
TY  - JOUR
A1  - Gootwine, E 
A1  - Bor, A 
A1  - Shalhevet, D 
A1  - Zenou, A 
A1  - Braw-Tal, R 
T1  - Differential pituitary response to GnRH in pregnant Booroola-Assaf and Assaf ewes
JF  - Reproduction, Fertility and Development
JO  - Reprod. Fertil. Dev.
Y1  - 1992
VL  - 4
IS  - 2
SP  - 231
EP  - 237
KW  - 
UR  - https://doi.org/10.1071/RD9920231 
N2  - Pituitary response to exogenous gonadotrophin-releasing hormone (GnRH) was examined at a late stage of pregnancy in 10 Booroola-Assaf ewes heterozygous at the FecB locus (FecBFec+) and in 11 Assaf ewes that were non-carriers (Fec+Fec+). Basal plasma luteinizing hormone (LH) and follicle stimulating hormone (FSH) concentrations were similar in the two genotypes. Administration of 100 micrograms of GnRH resulted in a significant increase (P < 0.05) in plasma LH and FSH concentrations in most of the ewes treated. Maximal responses were observed 105-135 min after GnRH treatment. Pituitary responses to GnRH were significantly lower (P < 0.05) in Booroola-Assaf than in Assaf ewes. The decreased pituitary responsiveness observed in FecB gene carriers compared with Fec+Fec+ ewes might be due to differences in the concentrations of ovarian or uterine hormones modulating the release of gonadotrophin. The results suggest that FecB-specific differences can be observed at the pituitary level. 
ER  -

