
TY  - JOUR
A1  - Thomas, GB 
A1  - Martin, GB 
A1  - Ford, JR 
A1  - Moore, PM 
A1  - Campbell, BK 
A1  - Lindsay, DR 
T1  - Secretion of LH, FSH and Oestradiol-17ß During the Follicular Phase of the Oestrous Cycle in the Ewe
JF  - Australian Journal of Biological Sciences
JO  - Aust. Jnl. Of Bio. Sci.
Y1  - 1988
VL  - 41
IS  - 3
SP  - 303
EP  - 308
KW  - 
UR  - https://doi.org/10.1071/BI9880303 
N2  - Plasma concentrations of LH, FSH and oestradiol-17iJ were measured in blood samples taken at 15 min intervals for 48 h during the follicular phase of four Merino ewes. The amplitude of pulses of LH and the mean concentration of LH were higher at the beginning of the follicular phase, 36-24 h before the preovulatory surge of LH (amplitude 2·4 ng ml- 1, mean concentration 3·9 ng ml- 1), than at the end, 24-0 h before the preovulatory surge (amplitude 1· 2 ± 0·1 ng ml- 1; mean concentration 1·4 ± 0·1 ng ml- 1). There was no change in the inter-pulse interval during this time (mean 74 ± 5 min). Over the same period, oestradiol levels increased from 7-8 pg ml- 1 to a peak of 10- 15 pg ml- 1. Mean FSH concentrations declined (36-24 h: 3· 6 ng ml - 1 vs 24-0 h: 1· 8 ± O· 3 ng ml- 1) before rising at the time of the preovulatory surge of LH and again 24 h later. It was concluded that the biphasic response of LH to oestrogen that is seen in ovariectomized ewes may also operate during the follicular phase of the oestrous cycle in entire ewes. 
ER  -

