Effect of median raphe nucleus electrocoagulation and serotonin synthesis blockade on oestrogen receptor content of rat uterus.

The number of oestrogen receptors (OR) in rat uterus changes in relation to the cyclic function of the ovary. In the dioestrus phase the OR content of rat uterus is significantly greater than in the oestrus phase. Electrocoagulation of the median raphe nucleus causing in rats increased release of gonadotrophins and consequent disturbances in the cyclic ovarian function is associated also with changes in OR content of the uterus. These changes are, however, not analogous to those observed in the normal sexual cycle. In the oestrus phase a very high accumulation of OR is found in the uterus, while in the dioestrus phase OR are barely detectable. Serotonin synthesis blockade with p-CPA, which is associated with an increase in the number of maturating and mature follicles in the ovary and dioestrus phase prolongation leads to a striking increase in the number of OR in the uterus.