title: High doses of oxytocin cause sedation and low doses cause an anxiolytic-like effect in male rats.
abstract: The aim of the present investigation was to explore dose relationships for effects of oxytocin on spontaneous motor activity in the rat. Oxytocin in doses from 1-1000 micrograms/kg was given SC to male Sprague-Dawley rats, and spontaneous motor behavior was measured by means of photocell-operated open-field observations. In the rats treated with low doses of oxytocin (1-4 micrograms/kg), there was a decrease in peripheral locomotor activity. With increasing doses (250-1000 micrograms/kg), there were clear signs of sedative effects as indicated by a suppression of locomotor activity and rearing. The time course for the effect of oxytocin on peripheral activity (1 microgram/kg) and rearing (1 mg/kg) was tested. A maximal effect was obtained within 1 h and, thereafter, the behavior gradually returned to normal within 24 h. This spectrum of effects caused by oxytocin was similar to that of midazolam but different from that induced by raclopride.
authors: Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
authors: K
authors: K
authors: Uvnäs-Moberg
authors: S
authors: S
authors: Ahlenius
authors: V
authors: V
authors: Hillegaart
authors: P
authors: P
authors: Alster
mesh_terms: D000818:Animals; D014151:Anti-Anxiety Agents / Q000008:administration & dosage / Q000494:pharmacology*; D001522:Behavior, Animal / Q000187:drug effects; D018492:Dopamine Antagonists / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000494:pharmacology*; D007279:Injections, Subcutaneous; D008297:Male; D008874:Midazolam / Q000494:pharmacology; D009043:Motor Activity / Q000187:drug effects; D010121:Oxytocin / Q000008:administration & dosage / Q000494:pharmacology*; D020891:Raclopride; D051381:Rats; D017207:Rats, Sprague-Dawley; D012457:Salicylamides / Q000494:pharmacology
chemical_list: D014151:Anti-Anxiety Agents; D018492:Dopamine Antagonists; D006993:Hypnotics and Sedatives; D012457:Salicylamides; D020891:Raclopride; D010121:Oxytocin; D008874:Midazolam