Decreased cardiac beta-adrenergic receptors in deoxycorticosterone-salt and renal hypertensive rats.
The development of experimental deoxycorticosterone-salt (DOCA-salt) and renal artery clip hypertension in rats is associated with alterations in the sensitivity of the myocardium to adrenergic stimulation. We studied beta-adrenergic receptors and isoproterenol-stimulated adenylate cyclase in myocardial membranes from hypertensive rats to determine whether this altered sensitivity is associated with any change in beta-adrenergic receptors. The specific binding of the beta-adrenergic antagonist, 125I-iodohydroxybenzylpindolol, was used to measure numbers and affinities of receptors in myocardial membrane preparations. Cardiac membranes from both DOCA-salt and renal hypertensive rats showed significantly fewer beta-receptors than did membranes from control, normotensive rats. Receptor affinity remained unchanged. This decrease was from 110 +/- 19 to 49 +/- 5 fmol/mg protein for DOCA-salt hypertension and from 110 +/- 18 to 75 +/- 16 fmol/mg protein for renal artery clip hypertension. Isoproterenol-stimulated adenylate cyclase activity also was lower in membranes from hypertensive rats, whereas basal and fluoride-stimulated activities were unchanged.
D009597:4-Nitrophenylphosphatase / Q000378:metabolism; D000818:Animals; D002462:Cell Membrane / Q000032:analysis / Q000378:metabolism; D002499:Centrifugation, Density Gradient; D003900:Desoxycorticosterone; D004195:Disease Models, Animal; D005260:Female; D006321:Heart / Q000294:innervation*; D006973:Hypertension / Q000139:chemically induced / Q000378:metabolism* / Q000503:physiopathology; D006977:Hypertension, Renal / Q000378:metabolism*; D006978:Hypertension, Renovascular / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D009206:Myocardium / Q000032:analysis / Q000201:enzymology; D009708:Nucleotidases / Q000378:metabolism; D051381:Rats; D011941:Receptors, Adrenergic / Q000378:metabolism*; D011943:Receptors, Adrenergic, beta / Q000032:analysis / Q000378:metabolism*; D012965:Sodium Chloride; D013564:Sympathetic Nervous System / Q000503:physiopathology*
D011941:Receptors, Adrenergic; D011943:Receptors, Adrenergic, beta; D003900:Desoxycorticosterone; D012965:Sodium Chloride; D009708:Nucleotidases; D009597:4-Nitrophenylphosphatase