antagonists↗
PubMed1978

[Long-term minoxidil therapy: renin, aldosterone, noradrenaline and the need for beta blockers].

Minoxidil-induced sequential changes in plasma renin activity, urinary aldosterone and norepinephrine excretion were assessed in 11 patients with severe hypertension receiving propranolol or oxprenolol, chlorthalidone and spironolactone. Blood pressure with this treatment alone averaged 175 +/- 7/114+/-4 mm Hg (mean +/- SEM). Addition of minoxidil in a dose of 5 to 35 mg/day (mean 16 mg/day) reduced blood pressure within one week to 125+/-5/87+/-3 mm Hg. Plasma renin, urinary aldosterone and norepinephrine increased two- to threefold initially, but returned to baseline within two weeks and remained unchanged during a mean follow-up of 6.8 months. In 6 patients beta-blocking drugs were then progressively reduced and withdrawn without adverse effects, though blood pressure and heart rate increased slightly in 5 patients who required readministration of minimal doses of beta-blockers. Neither renin nor urinary aldosterone or norepinephrine excretion changed significantly after discontinuation of beta-blockade. Thus, the stimulating effect of minoxidil on renin, aldosterone and norepinephrine secretion lasts less than 3 weeks. With long-term minoxidil treatment the need for beta-blockade is markedly reduced, and these drugs may even become unnecessary in some patients.

Adult↗
PubMed1978

Innappropriate renin secretion unmasked by captopril (SQ 14 225) in hypertension of chronic renal failure.

Captopril (SQ 14 225), an orally active inhibitor of angiotensin-converting enzyme, was given to 7 hypertensive patients with chronic renal failure whose plasma-creatinine ranged from 1.5--7.4 mg/dl; whose plasma-renin activity was normal; whose hypertension was not controlled by previous therapy consisting in 5 patients of three or more antihypertensive drugs; and whose blood-pressures averaged 176/111 +/- 11/3 mm Hg. Inhibition of converting enzyme by oral captopril, 200 mg twice daily, reduced blood-pressure to 156/100 +/- 9/5 mm Hg. 5 patients needed additional treatment by frusemide 40--250 mg/day orally. With this combined regimen the blood-pressure of all patients averaged 126/85 +/- 4/3 mm Hg after 8 +/- 2 weeks of captopril. The drug was well tolerated. These results suggest that inhibition of angiotensin-converting enzyme with or without sodium depletion is an efficient treatment for hypertension associated with chronic renal failure. It appears that although renin levels in patients with this condition may be "normal", they are inappropriate in relation to the subtle degree of sodium retention that occurs with this disorder.

Administration, Oral↗
PubMed1978

Need for beta-blockade in hypertension reduced with long-term minoxidil.

Sequential changes in plasma renin activity and urinary aldosterone and noradrenaline were assessed in eight patients with severe hypertension after minoxidil had been added to their treatment. Doses of 2.5--27.5 (mean 12.5) mg/day reduced the mean blood pressure from 166/113 +/-6/2 mm Hg to 124/88+/-4/2 mm Hg in one week. Plasma renin activity and urinary aldosterone and noradrenaline increased twofold to threefold initially but returned to baseline values within two to three weeks and remained unchanged during a mean follow-up of 5.1 months. Beta-blocking drugs were then withdrawn slowly in six patients without adverse effects, though blood pressure and heart rate increased in three patients, who required minimal doses of beta-blockers. Plasma renin activity and urinary aldosterone and noradrenaline did not change significantly after beta-blockade had been stopped. We conclude that the need for beta-blockade is greatly reduced with long-term minoxidil treatment and that it may be unnecessary in some patients.

Adrenergic beta-Antagonists↗
PubMed1978

Antihypertensive effect of the oral angiotensin converting-enzyme inhibitor SQ 14225 in man.

We investigated the antihypertensive effect of the angiotensin converting-enzyme inhibitor SQ 14225 in 12 hypertensive patients for periods of three to 24 weeks. Blood pressure decreased in all patients (from 177 +/- 8/110 +/- 2 to 136 +/- 6/88 +/- 2 mm Hg--mean +/- S.E.); oral doses ranged from 400 to 1000 mg daily. Concomitant effects noted were small increases in plasma potassium concentration and pulse rate. One patient experienced a transient febrile reaction. Plasma renin activity rose during treatment, plasma aldosterone decreased, and angiotensin-converting-enzyme activity was virtually eliminated. There was no significant correlation between pretreatment plasma renin activity and degree of blood-pressure fall with SQ 14225. The exact mechanisms contributing to the blood-pressure-lowering effect of this agent remain unclear. SQ 14225 is a promising new antihypertensive agent, effective in patients refractory to traditional medical therapy.

Administration, Oral↗
PubMed1978

[Prevention of myocardial infarct?].

Myocardial infarction remains one of the leading causes of mortality and morbidity in spite of the medical and surgical therapy currently available. Only the prevention of coronary atherosclerosis seems likely to modify this situation. Epidemiological studies have established hypertension, hypercholesterolemia and cigarette smoking, among others, as risk factors. Based on these findings, it was hypothesized that control of these factors might diminish the risk. This hypothesis has been tested in man repeatedly over the past twenty years. Except as regards cigarette smoking, the results of the studies are ambiguous. Before advising the general public on measures of prevention, more data on the etiology of atherosclerosis are needed.

