Author Posting. © The Physiological Society 1982. This is the author's version of the work. It is posted here by permission of Blackwell Publishing for personal use, not for redistribution. The definitive version was published in Journal of Physiology, Volume 323, January 1, 1982, pages 519-531.
Article URL: http://jp.physoc.org/cgi/content/abstract/323/1/519
NOTE: At the time of publication, the author Susan C. Opava-Stitzer was affiliated with the University of Puerto Rico School of Medicine - San Juan, Puerto Rico. Currently, April 2008, she is Dean of Research and Graduate Programs at California Polytechnic State University - San Luis Obispo.
1. The influence of ADH and the state of potassium balance on the renin-angiotensin system was studied in rats with hereditary diabetes insipidus (DI rats).
2. Plasma renin concentration in DI rats was higher than in control Long-Evans rats.
3. Spontaneous reversal of the hypokalaemia normally found in DI rats did not reduce plasma renin concentration (p.r.c.), suggesting that potassium deficiency does not contribute significantly to the elevation of p.r.c. in DI rats. Similarly, a low potassium diet failed to further increase p.r.c. in DI rats.
4. In contrast, the p.r.c. of DI rats was significantly diminished by a high potassium intake both in the presence and absence of ADH. A highly significant inverse correlation was found between p.r.c. and urinary potassium excretion in both ADH-treated and untreated DI rats on low, normal and high potassium diets.
5. Plasma renin concentration was significantly lower in ADH-treated than in untreated DI rats on a high potassium intake, suggesting that the inhibitory effects of ADH and potassium are additive.
6. ADH consistently reduced p.r.c. in DI rats independent of the state of potassium balance.
7. ADH and potassium may inhibit renin secretion via different mechanisms of action.