Long-term effects of two antidepressants on copulatory and exploratory behaviour in the female rat.
The immediate and long-term effects of antidepressant drugs on two different behaviours--copulatory and exploratory--were compared in hormone-treated, ovariectomized rats. The drugs used were desmethylimipramine (DMI 2 and 5 mg/kg) and zimelidine (ZIM 5 and 25 mg/kg). The acute effects were studied 1-4 hours after drug injection, and the long-term effects after four weeks of daily injections. The acute treatment with DMI and ZIM significantly suppressed the lordosis behaviour compared with that in saline-treated controls. After long-term administration of DMI, the 5 mg/kg dose of this drug was still able to inhibit the lordosis response, while the low dose of DMI and ZIM did not produce a significant effect after chronic administration. We suggest that subsensitivity to certain effects of the antidepressant drugs develops during the long-term treatment.
D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology*; D002369:Castration; D003307:Copulation / Q000187:drug effects*; D003891:Desipramine / Q000494:pharmacology; D004958:Estradiol / Q000494:pharmacology; D005106:Exploratory Behavior / Q000187:drug effects*; D005260:Female; D011374:Progesterone / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D015031:Zimeldine / Q000494:pharmacology
D000928:Antidepressive Agents; D015031:Zimeldine; D011374:Progesterone; D004958:Estradiol; D003891:Desipramine