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Biomedical subjects

H R Brunner

Publications and source records attributed to H R Brunner.

At least 505 records · Page 28Linked to original sources

Angiotensin II blockade in congestive heart failure.

Five of 11 normotensive patients with congestive heart failure responded to an infusion of the specific angiotensin II antagonist, saralasin, by reducing systemic vascular resistance from 2274 +/- 418 to 1690 +/- 351 dynes/sec/cm-5 (mean +/- standard error). This decrease was accompanied by a reduction in left ventricular filling pressure from 19.4 +/- 5.9 to 11.6 +/- 4.0 mm Hg, an increase in cardiac index from 2.2 +/- 0.4 to 2.7 +/- 0.4 l/min/m2 and a decrease in mean arterial pressure from 95 +/- 9.8 to 86 /+- 8.6 mm Hg. In the other 6 patients with congestive heart failure and in 4 controls, saralasin produced either no change or slight increases in systemic vascular resistance. Plasma renin activity did not differentiate responders from non-respnders. Specific inhibition of angiotensin may provide a means for reducing inappropriately high peripheral resistance in some patients with congestive heart failure.

Adult↗

Angiotensin II inhibition. Treatment of congestive cardiac failure in a high-renin hypertension.

A patient with intractable congestive cardiac failure secondary to renovascular hypertension and severe coronary artery disease was infused with the competitive antagonist of angiotensin II, saralasin acetate. The infusion produced an impressive increase in cardiac output and left ventricular stroke work index in parallel with a striking decrease in the systemic and pulmonary vascular resistance, the coronary resistance, and the myocardial oxygen consumption. It is suggested that angiotensin inhibition may present advantages over other forms of treatment of congestive cardiac failure in selected cases.

Angiotensin II↗

A specific orally active inhibitor of angiotensin-converting enzyme in man.

An orally active inhibitor of the angiotensin-converting enzyme, SQ 14,225 (D-2-methyl-3-mercaptopropanoly-L-proline), was administered to fourteen normal male volunteers to evaluate its safety and efficacy in inhibiting pressor responses to exogenous angiotensin I. SQ 14,225 produced significant blockade within 15 min of oral administration. The magnitude and duration of inhibition were dose-related. After a dose of 20 mg, complete blockade was observed for more than 2 h and partial inhibition for over 4 h. There was no effect on pressor responses to angiotensin II. SQ 14,225 promises to provide a new approach to the diagnosis and treatment of disorders involving over-activity of the renin-angiotensin system.

Administration, Oral↗

Angiotensin II blockade in normal man: interaction of renin and sodium in maintaining blood pressure.

Nine normotensive volunteers underwent six days of sodium-depletion followed by six days of sodium-repletion. On days six and twelve, the angiotensin II inhibitor, sar1-ala8-angiotensin II (saralasin), was infused i.v. and the blood pressure monitored with the subjects first in supine and then in upright position. The degree of induced sodium-depletion was varied over a considerable range in order to determine the level of sodium balance which is critical for maintaining blood pressure in the absence of the pressor action of angiotensin II. Five subjects had a cumulative sodium loss of more than 200 mEq, mainly because of more vigorous diuretic treatment; upon infusion of saralasin, four exhibited marked hypotension in the erect position. The fifth became deeply hypotensive while still supine and was unable to stand up. Hypotension occurred in spite of clinical evidence of catecholamine oversecretion. In the four patients who had urinary sodium losses of less than 200 mEq, infusion of the inhibitor did not reduce their blood pressure. Following sodium-repletion, none of the nine subjects exhibited a blood pressure response to the inhibitor. These results suggest that angiotensin II plays an active role in sustaining normal blood pressure only under conditions of considerable sodium-depletion.

Adult↗

Is elevated plasma renin activity of prognostic importance in progressive systemic sclerosis?

