Regulation of gonadotrophin function in hemidecorticate rats.
The present review focuses on some aspects of the regulation of gonadotrophin (LH and FSH) and prolactin secretion in rats submitted to hemidecortication (HD). The removal of rhinencephalic and cortical structures induces the following changes: Irregular and erratic estrous cycle; Increase in LH and FSH secretion in the afternoon of proestrus and after uni- or bilateral castration; When hormonal replacement therapy was administered to castrated female rats, the controls needed larger doses of estradiol benzoate (E2) to reduce LH levels than the HD animals, which suggests an increase in the sensitivity of the hypothalamus-hypophysis axis to gonadal steroid negative feedback. When HD was performed during the neonatal period (1-3 days old), an earlier onset of puberty and sexual maturation was observed in both female and male HD rats than in controls. During the puberal evolution the HD male rats showed elevation in plasma testosterone levels, an increase in the testicular response to hCG and also in the number of testicular binding sites to LH and FSH at 38-43 days (before the onset of puberty) and to prolactin (after 60 days). The results suggest that after removal of cortical and subcortical structures (HD), with predominant inhibitory influences, the hypothalamus-hypophysis becomes more sensitive to the LH and FSH releasing mechanisms.
D000367:Age Factors; D000818:Animals; D002540:Cerebral Cortex / Q000502:physiology*; D004971:Estrus; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood / Q000378:metabolism*; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology; D007986:Luteinizing Hormone / Q000097:blood / Q000378:metabolism*; D008297:Male; D010052:Ovariectomy; D011388:Prolactin / Q000097:blood / Q000378:metabolism*; D051381:Rats; D012741:Sexual Maturation; D013739:Testosterone / Q000097:blood
D013739:Testosterone; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone