[The contractile activity of the isolated mesenteric artery at different pH values of the perfusion solution].

Tonus of the proximal, medial and distal portions of the rat mesentery artery did not respond to the pH shifts in the perfusion fluid. However, the pH shift to 6.6 reduced the vessel sensitivity to noradrenaline (NA) as well as its constrictor response to electrical stimulation (ES). The pH shift to 7.8 augmented the medial and distal segments' dilatation in response to the ES at the NA concentration 10-5. The proximal portion had different responses. The data obtained suggest that acidosis exerts a depressive effect upon the mesentery artery's responsiveness to the NA and ES, and that the alkalosis exerts a potentiating effect upon the ES-induced vasodilatation.