RAPID ABSORPTION AND LOCAL REDISTRIBUTION OF PROGESTERONE AFTER VAGINAL APPLICATION IN GILTS

Catheters were implanted in 6 anaesthetized gilts (3 animals in the fo llicular phase, 3 in the luteal phase) into a carotid artery and into the utero-ovarian vein and uterine artery on both sides. The uterine l umina were closed by a suture. Further, a catheter was inserted into t he vagina after which the animals were allowed to recover. Tritiated p rogesterone was infused into vagina the following day during a 2 min p eriod and simultaneous blood samples collected from the 5 catheters ev ery 10 min for 2 h after which the animals were sacrificed. Tissue sam ples were obtained from the genital organs. The results showed a rapid absorption of progesterone from the vaginal lumen and a marked redist ribution to the genital organs. The increased level of radioactivity i n the plasma samples collected from the uterine arteries compared to t he simultaneous samples from the carotid artery in 2 of the 3 animals in the luteal phase indicates the existence of a local redistribution system.