We have investigated the expression and localization of histidine decarboxylase (HDC, a key enzyme for histamine biosynthesis) in human skin by immunohistochemical analysis. HDC-immunoreactive cytokeratin 14-non immunoreactive cells were observed around basal layer epidermis healthy subjects patients with atopic dermatitis (AD). These did not express mast cell-tryptase but expressed tyrosinase ...

1. Concentrations of polyamines, amino acids, glycogen, nucleic acids and protein, and activities of ornithine decarboxylase and S-adenosylmethionine decarboxylase, were measured in livers from control, streptozotocin-diabetic and insulin-treated diabetic rats. 2. Total DNA per liver and protein per mg of DNA were unaffected by diabetes, whereas RNA per mg of DNA and glycogen per g of liver wer...

Histamine is formed by decarboxylation of the amino acid L-histidine, a process catalyzed by histidine decarboxylase (HDC) and can be inactivated either by methylation of the imidazole ring, catalyzed by histamine N-methyltransferase (HMT) or by oxidative deamination of the primary amino group, catalyzed by diamine oxidase (DAO). This chapter describes the enzymatic reactions and the properties...

Mature 53 kDa histidine decarboxylase (HDC) peptide is produced from a precursor 74 kDa peptide. The mechanism of specific cleavage by processing enzyme is unknown. Using the recombinant mouse 74 kDa HDC, we found that porcine pancreatic elastase specifically converted the inactive 74 kDa HDC to its active form of 53 kDa HDC.

The role of the intestinal mast cell system in the pathophysiology of postischaemic mucosal lesions is not understood. The present goals were to investigate the contributions of mast cells and mast cell-derived vasoactive mediators to mucosal injury caused by arterial occlusion. We evaluated the intestinal ischaemia-reperfusion-induced local morphological changes in mast cell-depleted anestheti...

We have examined the effects of exogenous and intrasynaptosomal histamine on the GABA transport in rat brain synaptosomes. Exogenous histamine had no effect on GABA uptake, but inhibited veratridine-evoked GABA release. GABA uptake was susceptible to the modification of histamine synthesis in synaptosomes. The increase of synaptosomal histamine level by incubation under conditions favouring his...

AND LILLIAN K. SCHNEIDER..................................... 181 The Consequences of Mutation during the Growth of Biochemical Mutants of Escherichia coli. III. The Inhibition of Histidine-independent Bacteria by Histidineless I3acteria in Aerated Cultures. FRANCIS ,J. RYAN AND LILLIAN K. SCHUCHARDT ................................... 191 The Consequences of Mutation during the Growth of Bioch...

Histamine is involved in different physiological and pathological responses, such as immune response, gastric acid secretion or neurotransmission, as either angiogenesis or cancer. Histidine decarboxylase (HDC) catalyzes the formation of histamine from histidine. HDC has been suggested as a new marker for neuroendocrine differentiation, inflammatory pathologies and several leukemia and highly m...

HDC (L-histidine decarboxylase), the enzyme responsible for the catalytic production of histamine from L-histidine, belongs to an evolutionarily conserved family of vitamin B6-dependent enzymes known as the group II decarboxylases. Yet despite the obvious importance of histamine, mammalian HDC enzymes remain poorly characterized at both the biochemical and structural levels. By comparison with ...