Ca2+/calmodulin system: participation in the progesterone-induced facilitation of lordosis behavior in the ovariectomized estrogen-primed rat.
We studied the effect some drugs that participate in the Ca2+/ calmodulin system have on the progesterone (P) facilitation of lordosis behavior in ovariectomized estradiol (E2) primed rats. We injected rats 44 h after E2 priming with 2 mg P together with various dosages of one of the following compounds: pentobarbital, trifluoperazine (TPZ), promethazine (PMZ), Chlorpromazine (CPZ), haloperidol (HAL), pimozide (PIM), and verapamil (VER). Then 4 h after treatment, animals were tested for sexual behavior, expressed as the lordosis quotient (LQ). All drugs at 4 mg/kg or higher inhibited lordosis, but only HAL, PIM, and VER were active at 1 mg/kg. The maximum level of activity was shown by PIM, although at the dose of 8 mg/kg no statistical differences were found between this compound and TPZ or HAL. Pentobarbital (25 mg/kg) showed no significant difference from saline-treated controls. The activity of the tested drugs on the facilitation of sexual behavior appears to be related to their efficiency as inhibitors of calmodulin (CaM)-dependent phosphodiesterase and as ligands for the Ca(2+)-CaM complex.
Canchola
E
E
División de Ciencias Biológicas y de la Salud, Universidad Autónoma Metropolitana, Unidad Iztapalapa, Mexico City, Mexico.
Rodríguez-Medina
M
M
Dueñas-Tentori
H
H
Mercado
E
E
Rosado
A
A
D000818:Animals; D002118:Calcium / Q000502:physiology*; D002147:Calmodulin / Q000037:antagonists & inhibitors / Q000502:physiology*; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D010052:Ovariectomy; D011187:Posture / Q000502:physiology; D011374:Progesterone / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012726:Sexual Behavior, Animal / Q000187:drug effects*
D002147:Calmodulin; D011374:Progesterone; D004958:Estradiol; D002118:Calcium