INVOLVEMENT OF ADRENOCEPTORS IN THE OVARIAN VASCULAR PEDICLE IN THE REGULATION OF COUNTER CURRENT TRANSFER OF STEROID-HORMONES TO THE ARTERIAL BLOOD SUPPLYING THE OVIDUCT AND UTERUS OF PIGS

1 On Day 10 of the oestrous cycle in pigs, after laparotomy noradrenal ine (NA), methoxamine (alpha(1)-adrenomimetic, M), Prazosin (alpha(1)- adrenolytic, Pr) in total doses of 4 mu mol, and saline were infused ( 10 min) into the superficial layer of mesovarium on both sides of the ovarian pedicle vasculature, close to the ovary. 2 Bloodflow in the ov arian artery, heart rate and progesterone (P-4) and androstenedione (A (4)) secretion from the ovary and their concentrations in the ovarian venous effluent, as well as the concentrations of P-4 and A(4) in the blood supplying the oviduct and the uterus, were determined. 3 A signi ficant increase of P-4 and A(4) secretion after NA and M infusion and increased concentrations of P-4 and A(4) in the ovarian venous effluen t were found, but these changes did not influence the counter current transfer of hormones from the venous effluent into arterial blood supp lying the oviduct and the uterus. 4 Infusion of Pr caused a significan t decrease of P-4 and A(4) secretion and their concentrations in the o varian venous effluent and significantly increased A(4) concentration in the blood supplying the oviduct and uterus. 5 The results indicate that stimulation of alpha(1)-adrenoceptors in the area of ovarian vasc ulature did not influence, whereas block of alpha(1)-adrenoceptors aff ected, the local concentration of steroid hormones in the blood supply ing the oviduct and the part of the uterus proximal to the ovary, desp ite the changes in the concentrations of steroid hormones in the ovari an effluent.