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Biomedical subjects

Y Hara

Publications and source records attributed to Y Hara.

At least 793 records · Page 44Linked to original sources
PubMed1979

[Pharmacological properties of dl-2-(3'-t-butylamino-2'-hydroxypropylthio)-4-(5'-carbamoyl-2'-thienyl) thiazole hydrochloride (S-596), a new beta-adrenergic blocking agent (author's transl)].

We developed a new beta-adrenergic blocking, antiarrhythmic compound S-596 and compared the findings with those of propranolol or practolol. S-596 antagonized the positive chronotropic and inotropic actions of adrenaline in isolated guinea-pig atria, and blocked the relaxant response to adrenaline of isolated guinea pig tracheal strips. In anesthetized mongrel dogs, S-596 given intravenously inhibited increases in heart rate and myocardial contractile force and decreases in systemic blood pressure induced by isoproterenol. In conscious dogs, the oral administration of S-596 reduced the isoproterenol induced tachycardia and the maximal effect was attained one hour after administration. In this regard S-596 was about 5 times more potent than propranolol, and S-596 was significantly longer-acting than propranolol. Thus, S-596 has greater beta-blocking activity than propranolol. S-596 has a lesser degree of myocardial depressant action than propranolol in spontaneously contracting rat or guinea pig atria and no intrinsic sympathomimetic activity in reserpinized rats. S-596 also has a weaker local anesthetic and antiarrhythmic activity than propranolol, as determined in guinea pigs and rabbits.

Adrenergic beta-Antagonists↗
PubMed1978

Synthesis and beta-adrenergic blocking action of a new thiazolylthiopropanolamine derivative.

The synthesis of (+/-)-2-(3'-tert-butylamino-2'-hydroxypropylthio)-4-(5'-carbamoyl-2'-thienyl)thiazole hydrochloride is described. The new compound antagonized the cardiovascular effects, such as positive chronotropic, positive inotropic, or depressor arterial blood pressure responses, elicited by intravenous isoproterenol; it was 9--14 times as potent as propranolol in anesthetized open chest dogs. The oral administration of the compound reduced isoproterenol tachycardia in conscious dogs. It was about five times as potent as propranolol in this test, with maximal action after 1 hr, and its duration was significantly longer than that of propranolol.

Adrenergic beta-Antagonists↗