VAST AND APPARENTLY PARADOXICAL CONTINUOUS RISE IN PLASMA RENIN AFTER REMOVAL OF GENTLY MANIPULATED SUBMAXILLARY GLANDS IN NEPHRECTOMIZED MICE

Abstract

Gentle manipulation of the submaxillary glands of previously nephrectomized mice results in a vast increase in plasma renin concentration. The concentration reaches 1 to 7 Goldblatt units renin/ml, which is 1000-fold higher than normal plasma concentrations. The rise is much less pronounced if the glands are removed after the manipulation, confirming the site of the release. An apparent paradox is seen: the renin concentration continues to rise even after removal of submaxillary glands and kidneys, indicating that a bound form of renin is also released. The bound renin can be in the form of exocytosed granules and/or in the form of prorenin, the renin of which is activated with time. In spite of the very high renin concentrations the blood pressure is normal or only moderately increased. This disproportion between plasma renin and blood pressure can be caused by a simultaneous release of submaxillary kallikrein and renin, which have counteracting effects on the blood pressure.