Idazoxan decreases estrogen-induced lordosis in female but not "hormone-independent" lordosis in male guinea pigs of an inbred strain.
This experiment examined whether the imidazoline idazoxan (which binds to alpha-noradrenergic receptors and to imidazoline-preferring sites) interferes with hormone-dependent or hormone-independent lordosis responses. Ovariectomized (ovx) Strain 2 female guinea pigs which were sexually receptive after receiving estradiol benzoate (EB; 3 micrograms/d for 3 days) were injected with either idazoxan (10 mg/kg) or with vehicle at 24 hr after the last EB injection. Idazoxan significantly decreased EB-facilitated lordosis responses in these females. Castrated Strain 2 males, which show lordosis behavior without gonadal hormone administration, were injected with the same dosage of idazoxan (10 mg/kg) or with vehicle. Idazoxan did not inhibit lordosis behavior in these males.
Thornton
J E
JE
Institute of Animal Behavior, Rutgers University, Newark, New Jersey.
Roy
M
M
Vincent
P
P
Goy
R W
RW
McEwen
B S
BS
Feder
H H
HH
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000818:Animals; D004146:Dioxanes / Q000494:pharmacology*; D004347:Drug Interactions; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D006168:Guinea Pigs; D019329:Idazoxan; D007267:Injections; D008141:Lordosis / Q000139:chemically induced*; D008297:Male; D010052:Ovariectomy; D011374:Progesterone / Q000494:pharmacology; D012727:Sex Characteristics; D013997:Time Factors
D000317:Adrenergic alpha-Antagonists; D004146:Dioxanes; D004967:Estrogens; D011374:Progesterone; D019329:Idazoxan