title: In vitro inhibition of histamine metabolism in guinea pig lung by S-(-)-nicotine.
abstract: S-(-)-Nicotine competitively inhibits the metabolism of histamine to its N tau-methylated derivative in guinea pig lung homogenates. S-(-)-Nicotine exhibited a dissociation constant of the enzyme:inhibitor complex, Ki, of 9.4 X 10(-5) M compared with Km's for histamine and co-factor, S-adenosylmethionine, of 4.74 X 10(-5) M and 1.76 X 10(-5) M, respectively. This demonstrates the first reported involvement of nicotine in histaminergic mechanisms.
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D006168:Guinea Pigs; D006632:Histamine / Q000378:metabolism*; D006637:Histamine N-Methyltransferase / Q000037:antagonists & inhibitors; D066298:In Vitro Techniques; D007700:Kinetics; D008168:Lung / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D009538:Nicotine / Q000494:pharmacology*; D013237:Stereoisomerism
chemical_list: D009538:Nicotine; D006632:Histamine; D006637:Histamine N-Methyltransferase