Arteriosclerosis↗
PubMed1978

Mechanism of blood pressure reduction by teprotide (SQ 20881) in rats.

The mechanism by which the angiotensin converting enzyme inhibitor, teprotide (SQ 20881), lowers blood pressure was assessed in anesthetized normotensive and spontaneously hypertensive (SHR) rats. Teprotide always was administered at a maximally effective dose of 1 mg/kg. In six normal Wistar rats, teprotide lowered blood pressure only after sodium depletion, an effect which was abolished by bilateral nephrectomy. Saralasin infusion (5 microgram/kg/min) into salt-depleted normal rats induced a blood pressure effect similar to that of teprotide. When administered in addition to saralasin infusion, teprotide did not reduce blood pressure further in normal rats or in SHR. When blood pressure of normal rats was raised by angiotensin II infusion (200 ng/kg/min), teprotide did not affect the induced blood pressure increase. In contrast, the pressure rise induced by angiotensin I infusion (230 ng/kg/min) was reversed by saralasin, but again concomitant administration of teprotide did not induce further blood pressure reduction. Thus, under the particular conditions of the present study, teprotide did not appear to exert its hypotensive effect by any mechanism other than inhibition of the renin-angiotensin system. Furthermore, given at a maximally effective dose to the rat, it produced no greater vasodepressor effect than did saralasin.

Angiotensin I↗
PubMed1978

Redistribution of regional blood flow after administration of saralasin in salt-depleted dogs.

1. Salt depletion was produced in five dogs by a low salt diet and daily administration of frusemide for 5 days; a control group of five dogs was placed on the same diet, to which 2.5 g of sodium chloride was added. 2. Saralasin infusion (0.5 microgram min-1 kg-1) reduced mean aortic blood pressure and total peripheral vascular resistance and increased cardiac output in salt-depleted dogs, but did not affect the heart rate and left ventricular dP/dt. 3. Saralasin infusion increased mean aortic blood pressure slightly in normal dogs; other systemic haemodynamic parameters did not change significantly. 4. Saralasin decreased hepatic arterial flow in both normal and salt-depleted dogs, but increased blood flow to left ventricle and kidneys only in salt-depleted dogs. 5. These results suggest that saralasin exerts a partial agonist effect in normal dogs to increase arterial blood pressure, but causes a depressor response during salt depletion because it reverses the vasoconstrictor effect of angiotensin II, particularly on the renal and coronary circulations.

Angiotensin II↗
PubMed1978

Long-term treatment of hypertension in man by an orally active angiotensin-converting enzyme inhibitor.

1. Captopril or SQ 14 225, administered orally twice a day, reduced the blood pressure of hypertensive patients whatever their clinical diagnosis and even when their plasma renin activity was 'normal' or low. 2. Long-term administration of captopril, either alone or together with diuretics, provides a powerful new tool with which to treat ambulatory hypertensive patients. 3. The renin system may play an important role in maintaining blood pressure in a majority of hypertensive patients.

Adult↗
PubMed1978

Congestive heart failure in normotensive man. Haemodynamics, renin, and angiotensin II blockade.

The role of the renin angiotensin system was evaluated in 18 normotensive patients with chronic congestive heart failure and in 5 controls. No correlation was observed between plasma renin activity and cardiac index. There was a significant inverse correlation between renin and pulmonary capillary wedge pressure (r = -0.61, P less than 0.01). Renin values of the patients appeared to be increased when compared with controls with similar left ventricular filling pressure. Specific angiotensin II inhibition by saralasin decreased arterial pressure in 8 out of 14 patients: their renin was significantly higher than that of the remaining 6 patients (P less than 0.01). The 2 patients with the lowest renin levels responded to saralasin with a blood pressure increase. Left ventricular filling pressure decreased in all but these latter 2 patients with either little change or an increase in stroke volume. Thus, renin levels appear to be increased in normotensive patients with congestive heart failure when related to left ventricular filling pressure. Renin via angiotensin II plays a role in the blood pressure control of many patients with congestive heart failure. In some patients angiotensin II blockade appears to improve cardiac function by unloading the left ventricle.

Adult↗
PubMed1978

Angiotensin converting enzyme inhibition in patients with congestive heart failure.

The etiology of afterload elevation in congestive cardiac failure is unclear, but experimental evidence suggests a role for the renin-angiotensin system in maintaining elevated peripheral vascular resistance. The angiotensin converting enzyme inhibitor SQ20,881 was administered to eight patients with congestive cardiac failure (four hypertensives, four normotensives) during or one day after diagnostic cardiac catheterization. Various hemodynamic measurements performed before and during blockade indicate that this agent caused improvement in cardiac function in all patients by decreasing afterload. This improvement correlated with the decrease in total vascular resistance but was independent of the baseline blood pressure and plasma renin activity. These results suggest that inhibition of angiotensin converting enzyme is a worthwhile approach to the treatment of congestive heart failure, although its exact mechanism of action remains unclear.

Aged↗