Effect of histamine on the myoelectrical activity of uterus in sheep sensitized and non-sensitized by stilboestrol

Experiments were carried out on seven anestrus ewes. The animals were implanted with bipolar electrodes in the horns and corpus uteri. The electrical activity was registered by Reega Duplex electroencephalograph. The experiments were carried out on non-sensitized ewes and ewes sensitized by stilboestrol. The sheep were first fitted with an external jugular vein catheter and histamine (Histaminům hydrochloricum - Polfa) - 3 μg . kg-1 • min-1 - or H1 -receptors blocker (Clemastinum-Polfa) - 50 μg • kg-1 - were introduced. It was found that in sheep sensitized by stilboestrol histamine caused an increase in myoelectrical activity of the uterus by stimulation of H1 - histaminergic receptors.