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Biomedical subjects

J W Barr

Publications and source records attributed to J W Barr.

22 records · Page 2Linked to original sources
PubMedDate not supplied

Effect of probenecid on the natriuresis and renin release induced by bumetanide in man.

In a randomized crossover trial in six normal male subjects, the effect of pretreatment with probenecid on natriuresis and renin release in response to bumetanide was studied. The subjects received 120 mEq sodium and 80 mEq potassium per day. A single dose of 2 mg bumetanide was administered on the fourth morning after pretreatment with either placebo or probenecid. Creatinine and uric acid were measured in serum and urine, plasma renin activity was determined by radioimmunoassay of angiotensin I, and plasma and urine concentrations of bumetanide were measured by a highly sensitive radioimmunoassay method. Probenecid reduced both natriuresis and hyperreninemia induced by bumetanide. This effect is postulated to be due not to a direct action on sodium excretion but is probably secondary to inhibition of renal tubular secretion of bumetanide. Consequently, these findings appear to support the concept that the quantity of bumetanide delivered to the tubular lumen is an important determinant of its diuretic effect.

Adult↗
PubMedDate not supplied

Vasopressin and hepatic artery. Effect of selective celiac infusion of vasopressin on the hepatic artery flow.

Electromagnetic flow measurement study was performed in 20 anesthetized dogs to evaluate the effect of selective celiac infusion of vasopressin on the hepatic arterial vasculature. Teh hepatic arterial flow showed a biphasic response with an initial decrease followed by a substantial increase in spite of a continued infusion. The left gastric, splenic, and superior mesentric arteries showed a monophasic response with persistent decrease of flow during the whole infusion. The biphasic response of the hepatic arterial flow is thought to be due to autoregulatory dilative action of the liver to a decrease of the portal flow. The results and previous clinical experience suggest that the selective infusions of vasopressin into arteries supplying the liver can be used for short-term vasoconstrictive therapy of acute gastrointestinal bleeding in patients without liver damage. Further experience is necessary to evaluate the safety of prolonged hepatic infusions in patients with liver damage.

Animals↗