Dissociation of beta-adrenoceptor numbers from mRNA levels during acute ischemia in rat myocardium.
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.
Nakamura
K
K
First Department of Internal Medicine, Hyogo College of Medicine, Mukogawa-cho, Nishinomiya, Japan.
Ohyanagi
M
M
Iwasaki
T
T
D000199:Actins / Q000235:genetics*; D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D017403:In Situ Hybridization; D008297:Male; D017202:Myocardial Ischemia / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis*; D051381:Rats; D017208:Rats, Wistar; D011943:Receptors, Adrenergic, beta / Q000235:genetics*
D000199:Actins; D012333:RNA, Messenger; D011943:Receptors, Adrenergic, beta; D000262:Adenylyl Cyclases