Differentiation between catalepsies induced by l-tetrahydropalmatine and by haloperidol and morphine
Abstract
By means of gel-permeable chromatography with Sephadex G-10 the brain DA and momovanillic acid (HVA) were isolated and then determined fluorospectrometrically. After ip l-tetrahydropalmatine (l-THP) 100 mg/kg in rats or iv 40 mg/kg in rabbits the HVA level in nucleus caudatus was elevated significantly. Thus, l-THP stimulated the activities of nucleus caudatus DA neurons.
Rats wereused in catalepsy experiment. l-THP (70 or 100 mg/kg, ip), morphine (20 or 30 mg/kg, ip) or haloperidol (0.13-1.0 mg/kg, ip) could, but d-THP (200 mg/kg, ip) could not induce catalepsies. Haloperidol-induced catalepsy could be antagonized selectively by ip scopolamine 5 mg/kg, and morphine-induced catalepsy by ip naloxone 1 mg/kg. On the other hand, l-THP-induced catalepsy was potentiated by ip aminoxyacetic acid (AOAA 10 mg/kg) which is well-known as an inhibitor of GABA-transaminase. Therefore, we deduce that the l-THP-induced catalepsy may be related with GABA-ergic system
Keywords:
Rats wereused in catalepsy experiment. l-THP (70 or 100 mg/kg, ip), morphine (20 or 30 mg/kg, ip) or haloperidol (0.13-1.0 mg/kg, ip) could, but d-THP (200 mg/kg, ip) could not induce catalepsies. Haloperidol-induced catalepsy could be antagonized selectively by ip scopolamine 5 mg/kg, and morphine-induced catalepsy by ip naloxone 1 mg/kg. On the other hand, l-THP-induced catalepsy was potentiated by ip aminoxyacetic acid (AOAA 10 mg/kg) which is well-known as an inhibitor of GABA-transaminase. Therefore, we deduce that the l-THP-induced catalepsy may be related with GABA-ergic system