The acute effects of methamphetamine, amphetamine and p-chloroamphetamine on the cortical serotonergic system of the rat brain: evidence for differences in the effects of methamphetamine and amphetamine.
Cortical tryptophan hydroxylase (TPH) activity was reduced 3 h after a 10 or 15 mg/kg i.p. dose of either amphetamine (AMP), methamphetamine (METH), or p-chloroamphetamine (PCA). These injections of METH or PCA also decreased cortical serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) concentrations; none of the four doses of AMP decreased indoleamine concentrations. The time course of the effects following a 15 mg/kg dose of each amine was also different. Cortical TPH activity was reduced by all three amines for periods up to 24 h, whereas only METH and PCA significantly decreased 5-HT and 5-HIAA concentrations for long periods. These data suggest that each of the amphetamines may inhibit TPH activity, whereas only METH and PCA produced long-lasting decreases in indoleamine concentrations, reflecting either varying degrees of toxicity or differential effects of AMP on enzyme activity and neurotransmitter concentrations.
M A
MA
Peat
P F
PF
Warren
C
C
Bakhit
J W
JW
Gibb
D000661:Amphetamine / Q000494:pharmacology*; D000662:Amphetamines / Q000494:pharmacology*; D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects* / Q000201:enzymology; D002851:Chromatography, High Pressure Liquid; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D008297:Male; D008694:Methamphetamine / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000502:physiology*; D013997:Time Factors; D014365:Tryptophan Hydroxylase / Q000037:antagonists & inhibitors; D010133:p-Chloroamphetamine / Q000494:pharmacology*
D000662:Amphetamines; D012701:Serotonin; D008694:Methamphetamine; D006897:Hydroxyindoleacetic Acid; D010133:p-Chloroamphetamine; D000661:Amphetamine; D014365:Tryptophan Hydroxylase