Plasma glucosamine and galactosamine in ischemic heart disease

Because of the importance of glycosaminoglycans and glycoproteins in the pathogenesis of atherosclerosis, the hexosamine concentrations of plasma were determined in 28 male survivors of acute myocardial infarction and in 50 healthy males aged 30-60 years. Glucosamine and galactosamine were determined by ion-exchange chromatography of hydrolyzed whole plasma and hydrolyzed deproteinized plasma. Considerably higher plasma levels of non-protein-bound hexosamine (500 nmol/ml) and lower levels of protein-bound hexosamines (3770 nmol/ml) were observed in the ischemic heart disease group, compared with the plasma levels of non-protein-bound hexosamine (320 nmol/ml) and protein-bound hexosamine (4260 nmol/ml) of the control group. This difference is due to changes in glucosamine concentration. The galactosamine concentration is similar in the two groups. The ratio of non-protein-bound to protein-bound hexosamines in patients is about twice as high as the ratio found in controls. The glucosamine/galactosamine ratio of protein-free plasma is significantly higher in patients (12.1) than in controls (8.3). These changes in plasma hexosamines correlate with increased plasma homocysteine, cholesterol, and triglycerides observed in the patient group. The findings show that characteristic quantitative and qualitative changes in plasma hexosamine levels accompany atherosclerosis. Determination of these substances may be helpful in diagnosis and management of patients with atherosclerosis.