Table 2.

Estrogen levels of female rats influence cocaine administration.

Estrogen Level	Strain/Age	Cocaine Dose	Cocaine Self-Administration	References
Intact during estrus phase (high levels of estradiol)	Sprague-Dawley rats	0.5 mg/kg per infusion	Increases	[47]
		0.5 mg/kg per infusion	Increases	[48]
Intact during non-estrus phases (low levels of estradiol)	Sprague-Dawley rats	0.5 mg/kg per infusion	Decreases	[47]
		0.5 mg/kg per infusion	Decreases	[48]
Ovariectomized	Sprague-Dawley rats about 3 months of age	1.5 mg/kg per infusion	Decreases	[49]
		0.4 mg/kg per infusion	Decreases	[50]
Ovariectomized with estradiol treatment	Sprague-Dawley rats about 3 months of age	1.5 mg/kg per infusion	Increases	[49]
		0.4 mg/kg per infusion	Increases	[50]