The distribution of beta-adrenoceptors in dog kidney: an autoradiographic analysis.
The distribution of beta-adrenoceptors in slide-mounted dog kidney sections was determined using the radioligand (-)-[125I]cyanopindolol ((-)-[125I]CYP) and autoradiography. Using conditions designed to prevent (-)-[125I]CYP binding to non-beta-adrenoceptor sites, biochemical studies revealed that (-)-[125I]CYP binding equilibrated within 150 min (K1 = 3.2 X 10(8) M-1 min-1), was saturable (KD = 30.72 +/- 2.96 pM; Bmax = 0.57 +/- 0.03 fmol/section, n = 4) and stereoselective with respect to the stereoisomers of propranolol and pindolol. Delineation of beta-adrenoceptor subtypes with the selective beta 1-adrenoceptor antagonist betaxolol and beta 2-adrenoceptor antagonist ICI 118,551 demonstrated that the proportions of beta 1-: beta 2-adrenoceptors was between 1:6 and 1:11. Autoradiographic studies showed that beta 1-adrenoceptors were localized on the juxtaglomerular apparatus and glomeruli, while beta 2-adrenoceptors were localized on medullary rays. The distribution of beta-adrenoceptors with respect to renal function in the dog kidney is discussed.
D000319:Adrenergic beta-Antagonists; D000818:Animals; D001345:Autoradiography; D004285:Dogs; D005260:Female; D066298:In Vitro Techniques; D007457:Iodine Radioisotopes; D007668:Kidney / Q000378:metabolism*; D008297:Male; D010869:Pindolol / Q000031:analogs & derivatives; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*
D000319:Adrenergic beta-Antagonists; D007457:Iodine Radioisotopes; D011943:Receptors, Adrenergic, beta; C047975:cyanopindolol; D010869:Pindolol