[The influence of oxytocin on the membrane potentials of mammary gland secretory cells].

The effect of oxytocine and its combinations with the acetylcholine, adrenaline, atropin, and prozerin on the level of membrane potential of mammary secretory cells was studied. Short oxytocine application (5-10(-4) ME/ml) evoked hyperpolarization of the contraluminal membrane (12+/-1 mV for 54+/-5 sec). Their response was increased by joint application of acetylcholine or proserine and decreased by preliminary application of atropin. Adrenaline increased or decreased the amplitude of the membrane potential's changes and considerably reduced the duration of the oxytocine reaction. Existence of oxytocine receptors was supposed on the membrane of secretory cells, as well as the possibility of acetylcholine and adrenaline effects on the structure of oxytocine receptors or the interaction of adreno--and cholinergic receptors with the oxytocine those.