Semicarbazide-sensitive amine oxidase activity in rat aortic cultured smooth muscle cells

Metabolism of 5 microM benzylamine (BZ) by rat aortic cultured smooth muscle cells (SMC) is inhibited almost completely by 10(-3) M semicarbazide and 10(-6) M propargylamine, but is little affected by 10(-4) M and 10(-3) M pargyline and clorgyline, indicating BZ metabolism predominantly by the semicarbazide-sensitive amine oxidase (SSAO) previously characterized in rat aortic homogenates. Km values of 7-9 microM for BZ metabolism by SSAO in SMC cultures, indicate similar, if not identical properties, to the enzyme in the parent blood vessel.