Effects of thyrotropin-releasing hormone, oxytocin, and prolactin on thiopenthal-induced narcosis in rats.
Neuropeptides that may induce behavioral activation--thyrotropin-releasing hormone (TRH), oxytocin (OXY), and prolactin (PRL)--were tested on thiopenthal-induced narcosis after IV administration in male rats. TRH caused a significant shortening of sleeping time at the doses of 3 and 5 mg/kg, but did not change this parameter at lower doses. Oxytocin was effective at all doses tested (200, 300, and 400 micrograms/kg). Prolactin also shortened sleeping time at the doses of 0.2 and 1 mg/kg administered IV, slightly increasing it at the dose of 5 mg/kg. These results indicate that various neuropeptides are capable of reducing the duration of thiopenthal-induced sleep in rats.
Drago
F
F
Institute of Pharmacology, University of Catania Medical School, Italy.
Mauceri
F
F
Fidilio
M
M
Cavaliere
S
S
Pulvirenti
L
L
Foti
F
F
D000818:Animals; D007275:Injections, Intravenous; D008297:Male; D010121:Oxytocin / Q000494:pharmacology*; D011388:Prolactin / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012890:Sleep / Q000187:drug effects*; D013874:Thiopental / Q000494:pharmacology*; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology*
D010121:Oxytocin; D013973:Thyrotropin-Releasing Hormone; D011388:Prolactin; D013874:Thiopental