Jpn. J. Pharmacol. 73 (1), 23-28 (1997)

Dissociation of beta-Adrenoceptor Numbers from mRNA Levels during Acute Ischemia in Rat Myocardium

Kiyoko Nakamura, Mitsumasa Ohyanagi (*) and Tadaaki Iwasaki

First Department of Internal Medicine, Hyogo College of Medicine, 1-1, Mukogawa-cho, Nishinomiya 663, Japan
(*) To whom correspondence should be addressed.

Abstract: To explore alterations in messenger RNA (mRNA) for the beta-adrenoceptor (beta-AR) in ischemic myocardium, we compared the mRNA levels for beta-AR in ischemic and nonischemic myocardium by in situ hybridization using a radioisotope imaging system. We also compared these mRNA levels in ischemic and nonischemic myocardium with the number of the beta-AR by radioligand binding assay. The mRNAs for beta-AR were diffusely distributed in normal hearts. The level of mRNA detected by in situ hybridization was reduced by acute ischemia, whereas the number of beta-AR was increased. Although the number of beta-AR was increased in the myocardium with one or three hours ischemia, the total function in beta-AR-stimulatory G protein-adenylate cyclase system was not changed. There is a discrepancy between beta-AR mRNA and protein levels in the acute ischemic rat ventricular myocardium.

Keywords: beta-Adrenoceptor, Ischemia, mRNA, In situ hybridization

Copyrightę The Japanese Pharmacological Society 1997

[Back to TOC]