Effect of intrauterine injection of chlorpromazin on implantation in the rat

In rats, injection of chlorpromazin hydrochloride (CPZ), a calmodulin antag onist, to each uterine horn had a significant (87%) anti-implantation effec t and 100% antifertility effect. Both of these rates were zero in the salin e control group. Polyacrylamide gel electrophoresis analysis of the uterine fluid showed a decrease in the protein content and certain changes in its chemical composition, in particular, a marked reduction in the number of ba nds of estradiol-induced 70 kD proteins in the experimental group. No signi ficant difference was found in the ovarian weight and the serum estradiol ( E-2) and progesterone (P) levels between the two groups. These results sugg est that calmodulin influences the process of implantation and this effect is not directly related to the serum concentrations of E-2 and P. It is bel ieved that CPZ probably exerted its antiimplantation effect by a direct act ion on the uterus. (C) 1998 Elsevier Science Inc. AII rights reserved.