@article{oai:niigata-u.repo.nii.ac.jp:00018069,
 author = {渡辺, 賢一},
 issue = {6},
 journal = {新潟医学会雑誌, 新潟医学会雑誌},
 month = {Jun},
 note = {"The norepinephrine (NE) concentration in the rat myocardium was determined. In fetus of Wistar-kyoto rat (WKY) and spontaneously hypertensive rat (SHR), cardiac epinephrine (E) concentration was high. With the growth of rats, cardiac E concentration went down, while a rapid increase of cardiac NE concentration appeared. Cardiac NE concentration of SHR became higher than that of WKY significantly in 16 week-old rats. The effects of chronic treatment with bunazosin, atenolol and verapamil on the myocardium of SHR were examined by the radioligand binding assay method using [＾3H]prazosin, [＾<123>I] iodocyanopindolol and [＾3H] nitrendipine binding to α_1- and β_1-adrenergic receptors and Ca^<2+> antagonist receptors. (1) All of these drugs lowered the elevated blood pressure of the SHR. (2) Administration of atenolol to the SHR decreased the Bmax value of the β_1-adrenoceptor. (3) Verapamil, bunazosin and atenolol also lowered the Bmax values of the Ca^<2+> antagonist receptor of SHRs. (4) All drugs except for atenolol lowered NE concentration in the myocardium of the SHR.These findings suggest that the SHR has an abnormality of the α_１-and β_1-adrenoceptors and Ca^<2+> antagonist receptor of the myocardium, that the drugs had a beneficial effect on these receptors, that the drugs could also lower the high NE content in the myocardium of the SHR and that some of these drugs also affected the binding characteristics of other types of membrane receptors. \n", Changes were examined in myocardial catecholamine content and α_1-and β_1-adrenoceptors and Ca^<2+> antagonist receptor during the development of cardiomyopathy in Syrian hamsters (Bio 14.6) and age-matched healthy controls. In addition, the effects of bunazosin, atenolol, xamoterol (β_1-partial agonist) and verapamil on the catecholamine content and [＾3H] prazosin, [＾3H] CGP 12177 and [＾3H] nitrendipine bindings to α_１-and β_1-adrenergic receprors and  Ca^<2+> antagonist receptor of myocardium were compared with those of the controls. (1)Lower NE and dopamine levels were observed in 35-week-old cardiomyopathic hamster hearts than in the controls. There was, however, a  tendency for a slight decrease of α_１-and β_1-adrenoceptors and a slight increase of Ca^<2+> antagonist receptors in cardiomyopathic hamsters. (2) Administration of bunazosin induced lower dopamine values in 18-week-old cardiomyopathic hamsters. (3)Xamoterol induced a higher Kd value for β_1-adrenoceptors and lower dopamine content htan for those with cardiomyopathy. Thus, drug treatments clealy chang catecholamine content and binding characteristics of the adrenoceptors which play an important role in the development of cardiac hypertrophy and heart failure. Xamoteol was given orally for 7 days (100mg twice daily) to healthy volunteers and patients with heart failure (CHF). Lymphocyte β_adrenoceptor density (Bmax) and affinity were determined by radioligand binding assay using ^<125>Ｉ-ＩCYP before and after the treatment. Bmax was lower in the patient group compared with control group. Following withdrawal of the treatment, Bmax decreased in both grouos. Blood pressure rose slightly in both groups. The long-term effects after 3 and 12 months of treatment with xamoterol were assessed. Xamoterol incresed exercised tolerance after 12 months treatment. Echocardiographic fractional shortening increased and pulmonary wedge paessure (PAW) during exercise at the same work load decreased at 3 months. Resting PAW and exercise heart rate decreased at 3 months. The density of the β-adrenoceptors in lymphocytes increased at 3 and 12 months. The relation between the progression of the hypertension and cardiac catecholamine concenreations was strongly suggested. β-adrenoceptor in myocardium was lower in CHF compared with contorl. Xamoterol demonstraed both β-agonist and antagonist effects in CHF and cardiomyopathic patients. β-adrenoceptors in lymphocytes were up-regrated during treatment with xamoteol without deterioration in cardiac function in the patient with CHF.},
 pages = {202--206},
 title = {2) 心不全モデル動物および心不全患者の成因と薬物治療について(シンポジウム 血管細胞生物学の進歩, 第517回新潟医学会)},
 volume = {110},
 year = {1996}
}