[Expression of beta2-adrenergic receptor and its effect on the proliferation of neonatal rat cardiac fibroblasts].
The expression of beta-adrenergic receptor subtypes and its effect on neonatal rat cardiac fibroblast proliferation were investigated by radioligand binding assay and [(3)H]-thymidine incorporation analysis, respectively. The results indicated that there was no significant difference in the beta-adrenergic receptor density (B(max)) and affinity (K(D)) between cardiomyocytes and cardiac fibroblasts. The [(125)I]-pindolol competitive inhibition curves (ICI 118551 and CGP 20712A) were significantly better fit in a one-site model in membrane preparation of cardiac fibroblasts. In cultured cardiac fibroblasts, 0.1 micromol/L isoproterenol-induced [(3)H]-thymidine incorporation was completely inhibited by a selective beta (2)-AR antagonist ICI 118551, or a non-selective beta-AR antagonist propranolol, but not by CGP 20712A, a selective beta(1)-AR antagonist. These results suggest that isoproterenol-induced cardiac fibroblast proliferation is mediated by beta(2)-AR, the preponderant beta-AR subtype in cardiac fibroblasts.
Yin
Feng
F
Institute of Vascular Medicine, Peking University Third Hospital, The Reference Laboratory of Ministry of Education for Molecular Cardiovasology, Beijing 100083.
Lu
Zhi-Zhen
ZZ
Han
Qi-De
QD
Zhang
You-Yi
YY
D000818:Animals; D000831:Animals, Newborn; D049109:Cell Proliferation; D002478:Cells, Cultured; D005347:Fibroblasts / Q000166:cytology* / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D018343:Receptors, Adrenergic, beta-2 / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*
D018343:Receptors, Adrenergic, beta-2