Effects of Aldosterone on the Urinary Excretion of Total and Non-Dialyzable Hydroxyproline[1]

Abstract

In order to explore the role of mineralocorticoids on collagen metabolism, the effects of aldosterone on the urinary excretion of total and non dialyzable hydroxyproline (HYPRO) was studied in rats.

The administration of aldosterone in sesame oil, 75 µg/100g body weight to adrenalectomized rats maintained on 1% NaCl solution as drinking fluid and 1 mg of cortisone subcutaneously daily, provoked elevation of total and non dialyzable HYPRO in urine (P<0.001), when compared to similarly treated adrenalectomized rats receiving sesame oil but no aldosterone. Both groups showed a normal growth curve and had similar urinary excretion of creatinine.

The effects of aldosterone are opposed to the known lowering effects of glucocorticoids on HYPRO excretion and may suggest an effect of aldosterone on collagen turnover. Alternatively, aldosterone may modify the metabolism or excretion of HYPRO in an opposite manner to that of glucocorticoids.

Key words

Aldosterone - Hydroxyproline Excretion and Collagen

1 Supported in part by institutional funds of the Veterans Administration Hospital and Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, and University of Tennessee Center for the Health Sciences, General Research Support Grant-USPHS GR RR 05423 and through resources of the General Clinical Research Center Grant RR 00211.

1 Supported in part by institutional funds of the Veterans Administration Hospital and Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, and University of Tennessee Center for the Health Sciences, General Research Support Grant-USPHS GR RR 05423 and through resources of the General Clinical Research Center Grant RR 00211.

2 Clinical Investigator, Veterans Administration Hospital, Oklahoma City, Oklahoma. Present address: Department of Medicine, 951 Court Avenue, Memphis, Tennessee 38163