Effect of Prenalterol,a β-1-Adrenoceptor Agonist,on Renin Secretion Rate in the Anaesthetized Dog

Abstract: The effects of the β-1-adrenoceptor agonist, prenalterol, 20 μg/kg intravenously on renin secretion rate (RSR), renal haemodynamics and sodium excretion were examined in anaesthetized dogs with innervated or denervated kidneys. In dogs with innervated kidneys, prenalterol increased RSR from 1.1±0.2 to 7.9±0.1 unitsXmin.^?1Xg^?1 (P<0.01). Prenalterol did not affect mean arterial pressure, renal blood blow, glomerular filtration rate or sodium excretion. Heart rate was increased by 53±17 beats/min. (P<0.01). The increase in RSR produced by prenalterol was independent of intact renal innervation as RSR increased to the same extent in dogs with denervated kidneys. Pretreatment with the β-1-adrenoceptor antagonist, metoprolol 0.5 mg/kg intravenously, abolished the increase in RSR produced by prenalterol. These findings suggest that prenalterol directly activates renal β-1-adrenoceptors to increase RSR.