Involvement of bicuculline-insensitive receptors in the hypothermic effect of GABA and its agonists.
GABA, delta-aminovaleric acid (DAVA) and sodium valproate (VPA) decrease core temperature in conscious rats. Bicuculline increases GABA-induced hypothermia, does not modify DAVA (250 mg/kg) and VPA (100 and 400 mg/kg) hypothermia and antagonizes initial hypothermia by DAVA (1000 mg/kg) and VPA (200 mg/kg) and late hypothermia by DAVA (500 mg/kg) and VPA (200 mg/kg). Picrotoxin increases late hypothermia by GABA (250 mg/kg) and VPA (400 mg/kg), but decreases initial hypothermia by VPA (200 mg/kg). Pentylenetetrazol increases variably GABA-induced hypothermia, inhibits early early hypothermia by DAVA and increases hypothermia induced by VPA (400 mg/kg). We conclude that GABA and GABA-agonists (DAVA and VPA) may induce hypothermia partly mediated by activation of bicuculline-insensitive GABA-receptors.
D000596:Amino Acids / Q000494:pharmacology; D021542:Amino Acids, Neutral; D000818:Animals; D001640:Bicuculline / Q000494:pharmacology*; D001831:Body Temperature / Q000187:drug effects*; D004347:Drug Interactions; D005260:Female; D007035:Hypothermia / Q000139:chemically induced; D010433:Pentylenetetrazole / Q000494:pharmacology; D010852:Picrotoxin / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011963:Receptors, GABA-A / Q000187:drug effects*; D013997:Time Factors; D014635:Valproic Acid / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology* / Q000502:physiology
D000596:Amino Acids; D021542:Amino Acids, Neutral; D001640:Bicuculline; D010433:Pentylenetetrazole; D010852:Picrotoxin; D011963:Receptors, GABA-A; D014635:Valproic Acid; D005680:gamma-Aminobutyric Acid; C013809:5-aminovaleric acid