Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P15088 (mast cell)
 14,925 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tryptophan hydroxylase-immunopositive (TPH-I) but not serotonin-I nerve fibers were observed in the rat dura mater. This tissue also contained numerous serotonin and TPH-I mast cells. The TPH appeared to be located in granules and/or enclosed in a juxta-nuclear organite. Westernblots showed that the TPH located in the dura mater is similar to the TPH of pineal gland but different from raphe TPH. According to the animal, both nerve fiber and mast cell TPH immunoreactivity was highly variable in intensity and in number of labelled elements. This variability might be due to the complex regulatory mechanisms of TPH as indicated by the presence of two types of mast cells.
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PMID:Tryptophan hydroxylase can be present in mast cells and nerve fibers of the rat dura mater but only mast cells contain serotonin. 771 96

Tryptophan hydroxylase requires Fe2+ for in vitro enzyme activity. In this study, the intracellular activity of tryptophan hydroxylase was assessed by applying 3-hydroxybenzylhydrazine (NSD-1015), an inhibitor of aromatic l-amino acid decarboxylase, to monolayer cultures of RBL2H3 cells, a serotonin producing mast cell line. The effect of manipulating intracellular 'free' iron levels on enzyme activity was analyzed by administration of iron chelators. Desferrioxamine (DFO) suppressed the intracellular enzyme activity. Salicylaldehyde isonicotinoyl hydrazone (SIH) also suppressed enzyme activity, but stimulated it when administered in the Fe-bound form. Hemin also stimulated enzyme activity, which progressively increased over several hours to more than sixfold the initial level. DFO and SIH inhibited the hemin stimulatory effect when administered simultaneously with hemin. Both suppression and stimulation with these chelators took place without a significant decrease or increase in the amount of enzyme. These results indicate that there was an inadequate supply of Fe2+ in the cells to support full activity of tryptophan hydroxylase.
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PMID:Iron dependence of tryptophan hydroxylase activity in RBL2H3 cells and its manipulation by chelators. 1021 90