Plasma semicarbazide-sensitive amine oxidase in human (patho)physiology.
Semicarbazide-sensitive amine oxidases (SSAO) are widely distributed enzymes, with as yet not fully elucidated functions and roles, present in many tissues but also circulating in plasma. The enzyme also functions as an adhesion molecule, the vascular adhesion protein-1. In healthy humans, plasma SSAO activity is constant from birth until 16 years of age, when it drops to lower values, gradually increasing again at advanced ages. When measuring SSAO activity, care should be taken to ensure proper preparation and storage conditions, and it should be realized that quite a few drugs unintentionally are good inhibitors, and sometimes even substrates, of SSAO. Under normal conditions SSAO activity is constant and inter-individual variation is small. In various pathophysiological conditions plasma SSAO activities are increased, most notably in diabetes mellitus (both type I and type II), in congestive heart failure and in cirrhotic liver inflammation. In patients with other vascular and inflammatory diseases plasma SSAO is normal, while it is low in children with congenital lung diseases. Interpretation of these changes is speculative, since source and regulation of plasma SSAO are as yet unknown. However, in two situations where the disease-causing process was ended (transplantation, delivery), plasma SSAO returned to normal. Many questions remain to be answered.
Boomsma
Frans
F
Department of Internal Medicine, Rm. L-276, Erasmus MC, Dr. Molewaterplein 40, 3015 GD Rotterdam, The Netherlands. f.boomsa@erasmusmc.nl
Bhaggoe
Usha M
UM
van der Houwen
Angelique M B
AM
van den Meiracker
Anton H
AH
D006631:Amine Oxidase (Copper-Containing) / Q000097:blood*; D003920:Diabetes Mellitus / Q000201:enzymology; D006333:Heart Failure / Q000201:enzymology; D006548:Hernia, Diaphragmatic / Q000201:enzymology; D065630:Hernias, Diaphragmatic, Congenital; D006801:Humans; D007249:Inflammation / Q000201:enzymology; D012663:Semicarbazides / Q000494:pharmacology*
D012663:Semicarbazides; D006631:Amine Oxidase (Copper-Containing)