@phdthesis{oai:tsukuba.repo.nii.ac.jp:00008867,
 author = {酒井, 俊 and Sakai, Satoshi},
 month = {},
 note = {Backgroud Although it was demonstrated that circulaing endothelin (ET)-1 levels are elevated in congestive heart failure(CHF),the producion and roles of ET-1 in the failing heart are not known.We inversigated the producition of ET-1 in the heart and the densilty of myocardial ET reseptors in rats with CHF.We also inverstigated effects of intravenously infused BQ-123,an endothelin-A(ETA) receptor antagonist,on both heart rate and myocardial contractility in rats with CHF.Methods and Results We used the left coronary artery-ligated rat model of CHF(CHF rats.)Three weeks after surgery,the rats developed CHF.Plasma ET-1 concerntration was  significantly higher in the CHF rats than in the  sham-operated rats(P<.01).In the left ventricle,the expression of prepro ET-1 mRNA was markedly higher in the CHF rats than in the sham-operated rats.The peptide level of ET-1 in the ventricle was also signigicantly higher in the CHF rats than in the sham-operatede rats(500A±41vs 102A±10 Pg/g tissue,p<.01).Myocardial ET receptors were signigicantly higher in the CHF rats than in the sham-operated rats(243A±20vs 155A±17 fmolmg protein,p<05). In the CHF rats,intravenous BQ-123 infusion(0.1 mg/kg/min for120 min)significantly decreased both heart rate (p<.01)and LV+dp/dt max(p<.05),but not mean blood pressure.BQ-123 infusion did not affect these hemodynamic parameters in the sham-operated rats.Conclusions The present study demonstrated that the production of ET-1 in the heart is markedly increased,and the density of myocardial ET receptors is signigicantly elevated in the CHF rats.Intravenous BQ-123 infusion significantly reduced both heart rate and LV+dp/dt max in the CHF rats but not in the sham-operated rats.Therefore,the ET receptormediatde signal transducion system in the heart appers to be markedly stimulated in the CHF rats,and endogenous ET-1 may be involved in the mainterance of the caradiac function in these rats., 1995},
 school = {筑波大学, University of Tsukuba},
 title = {Endogenous endothelin-1 participates in the maintenance of cardiac function in rats with congestive heart failure : marked increase in endothelin-1 production in the failing heart},
 year = {1996}
}