Responses of the renin-angiotensin system and kallikrein-kinin system to sodium and converting enzyme inhibitor (SQ 14,225)
Matthews, P.G.; Johnston, C.I.
Advances in Experimental Medicine and Biology 120b: 447-457
1979
ISSN/ISBN: 0065-2598 PMID: 390990 Document Number: 153146
Plasma renin activity, blood angiotensin I, urinary kallikrein and blood bradykinin levels have been measured concurrently in rats over a range of daily sodium intake. Plasma renin activity, blood angiotensin I levels and urinary kallikrein were significantly increased by the low sodium diet (0.02 mmole per day). Bradykinin levels did not change. Plasma renin and blood angiotensin I were closely linearly related over the range of sodium intakes. Both were associated positively with urinary kallikrein excretion. Converting enzyme inhibition caused prompt, significant changes in plasma renin activity, endogenous circulating angiotensin I, and bradykinin. The changes in circulating hormone levels were dose dependent. Blood angiotensin I levels showed a greater responsiveness than blood bradykinin levels. Plasma renin activity and blood angiotensin I levels are closely related after converting enzyme inhibition. Both increased plasma renin, and impaired clearance of angiotensin I may contribute to blood angiotensin I levels. Difference in responsiveness of blood angiotensin I and blood bradykinin levels after inhibition suggests that other independent controls of the circulating levels of these hormones exist.