Perioestrous patterns of circulating LH, FSH, prolactin and oestradiol-17β in the gilt
1987; Elsevier BV; Volume: 14; Issue: 3 Linguagem: Inglês
10.1016/0378-4320(87)90084-4
ISSN1873-2232
AutoresArmelle Prunier, F. Martinat-Botté, J.P. Ravault, Sylvaine Camous,
Tópico(s)Reproductive Biology and Fertility
ResumoConcentrations of luteinizing hormone (LH), follicle stimulating hormone (FSH) and prolactin (PRL) were measured in jugular blood and those of oestradiol-17β (E217β) in utero-ovarian blood. Samples were taken from five intact gilts every 15 min for 108 h starting between day 15 and day 18 of the oestrous cycle. In the late luteal/early follicular phase, high pulsatile LH secretion, close to one pulse per hour, was observed. This could be the stimulus necessary for the final maturation of the ovarian follicles. Thereafter, frequency and amplitude of pulses, and the baseline value, decreased and were low at least between 36 and 12 h before the preovulatory LH surge. PRL and FSH concentrations also declined. This was probably due to the increase of oestrogen secretion. As E217β concentrations were still high, the surge of LH which was accompanied by increase in FSH and PRL, occurred for approximately 13 to 20 h. While LH and PRL mean levels decreased, FSH concentrations continued to increase. Peaks of PRL were observed during the late luteal/early follicular phase and during the LH discharge. During the period of estrus, each exposure to the boar was immediately followed by one of these peaks, which could play a role in the sexual behavior of the gilt.
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