Effects of Progestogenic Substances on the Uterine Secretion of Spayed Rats Primed with Oestradiol

Abstract

The effect of different progestogens on the properties of the uterine fluid of ligated, oestradiol-primed spayed rats were studied.The substances investigated were: pregnane derivatives: chlormadinone acetate, medroxyprogesterone acetate, dydrogesterone, and 19-nortestosterone derivatives: norethisterone acetate, norethynodrel, d1-norgestrel and lynestrenol, and their effect on uterine fluid volume and viscosity were studied.Whereas pregnane derivatives display progesterone like effects (decrease of fluid volume, increased viscosity)following both parenteral and oral administration, the effects of the 19-nostestosterone derivatives differ in some respects from those of the progesterone derivatives.Norethisterone and d1-norgestrel which still contain the 3-keto group and a double bond in 4 positions exert progesterone-like effects in low parenteral (s.c.) doses. A slight effect only being observed in response to 100 times higher oral doses.Norethynodrel and lynestrenol in which the ring A is modified exhibited no progesterone-like activity by either the subcutaneous or the oral route. Specific differences in sensitivity and in metabolic pathways can be traced as possible origin of the results obtained.

Oestrogenic sensitivity of rat uterine secretion

“…Unlike progestagens (Meglioli, Kalvoda & Desaulles, 1973), oestrogens, even in high, nonphysiological doses, did not significantly modify the viscosity and pH of the secretion, and the increase in the acidity of the uterine lumen observed after oestrogen treatment was much less pronounced than that caused by the administration of progesterone .…”

Tubal and uterine secretions; the possibilities for contraceptive attack

“…Oestrous uterine secretions In all species so far investigated, including man, ovulation is associated with the production of a voluminous, protein-rich uterine secretion of low viscosity (Lutwak- Mann, Boursnell & Bennett, 1960;Fahning, 1965;Aitken, 1970Aitken, , 1977aClemetson, Kim, DeJesus, Mallikarjuneswara & Wilds, 1973;Meglioli, Kalvoda & Desaulles, 1973). The physical function of these uterine fluids is to dilate the uterine lumen and thereby create a passage through which the spermatozoa can progress towards the utero-tubal junction.…”