Alterations in plasma semicarbazide-sensitive amine oxidase activity in hypertensive heart disease with left...

Semicarbazide-sensitive amine oxidase (SSAO) is found in various mammalian tissues, particularly in vascular smooth muscle cells, but also in plasma. It has been suggested that it plays an important role in vascular endothelial damage and in progression of atherosclerosis through conversion of endogenous amines into cytotoxic aldehydes, ammonia and hydrogen peroxide. In patients with diabetes mellitus and chronic heart failure, plasma activity appears to rise in parallel with disease severity.

Plasma SSAO and monoamine oxidase (MAO) activity was measured in 39 patients with hypertensive heart disease and left ventricular systolic dysfunction, in NYHA heart failure class II-IV, and compared to values in 89 controls. SSAO was found to be elevated in patients compared to controls (2.781 +/- 1.599 vs. 1.627 +/- 0.751 micromol/l/h; p = 0.000). Plasma MAO was also significantly increased in the patient group (3.837 +/- 1.899 vs. 3.077 +/- 1.559 (micromol/l/h; p = 0.018). No significant differences were seen between different NYHA classes, but class IV patients presented the highest SSAO activity. SSAO and MAO activity showed a trend for a positive correlation (R = 0.265; p = 0.092).

The finding of elevated plasma SSAO and MAO activity in congestive heart failure supports the hypothesis that amine oxidases may be involved in the pathogenesis of vascular endothelial damage.