Further Studies of the Mineralocorticoid Activity of 19-oxo-Deoxycorticosterone*

Abstract

Antinatriuretic and kaliuretic activities of 19-oxo-deoxycorticosterone (19-oxo-DOC) were measured in male adrenalectomized rats and compared with those of aldosterone. No significant effects of 19-oxo-DOC or aldosterone were observed in the lag period (i.e. the first hour post injection). In the subsequent 2 h, rats injected with 25 micrograms 19-oxo-DOC excreted less than half the sodium and more than twice the potassium compared to rats injected with vehicle alone. Overall mineralocorticoid activity (based on changes in urinary Na+/K+), antinatriuretic activity (based on changes in urinary Na+/creatinine) and kaliuretic activity (based on changes in urinary K+/creatinine) of 19-oxo-DOC were all in the range of 1:100th-1:200th that of aldosterone. These results are not in agreement with a recent report suggesting that 19-oxo-DOC possesses antinatriuretic activity but no kaliuretic activity.