Biochemical aspects of rat deciduomata as affected by an oxazolidinethione

Abstract

Traumatization of uteri of pseudopregnant rats provides an experimental means of approximating the decidual changes which occur in the uterus during the period of implantation. In such a preparation, progesterone (1. 5 mg/day) injected from day 5 through 9 of pseudopregnancy increased the weight and the RNA [ribo-nucleic acid] protein, and glycogen concentrations and decreased the DNA [deoxyribonucleic acid] concentration and percent dry weight. Estradiol (0. 05 [mu]g/day) alone caused only a reduction in DNA concentration of the parameters assessed, but greatly enhanced the progestational effects when the 2 steroids were administered concomitantly. 5-([alpha], [alpha],[alpha]-Trifluoro-m-tolylocymethyl)-2-oxazolidinethione, an effective inhibitor of pregnancy, reversed these steroid-dependent changes as well as the uptake of P32 in the decidualizing tissue. However, tritium incorporation into rat deciduomata after injection of either estradiol-17[beta]-6, 7-H3 or progesterone-7[alpha]-H3 was not significantly affected. The apparent lack of hormonal properties and of systemic toxicity associated with fully effective doses of this compound is unique among inhibitors of deciduomata formation.