A subovarian exchange mechanism for the countercurrent transfer of ovarian steroid hormones in the pig.

Sow ovaries with their ovarian pedicle were isolated and supplied with blood from the middle uterine artery. During the 30 min of infusion with [3H]testosterone into the ovarian vein 3 cm below the ovary and for the 30 min after the infusion, radioactivity was detected in tissue fluid 3 cm laterally from the ovarian vein and artery. When [3H]testosterone was infused into the muscles of the ovarian pedicle radioactivity was detected in the ovarian artery branches near the ovary. Of the total amount of blood entering the ovarian artery 63.7 +/- 4.2% reached the ovary and 36.3 +/- 3.1% travelled to the muscles and connective tissue of the ovarian pedicle. It was demonstrated that the ovarian arterial branches supplying the ovarian pedicle muscles after capillarization form the veins which descend within the ovarian artery network, redivide and create the venous mesh covering the spiralling ovarian artery branches. It is suggested that a special subovarian exchanging mechanism exists in the ovarian pedicle for countercurrent transfer of ovarian steroid hormones and that ovarian function can thereby be regulated.