[Effect of a flavinoid (4-methylesculetin) on the response of isolated calf coronary arteries to histamine in the presence of indomethacin]. / Influenza di un flavonoide (4-metilesculetolo) sulla risposta di arterie coronarie di vitello isolate all'istamina in presenza di indometacina.

The aim of this work is to study the mechanism by which 4-methylesculetin (4-Me) cause the relaxation or inhibit the histamine induced contraction in the smooth muscle. The effect of 4-Me, alone or associated with ascorbic-acid, on basal tone and histamine induced contraction of isolated coronary strips have been studied. Experiments have been carried out in the presence of indomethacin (IN), specific inhibitor of prostaglandin synthetase. IN-decreased, but did not abolished, the 4-Me induced relaxation and reduced or suppressed the depressive effect of 4-Me on the histamine dependent contraction. Therefore, it seems reasonable to conclude that the 4-Me influence could be mediated by prostaglandins release in the smooth muscle.

[Inhibitory effect of methergoline on serotonin induced contraction of isolated strips of coronary arteries]. / Effetto inibitorio della metergolina sulla contrazione indotta da serotonina, di segmenti di arterie coronarie isolate.

Metergoline (antiserotonin drug) prevents the contraction induced by serotonin on strips of isolated coronary arteries. Moreover when metergoline is added at the maximal contraction, it induces relaxation of the vascular smooth muscle preceeded by a brevious phase of contraction.