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
Copyright© The Japanese Pharmacological Society 1997
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