Luteotrophic effect of deciduoma in rats.

Abstract

Luteotrophic effect of decidual tissue was examined in Holtzman rats by observing length ofpseudopregnancy or by measuring progesterone and 20α-hydroxyprengn-4-en-3-one (20a-OHP) in>ovarian effluent blood plasma.
The length of pseudopregnancy was significantly longer in traumatized rats than in hysterecto->mized-pseudopregnant animals (23.0±0.97 υs 19.3±0.93; mean±SE). When deciduomectomy (removalof uterus bearing deciduomata) was performed on days 7 and 9, pseudopregnancy lasted only 17.4±0.92 and 19.4±1.25 days, respectively, which were similar to the value observed for hysterecto-mized-pseudopregnant animals.
Progestin levels in both the traumatized and the hysterectomized-pseudopregnant rats were>similar to each other on day 7. An increase in progestin levels, however, occured in traumatizedanimals from days 7 to 9 of pseudopregnancy and the levels of progesterone and 20α-OHP on day >9 were significantly higher in the animals with deciduomata by 1.6- and 2.2-fold, respectively, ascompared with those in hysterectomized-pseudopregnant ones. Following deciduomectomy on day 7, the increase in each progestin level from days 7 to 9 was not seen. On the other hand, hypophy->sectomy performed on day 7 in traumatized rats resulted in a dramatic decrease in progesteronelevel coincident with an increase in 20α-OHP level on day 9 without changing total progestin level(sum of progesterone and 20α-OHP).
Thus, the luteotrophic action of decidual tissue was suggested by the prolongation of pseudo-pregnancy and the elevation of ovarian progesterone secretion, and it was not seen in the absence of pituitary.