Polyuria, polydypsia, and hypertension produced by a six-day intravenous infusion of prostaglandin E1 in the conscious dog.

Abstract

The effects of a continuous intravenous infusion of prostaglandin E1 (PGE1) on mean arterial pressure (MAP), sodium and water balance, and plasma renin activity (PRA) were examined in 10 conscious dogs maintained on a 70 to 75 mEq/day sodium intake. In a crossover pattern, each dog received 6 days of intravenous PGE1 (0.1 micrograms/kg/min) and 6 days of intravenous diluent. When compared to diluent, intravenous PGE1 resulted in a mild sustained rise in MAP. By Day 6 the intravenous PGE1, MAP had increased from 98 +/- 4 to 112 +/- 5 mm Hg (mean +/- SE) (p less than 0.04). Concurrent with the MAP increase, PRA increased from 0.6 +/- 0.2 to 3.1 +/- 0.7 ng angiotensin I (AI)/ml/hr (p less than 0.03). To assess the role of the renin-angiotensin system in the maintenance of the systemic hypertension. AI converting-enzyme inhibitor was given to four dogs on Day 6 of both intravenous PGE1 and diluent. Only when the dogs were receiving PGE1 did the administration of converting-enzyme inhibitor result in a significant decrease in MAP (-19 +/- 5 mm Hg). In addition to increasing arterial pressure, the chronic infusion of PGE1 also produced changes in salt and water balance. When compared to diluent, PGE1 resulted in a twofold increase in both water intake and urine output, an increase in urinary sodium excretion (from 72 +/- 3 to 84 +/- 6 mEq/day, p less than 0.05, on Day 1), and a decrease in urine osmolality (from 942 +/- 82 to 586 +/- 61 mOsmol/kg H2O/day, p less than 0.05, on Day 1).(ABSTRACT TRUNCATED AT 250 WORDS)