RESUMO
OBJECTIVE: Mast cell population and histamine affect on blastocyst implantation. This study aimed to evaluate the effects of progesterone administration after induction of ovulation on the uterine tissue mast cell population and histamine content in mice. METHODS: We ran an experimental study on three groups of mice; control group, ovulation induction (induction group), and ovulation induction along with progesterone administration (progesterone group). Mast cells were counted using toluidine blue staining, and the histamine level was measured through spectrophotometry. RESULTS: According to the analysis of variance (ANOVA), there was no difference in mast cell population in endometrium (p=0.138) nor in myometrium (p=0.611). The ratio of mast cells in the myometrium per endometrium increased in the progesterone group in comparison to the control group based on a generalized linear model (p=0.041). The uterine histamine level was different between the groups, based on the ANOVA (p=0.039), in which the progesterone group had lower amounts of histamine. CONCLUSIONS: Progesterone administration after ovulation induction did not decrease the number of endometrial mast cells and could have increased the ratio of myometrium mast cells per endometrium mast cell. The histamine level in uterus decreased by the administration of progesterone in the ovulation-induced mice.
