Tryptophan availability, central serotonergic function and methionine sulphoximine-induced convulsions.
A convulsant dose (100 mg/kg) of l-methionine-RS-sulphoximine (MSO) produced temporally correlated decreases in central 5-hydroxytryptamine (5-HT) and plasma and brain tryptophan (TRY) concentrations in C57BL/6J mice. In contrast, a subconvulsant dose of MSO (50 mg/kg) had no effect on central 5-HT levels and only decreased brain tryptophan at one time-point after its administration. The pattern of findings suggests that the decrease in central 5-HT levels resulting from a convulsant dose of MSO is related to an impairment in 5-HT synthesis resulting from a restriction of tryptophan availability. Administration of 25 mg/kg and 100 mg/kg doses of l-tryptophan with convulsant doses of MSO significantly increased seizure latency. It is suggested that the central 5-HT system modulates the expression of MSO-induced seizures.
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008717:Methionine Sulfoximine / Q000633:toxicity*; D051379:Mice; D008810:Mice, Inbred C57BL; D012640:Seizures / Q000139:chemically induced*; D012701:Serotonin / Q000502:physiology*; D013997:Time Factors; D014364:Tryptophan / Q000378:metabolism* / Q000494:pharmacology
D008717:Methionine Sulfoximine; D012701:Serotonin; D014364:Tryptophan