Enzymatic histamine degradation by human skin.
1. Degradation of histamine by homogenized human skin in vitro, in the presence of the cofactor S-adenosyl methionine, indicates the presence of the histamine metabolizing enzyme histamine-N-methyl transferase in human skin. Under the experimental conditions described, no significant histamine degradation by diamine oxidase was observed. 2. The enzyme activity is temperature-sensitive with an optimum at 37 degrees C. The enzyme is stable in in intact excised skin at -20 degrees C, but unstable in homogenized skin at this temperature. 3. Little or no enzyme activity is present in mid- or deep dermis, but the distribution of the enzyme between superficial papillary dermis and epidermis is uncertain. 4. The presence of a potent histamine degrading mechanism raises the possibility that histamine-N-methyl transferase activity may be an important modulating factor in histamine-mediated skin disorders.
D002855:Chromatography, Thin Layer; D004817:Epidermis / Q000201:enzymology; D005260:Female; D006146:Guanidines / Q000494:pharmacology; D006632:Histamine / Q000378:metabolism*; D006637:Histamine N-Methyltransferase / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D012436:S-Adenosylmethionine / Q000494:pharmacology; D012867:Skin / Q000187:drug effects / Q000201:enzymology*; D013696:Temperature
D006146:Guanidines; D012436:S-Adenosylmethionine; D006632:Histamine; D006637:Histamine N-Methyltransferase