A study of the beta-adrenergic receptors in rat kidnevs.

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 mug 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 mug 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 mug of (+/-)-isoprenaline.