[Myocardial beta adrenergic receptors in experimental renal hypertension, type Goldblatt II].
Properties of cardiac beta-adrenergic receptors from two kidney-one clip hypertension and control rats were studied to determine whether or not alterations in the receptor contribute to the decreased responsiveness of two kidney-one clip rat hearts to adrenergic stimulation. The number and affinity of the beta-receptors were assessed by the binding of [3H]DHA in an enriched ventricular membrane fraction obtained from the rat hearts 3 and 4 weeks after the application of the clip. In the rats with 3 weeks of development of hypertension no significant difference was found neither in the number nor in the affinity of receptors (30.9 +/- 5.3 fmol/mg protein, KD: 1.62 +/- 0.43 nM) compared to the control rats (33.3 +/- 6.3 fmol/mg protein, KD: 2.21 +/- 0.59 nM). In rats with 4 weeks of development of hypertension, there was an increased number of receptors (54.7 +/- 3.7 fmol/mg protein, KD: 1.41 +/- 0.17 nM) compared with control rats studied in paralleled conditions (40.0 +/- 2.3 fmol/mg protein, KD: 1.13 +/- 0.12 nM). These results suggest that the reported beta-adrenergic subsensitivity in this model of hypertensive rats could be mediated by a biochemical mechanism other than a direct alteration of the beta adrenergic receptors, and that there is a compensatory increase in the density of receptors during the development of the hypertension.
Gende
O A
OA
Camilión de Hurtado
M C
MC
Taquini
C M
CM
Gómez Llambí
H
H
Cingolani
H E
HE
D000319:Adrenergic beta-Antagonists / Q000378:metabolism*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D004082:Dihydroalprenolol / Q000378:metabolism; D006978:Hypertension, Renovascular / Q000503:physiopathology*; D008297:Male; D009206:Myocardium / Q000032:analysis / Q000378:metabolism*; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011943:Receptors, Adrenergic, beta / Q000032:analysis
D000319:Adrenergic beta-Antagonists; D011943:Receptors, Adrenergic, beta; D004082:Dihydroalprenolol; D011433:Propranolol
Receptores beta adrenérgicos miocárdicos durante el desarrollo de la hipertensión renal experimental, tipo Goldblatt II.