INFLUENCE OF HYPERPROLACTINEMIA INDllCED EXPERIMENTALLY ON THE HYPOTHALAMO-lIYPOPHYSIAL GONADAL AXIS IN ADULT FEMALE ALBINO RATS

Prolactin secretion by the pituitary gland is under predominantly negative control by the hypothalamus (Leong et at, 1983). A physiological rise in plasma prolactin level occurs during pregnancy and early in lactation. The introduction of the
assay of prolactin in human serum during 1970, resul,tC"d in the definition of hyperprolactincmia syndrome i.e, menstrual disturbance, infertility and galactorrhea in women. The principal modes of presentation of hypcrprolactincrnia in women arc infertility and menstrual disorders (Guunasthe, 1993).
Most of the previous works have been carried out to investigate the pathophysiological aspect of nyperprolacunemia associated infertility. However, litrle attention has been paid to the histopathological changes that occur in the female reproductive system in such circumstances. From the available literature, no histological studies dealing with the effect of
experimentally-induced hypcrprolactinerniu on the neurons of the hypothalamic nuclei or the pituitary gland were previously done. Varied literature supported the view that the arcuate nucleus provides the final common neurosecretory pathway over which the C.N.S controls the anterior pituitary gland (Everitt et ul., 1986). Effects of gonadal steroids on the hypothalamus are ultimately translated into alterations in , the pituitary secretory activity with subsequent change in the endocrine gland which are dependent on pituitary hormones (Farnworth, 1995). Sulpiride is a potent antidopaminergic agent with antipsychotic and antidepressant activity (Serra et at, 1990). It acts on prolactin and gonadotrophic secretion. Therefore, this work was carried out to study the changes that would occur in response to experimentally induced hyperprolactincmia using sulpiride in the hypothalamo- hypophysial gonadal axis. The results will he used to evaluate the deleterious effects of hypcrprolactinemia towards further understanding the exact pathological changes involved in associated reproductive disorders.The structure of arcuate nucleus of hypothalamus, gonadotrophs and mamrnotrophs of the pars distalis and the ovary in sulpiridc induced hypcrprolactinernic albino rats will be investigated in this work using histological, immunocytochemical as well as ultrastructural techniques.