The Hormones of Renal Sodium Conservation Act Synergistically to Arouse a Sodium Appetite in the Rat
Central or systemic administration of angiotensin1,2,4 as well as peripheral administration of either desoxycorticosterone acetate (DOCA) or aldosterone8,9 will arouse a sodium appetite in the rat but only when large doses of the hormone are used or when negative sodium balance is induced6,7, Recently, Epstein3 has suggested that these same hormones may act in a synergistic manner at physiological concentrations, to produce a sodium appetite and that their concurrent action may underly the sodium appetite which occurs naturally in states of sodium depletion. Fluharty and Epstein5 have since supported this hypothesis by arousing a rapid and robust sodium appetite upon central administration of angiotensin II (Ang II) to sodium replete rats given subcutaneous injections of DOCA. The doses of both hormones were insufficient to arouse a sodium appetite when given alone, and the appetite occured in animals that were in positive sodium balance. We have now extended this line of investigation to the naturally occuring mineralocorticoid, aldosterone, enquiring whether it is the synergistic partner with angiotensin II in generating the appetite.
KeywordsSodium Balance Plasma Sodium Concentration Sodium Appetite Negative Sodium Balance Effective Synergist
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