Effects of the antidepressant drugs clomipramine and mianserin on tryptophan hydroxylase activity in the rat brain, measured at two points in the light/dark cycle.
Tryptophan hydroxylase activity has been measured in synaptosomal preparations from rat brain. A significant circadian variation in enzyme activity was apparent in corpus striatum, (p < 0.001), brainstem and cortex (p < 0.01). A single dose of clomipramine or mianserin (20 mg/kg) had no effect on brainstem enzyme activity measured at mid-light or mid-dark. Chronic administration (7.5 mg/kg i.p. twice daily for 2 weeks) of either clomipramine or mianserin significantly increased enzyme activity. There was no significant difference between the drug effects measured at mid-light or mid-dark.
Sinei
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Pharmacology Group, School of Pharmacy and Pharmacology, University of Bath, England.
Redfern
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D000704:Analysis of Variance; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000201:enzymology* / Q000502:physiology; D001933:Brain Stem / Q000201:enzymology; D002540:Cerebral Cortex / Q000201:enzymology; D002940:Circadian Rhythm; D002997:Clomipramine / Q000494:pharmacology*; D003342:Corpus Striatum / Q000201:enzymology; D003624:Darkness; D007700:Kinetics; D008027:Light; D008297:Male; D008803:Mianserin / Q000494:pharmacology*; D009928:Organ Specificity; D051381:Rats; D017208:Rats, Wistar; D014365:Tryptophan Hydroxylase / Q000378:metabolism*
D008803:Mianserin; D014365:Tryptophan Hydroxylase; D002997:Clomipramine