Table 2.

Effects of acute cortisol on GnRH and LH pulses in natural follicular phase

Treatment	Pulse frequency (pulses/6 h)		Pulse amplitudea
	14–20 h	20–26 h	14–20 h	20–26 h
GnRH
Vehicle, vehicle	7.0 ± 0.3	6.7 ± 0.8	1.8 ± 0.4	1.2 ± 0.3b
Vehicle, cortisol	6.3 ± 0.7	6.3 ± 1.2	1.9 ± 0.6	0.9 ± 0.2b
LH
Vehicle, vehicle	6.6 ± 0.4	6.1 ± 0.6	1.2 ± 0.2	0.9 ± 0.1c
Vehicle, cortisol	6.1 ± 0.5	5.4 ± 0.5	1.5 ± 0.3	0.8 ± 0.1c,d

Values are mean ± sem for seven control (vehicle, vehicle) and seven experimental (vehicle, cortisol) ewes. 

^aAmplitude expressed as pg/min for GnRH and ng/ml for LH. 

^bPeriod effect (14–20 vs. 20–26 h; P < 0.01) as determined by repeated measures ANOVA. 

^cPeriod effect (14–20 vs. 20–26 h; P < 0.0001) as determined by repeated measures ANOVA. 

^dTreatment × period interaction (P < 0.05) as determined by repeated measures ANOVA.