Table 1. Serum hormone level in non ovariectomized rat at different phases of the estrous cycle.

Hormones	Estrous cycle	Hormone level
		(Mean ± SEM)
Oestrogen	Proestrus	39.38 ± 4.56 pg/ml
	Estrus	12.64 ± 2.98 pg/ml
	Metestrus	8.03 ± 1.09 pg/ml
	Diestrus	16.49 ± 2.32 pg/ml
Progesterone	Proestrus	22.87 ± 2.65 ng/ml
	Estrus	14.92 ± 2.05 ng/ml
	Metestrus	16.96 ± 2.73 ng/ml
	Diestrus	24.03 ± 3.08 ng/ml
Relaxin	Proestrus	12.34 ± 3.96 pg/ml
	Estrus	8.04 ± 1.17 pg/ml
	Metestrus	9.48 ± 1.75 pg/ml
	Diestrus	18.03 ± 2.85 pg/ml