Cystathionine synthase in rat brain: Regional and time-of-day differences and their metabolic implications
✍ Scribed by Randall Lee Kohl; W. B. Quay
- Publisher
- John Wiley and Sons
- Year
- 1979
- Tongue
- English
- Weight
- 477 KB
- Volume
- 4
- Category
- Article
- ISSN
- 0360-4012
No coin nor oath required. For personal study only.
✦ Synopsis
Jn relation t o concern for probable interrelations of cystathionine synthase (CS, EC 4.2.1.2 1) and methionine, one-carbon, and 5-hydroxytryptamine metabolism, we have investigated tissue and time-of-day differences in CS activity in the laboratory rat under standardized conditions. Liver, kidney, and pancreas had highest C S activities; nine regions of the CNS had mean activities ranging from 4.5% (lumbosacral cord) t o 24.5% (hypothalamus) of mean hepatic activity; pituitary and adrenal glands lacked detectable CS activity. Although significantly lower CS activity occurred in liver (& 9"?> P < 0.050) and kidney ($ 13%, P < 0.025) during the interval two hours before t o two hours after the daily onset of darkness, no significant changes were found in hypothalamus, cerebellum, or medulla oblongata. Regional CNS differences in CS activity appeared t o be without correlation in relation t o published data on relative contents of 5-hydroxytryptamine, tryptophan 5-hydroxylase (EC 1.14.16.4), 5,lO-methylene reductase (N5-methyltetrahydrofolate-NAD-oxidoreductase, (EC 1.1.1.78), or 5-methyltetrahydrofolate. Therefore, among CNS regions examined, a critical deficiency in ability to metabolize a honiocysteine load is considered t o be unlikely under normal conditions.