A STUDY OF THE β‐ADRENERGIC RECEPTORS IN RAT KIDNEYS

Abstract
Dichloroisoprenaline (1 mg), injected intramuscularly into the rat, retarded the elimination of water and retained sodium, depressing both glomerular filtration rate and renal blood flow. A dose of 4 mg had a similar but more intense action. These actions of dichloroisoprenaline resembled those of 2 or 4 μg of (±)-isoprenaline given subcutaneously. Dichloroisoprenaline and (±)-isoprenaline summed in salt retaining effect but competed in renal vascular action. 2-Isopropylamino-1-naphth-2′*ylethanol hydrochloride (nethalide, 1 mg intramuscularly) was without action during water diuresis. A dose of 4 mg inhibited solely the excretion of water. Nethalide (1 mg) completely antagonized the antidiuretic and vascular actions of 2 μg of (±)-isoprenaline; antagonism of the salt retention caused by (±)-isoprenaline was less complete. A dose of 4 mg of nethalide antagonized both the salt retaining and the vascular actions of 4 μg of (±)-isoprenaline.