Studies on lung N-methyltransferases, a pharmacological approach.
Phenylethanolamine N-methyltransferase (PNMT) was identified as the primary, high affinity N-methylating enzyme for phenylethanolamine (PEA) in rat, dog and Rhesus monkey lung. Human and rabbit lung, however, do not contain this enzyme but possess a more non-specific or general N-methyltransferase with a relatively low affinity for PEA and for which beta-phenethylamine (beta-PE) is also a substrate. The former but not the latter enzyme is markedly inhibited by micromolar concentrations of the PNMT antagonist, SK & F 64139. This evidence indicates that certain species differences exist for the enzyme system(s) available for the N-methylation of phenethylamine-type compounds in pulmonary tissue.
D000818:Animals; D004983:Ethanolamines / Q000378:metabolism; D066298:In Vitro Techniques; D007700:Kinetics; D008168:Lung / Q000201:enzymology* / Q000648:ultrastructure; D008253:Macaca mulatta; D008297:Male; D008780:Methyltransferases / Q000378:metabolism*; D010627:Phenethylamines / Q000378:metabolism; D051381:Rats; D013045:Species Specificity; D013347:Subcellular Fractions / Q000378:metabolism
D004983:Ethanolamines; D010627:Phenethylamines; D008780:Methyltransferases