Differential effects of LH-RH immunoneutralization on LH and FSH secretion in the ewe.
Neutralization of LH-RH by injection of an ovine antiserum to LH-RH in ewes during the late follicular phase of the oestrous cycle resulted in an immediate blockade of pulsatile secretion of LH. Plasma concentrations of FSH gradually rose in the antiserum-treated ewes during the 36-h study period but levels declined in control ewes. These results show that, in the ewe, pulsatile LH secretion is dependent on LH-RH from the hypothalamus, while FSH is largely unresponsive to short-term reduction of LH-RH stimulation. Since reduction in LH secretion is likely to reduce ovarian function, the changes in FSH secretion may be attributed to the removal of a negative feedback influence of an ovarian factor, perhaps oestradiol, on FSH secretion.
D000818:Animals; D004971:Estrus; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood / Q000378:metabolism*; D007987:Gonadotropin-Releasing Hormone / Q000276:immunology / Q000502:physiology*; D007106:Immune Sera / Q000494:pharmacology; D007986:Luteinizing Hormone / Q000097:blood / Q000378:metabolism*; D011247:Pregnancy; D011359:Proestrus; D011388:Prolactin / Q000097:blood; D012636:Secretory Rate; D012756:Sheep; D013997:Time Factors
D007106:Immune Sera; D007987:Gonadotropin-Releasing Hormone; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone