Possible participation of D3 and D4 dopaminergic receptors on genital reflexes induced by cocaine in paradoxical sleep deprived male rats.
Previous studies have demonstrated that paradoxical sleep deprivation (PSD) potentiates cocaine-induced genital reflexes in male rats and both D1 and D2 receptors may play a role in those effects, and to examine the possibility that such might involve other dopaminergic receptors, we investigated the effects of D3 and D4 receptor subtype antagonists on cocaine-induced reflexes in sleep-deprived rats. Separate groups of PSD rats received saline, D3 (U9919A; 0.75, 1.5 and 3 mg/kg) or D4 (L745870; 0.75, 1.5 and 3 mg/kg) antagonists prior to acute cocaine challenge. Results demonstrated that U9919A induced significant reduction in the number of animals that displayed erection and the frequency of erection at two smaller doses, while no significant difference was reported for the D4 receptor antagonist. Although our studies indicate that there is a relevant participation of D3 receptors in male sexual function, D4 receptors seem not to exert an essential role in this model.
Andersen
Monica L
ML
Department of Psychobiology, Universidade Federal de São Paulo, Escola Paulista de Medicina, São Paulo, Brazil. mandersen@psicobio.epm.br
Perry
Juliana C
JC
Tufik
Sergio
S
D000818:Animals; D003042:Cocaine / Q000494:pharmacology*; D018765:Dopamine Uptake Inhibitors / Q000494:pharmacology*; D005837:Genitalia, Male / Q000187:drug effects* / Q000378:metabolism*; D008297:Male; D010410:Penile Erection / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D050637:Receptors, Dopamine D3 / Q000187:drug effects* / Q000378:metabolism*; D050638:Receptors, Dopamine D4 / Q000187:drug effects* / Q000378:metabolism*; D012018:Reflex / Q000187:drug effects*; D012726:Sexual Behavior, Animal / Q000187:drug effects; D012892:Sleep Deprivation / Q000378:metabolism*
D018765:Dopamine Uptake Inhibitors; D050637:Receptors, Dopamine D3; D050638:Receptors, Dopamine D4; D003042:Cocaine