Effects of Mineralocorticoids, Altered Sodium Intake, and Adrenalectomy on Urinary Kallikrein in Rats

Abstract

The urinary excretion of kallikrein was examined in rats whose mineralocorticoid level was increased by the administration of deoxycorticosterone or a low-sodium diet and decreased by adrenalectomy. Administration of deoxycorticosterone by injection or by subcutaneous implantation of pellets resulted in a threefold increase in kallikrein excretion after 10-30 days ( P <0.01). Low-sodium intake produced a twofold increase in kallikrein excretion after 2 and 4 weeks ( P <0.01). Urine volume and blood pressure were normal and unchanged throughout the study. Sodium excretion was unaltered by deoxycorticosterone but was essentially zero during low-sodium intake. Adrenalectomized rats excreted less than half the kallikrein of shamoperated control rats ( P <0.01). These data show a direct relationship between mineralocorticoids and kallikrein excretion and suggest that mineralocorticoids are a primary factor regulating the urinary excretion of kallikrein in rats.