Preovulatory secretion of gonadotrophins and TSH in cyclic rats with small lesions in the preoptic area.
Animals with unilateral or bilateral lesions, with respectively 85 and 70% of intact preoptic area tissue remaining, returned to regular oestrous cycles. By comparison with sham-operated controls, rats with lesions had more days with a leucocytic smear in each of the 1st, 2nd or 3rd post-operative cycle, before returning to a 4-day cycle. Hormone measurements of blood collected during the afternoon of pro-oestrus showed that, in rats with bilateral lesions, the duration of the preovulatory LH secretion was significantly shortened, although peak levels were unchanged; the initial phase of the preovulatory FSH secretion was lost; and much of the prolactin surge was also inhibited. The TSH surge was unaffected.
D000818:Animals; D005260:Female; D006065:Gonadotropins, Pituitary / Q000097:blood / Q000378:metabolism*; D007031:Hypothalamus / Q000502:physiology*; D010060:Ovulation; D011301:Preoptic Area / Q000502:physiology*; D051381:Rats; D013972:Thyrotropin / Q000097:blood / Q000378:metabolism*; D013997:Time Factors
D006065:Gonadotropins, Pituitary; D013972:Thyrotropin