Luteinizing Hormone and Progesterone in Peripheral Blood During the Ovulatory Cycle of the Hen Gallus Domesticus

Abstract

Radioimmunoassays were used to estimate luteinizing hormone (LH) and progesterone in samples of blood taken from individual hens at frequent intervals throughout their respective ovulatory cycles. A consistent pattern in the plasma levels of both hormones was observed. Significantly more LH and progesterone was present in plasma 4\p=n-\7h before ovulation than at other times during the cycle. An increase in the level of progesterone either preceded that of LH or the two hormones increased simultaneously. At no time did an increase in the level of LH occur before the rise in progesterone.In those birds which did not ovulate during the experimental period the levels of both hormones remained low. The significance of these findings in relation to the neuroendocrine control of ovulation in the hen is discussed.

Comparisons of time intervals and plasma LH concentrations during the ovulatory cycle of broiler breeder hens maintained under either a 24 H light:dark cycle or continuous light

“…1984). Our results confirm the findings of earlier studies of laying strain hens in 24-h lightrdark cycles (Furr et al, 1973;Shodono et al, 1975;Etches and Cunningham, 1977;Gow et al, 1985) or in continuous light (Gow et al, 1986). In comparison with Australorp and White Leghorn hens maintained under both lighting conditions (Gow et al, 1985;, the broiler breeder hens had plasma LH concentrations during mid-sequence ovulatory cycles which were intermediate between those in the two laying breeds.…”

Effect of photoperiod on gonadotrophin concentrations in domestic turkeys

“…The interval between the LH peak and oviposition was between 30 and 36 h. However, as the egg remains in the oviduct for 25 to 29 h (Wolford et al, 1964) the LH peak probably occurs about 6 h before ovulation. The LH profile during the ovulatory cycle in the turkey is comparable with that in the domestic fowl (Furr et al, 1973). The absence of significant changes in the FSH concentrations during the ovulatory cycle of the turkey may be due to the large variations between birds, and the small number of hens used.…”

Effect of ovine LH on the progesterone content of the granulosa cells in preovulatory follicles of the domestic fowl (Gallus domesticus)

“…A simple Chromatographie step on a Florisil column (Culbert & Wells, 1973) produced a fraction which was sufficiently purified for g.l.c. (Furr et al, 1973;Williams & Sharp, 1978a (Huang et al, 1979;Wells et al, 1980). Cells collected from follicles estimated to be ovulating 1-5, 24 and 48 h later responded simUarly to exogenous ovine LH with increased secretion of progesterone.…”