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Biomedical subjects

J C Dormois

Publications and source records attributed to J C Dormois.

5 recordsLinked to original sources

Effect of furosemide on the renal excretion of digoxin.

Digoxin serum and urine levels were determined by radioimmunoassay in 6 subjects (4 patients with heart disease and 2 volunteers without heart disease) who had been maintained on oral digoxin (0.25 or 0.5 mg daily). Observations were made during a 3-day control period and then during 8 days of concomitant digoxin and oral furosemide (40 mg daily) therapy. Serum digoxin levels determined 10 and 24 hr after each dose of digoxin averaged 1.2+/-0.1 ng/ml (M+/-SE) during control and 1.3+/-0.1 during the last 3 days on digoxin and furosemide. The daily urinary excretion of digoxine averaged 51+/-6% of the oral dose during control and 52+/-6 during the entire period of furosemide administration. The renal clearance of digoxin and creatinine averaged 94+/-7 and 87+/-11 ml/min, respectively, during control; corresponding values were 88+/-8 and 85+/-9 for urine collections demonstrating a distinct diuretic effect of furosemide and 87+/-8 and 75+/-10 for urine collections not demonstrating such an effect during diuretic therapy. The results suggest that the diuretic effect of furosemide does not significantly affect the excretion of digoxin

Adult↗

Suppression of plasma renin activity by indomethacin in man.

The effect of indomethacin or placebo on aldosterone, plasma renin activity (PRA), sodium excretion, and urinary prostaglandin (PG) levels was investigated in five hypertensive subjects in 100 mEq sodium balance who had experienced malignant hypertension with a disturbance of their renin-aldosterone relationship in the past. Indomethacin significantly lowered aldosterone levels by 43%, PRA by 58%, 24-hour sodium excretion by 49%, and urinary PG excretion, an indicator of renal PG synthesis, by 67%. Angiotensin infusion increased aldosterone to the same level before and after treatment with indomethacin. Similarly, in normal subjects in 150 mEq sodium balance, indomethacin lowered PRA by 47%; sodium excretion fell by 33%, and urinary prostaglandin E (PGE) excretion, by 55%. The acute elevation in PRA 10 minutes after intravenous furosemide was completely abolished by indomethacin. Five subjects with essential hypertension were classified as normal renin hypertensives according to their response to orally administered furosemide. Indomethacin pretreatment resulted in 60% reduction of PRA following furosemide, and three of these subjects now fell into the low renin category. Studies in vitro demonstrated that indomethacin has no effect on the renin-renin substrate interaction. Thus, indomethacin lowers PRA concomitantly with a reduction in renal PG synthetase activity. Whether indomethacin inhibits renin release by an intrarenal, PG-related mechanism or secondarily via sodium retention is discussed.

Adult↗

Plasma renin activity and plasma aldosterone during the normal menstrual cycle.

Six normal women were studied under metabolic balance conditions during the menstrual cycle. Plasma renin activity (PRA) and plasma aldosterone were estimated throughout the cycle under standardized, uniform conditions with sensitive radioimmunoassays. There is a linear increase in PRA and plasma aldosterone during the luteal phase of the cycle provided ovulation occurs. If ovulation fails, no rise is seen in either parameter. Thus, a functioning corpus luteum seems to be essential for the production of these hormonal changes.

Adult↗

Minoxidil in severe hypertension: value when conventional drugs have failed.

Twenty-six patients were selected for treatment with minoxidil on the basis of hypertension which could not be controlled either because of (1) drug failures and/or (2) side effects of drugs. Sixteen out of the 26 had had one or more previous episodes of malignant hypertension. Reduced renal function was present in the majority; eight patients were on dialysis. Average preminoxidil blood pressure was 202/127 mm. Hg supine and 162/106 upright which fell to 154/87 supine and 143/86 upright after minoxidil. Propranolol or methyldopa was given to control the reflex increase in heart rate. Edema and congestive heart failure refractory to large doses of potent diuretics necessitated discontinuation of the drug in two patients. Minoxidil proved highly efficacious regardless of initial level of blood pressure, etiology, or supine or upright posture.

Adult↗