Properties and functions of tissue-bound semicarbazide-sensitive amine oxidases in isolated cell preparations and cell cultures.

The demonstration of semicarbazide-sensitive amine oxidase (SSAO) activity in some freshly-dispersed cell preparations and in particular types of cells grown in culture, provides increasing opportunities for investigating the importance of SSAO in various aspects of cellular function. Assays of benzylamine and methylamine metabolism in homogenates of cultured cells have established clearly that SSAO is expressed in rat and pig vascular (aortic) smooth muscle cells, as well as in rat non-vascular (anococcygeus, trachea) smooth muscle, brown and white adipocytes. However, to date little or no SSAO activity has been detected in cultures of human vascular smooth muscle cells grown from blood vessels (e.g. umbilical artery) known to contain the enzyme, and the reason for this is not yet apparent. However, those cell cultures expressing SSAO are offering useful experimental models for studying biochemical and toxicological consequences upon cellular function which may result from the metabolism of various aromatic and aliphatic amines suggested to be possible physiological and xenobiotic substrates of the enzyme.