The pathologic lesions of the kidney in scleroderma in many respects resemble those of malignant hypertension, perhaps even in the absence of comparable blood pressure elevation. Because the malignant vascular changes have been related to hyperreninemia, we measured plasma renin activity in 23 patients with scleroderma with or without hypertension and/or renal failure. We found that high renin levels in most cases shortly preceded or coincided with a phase of sudden deterioration of the disease, characterized by a rapidly progressive renal failure. The outcome of this phase was invariably fatal, except for two patients in whom bilateral nephrectomy successfully arrested the rapid downhill course. These findings suggest that an unexplained increase in circulating renin levels in an otherwise stable patient with scleroderma may be taken as a possible marker of imminent deterioration requiring close monitoring and immediate therapeutic intervention.

Adult↗

[Angiotensin II inhibitors for the diagnosis and treatment of hypertension].

Specific antagonists of the renin angiotensin system have been used to investigate the role of this hormonal system in blood pressure homeostasis and in different types of experimental and clinical hypertension. Using this approach it was possible to show that renin via angiotensin participates actively in blood pressure maintenace, particularly following sodium depletion. Such antagonists, if available for oral administration and taken together with a diuretic, would be useful therapeutically.

Adult↗

Reciprocal relation between renin dependency and sodium dependency in essential hypertension.

To investigate the roles of angiotensin II and sodium in essential high-renin, normal-renin and low-renin hypertension, 14 patients received the competitive antagonist of angiotensin II, saralasin, during periods of sodium depletion and repletion. Blood-pressure response to saralasin was determined by the state of sodium balance. Patients from all three renin subgroups exhibited a fall in blood pressure when sufficiently sodium depleted, and an elevation in blood pressure when sodium replete or insufficiently depleted. However, those with low renin required loss of substantially more sodium (sufficient to elicit compensatory stimulation of renin) before depletion could be achieved. In patients with essential hypertension of all three renin subgroups, sodium balance determines the degree of participation of the renin-angiotensin system in sustaining high blood pressure. Even the low-renin type can become renin dependent with sufficient sodium depletion.

Adult↗

Determination of renin-dependency and sodium-dependency in the three renin sub-groups of essential hypertension.

1. In all three renin sub-groups of essential hypertension, the state of sodium balance determines the degree of participation of the renin-angiotensin system in sustaining high blood pressure. 2. Even the low-renin type can become renin-dependent when sufficient sodium depletion has bee achieved. 3. The main difference between patients of these sub-groups appears to be their variable capacity to become depleted of sodium under standard dietary regimens.

Aldosterone↗

Angiotensin II blockade in normal man and patients with essential hypertension. Blood pressure effects depending on renin and sodium balance.

1) Saralasin was administered to 9 normotensive volunteers and 13 patients with essential hypertension after sodium depletion and sodium repletion. 2) In standing normotensive volunteers, angiotensin II inhibition induced significant hypotension if previously a cumulative sodium loss of at least 160-200 mEq had been induced. 3) In patients with essential hypertension, saralasin infusion induced either blood pressure reduction, no change or even significant blood pressure increase, depending on the prevailing state of sodium balance. 4) Following vigorous and prolonged sodium depletion induced by low sodium diet, with chlorthalidone and spironolactone, blood pressure became renin-dependent even in those patients who initially had exhibited a hypertensive response to saralasin, suggesting that under appropriate conditions, renin can play an active pressure role in all patients with essential hypertension. 5) Saralasin administration to patients with essential hypertension may not only be useful for recognizing renin dependency but may also, via the slight intrinsic agonistic effect of the compound, permit identification of overactivity of the sodium factor.

Adult↗

Reciprocation of renin dependency with sodium volume dependency in renal hypertension.

An angiotensin II inhibitor was administered to rats with two-kidney Goldblatt hypertension. The inhibitor produced a marked drop in blood pressure after 5 weeks but no significant change after 15 weeks of hypertension. However, even after 15 weeks of hypertension, following sodium depletion by either diuretics or a low sodium diet, the animals again became renin dependent as readministration of the inhibitor induced a significant fall in blood pressure. The data indicate that two-kidney Goldblatt hypertension is initially renin dependent but subsequently becomes sodium volume dependent in a way similar, although more protracted, to that already described for one-kidney Goldblatt hypertension.

Angiotensin II↗