Effect of CH-1243, a pyrido (1,2-a) pyrimidine derivative on the elevated activity of lysosomal enzymes of rabbit aorta and liver in experimental atherosclerosis

The effect of CH-123 (3-carbethoxy-6-methyl-1-9-(carboxy-methyl)-1-4-oxo-6,7,8,9-tetrahydro-4H-pyrid o(1,2a)pyrimidine) was investigated on the activity of 4 lysosomal enzymes: beta-glucuronidase, beta-galactosidase, N-acetyl-beta-glucosaminidase and Acid Phosphatase obtained from aortic smooth muscle and liver cells of rabbits. Animals were fed on a 2% Cholesterol diet for 4 weeks and used an experimental atherosclerotic group. In drug-treated groups, after 4 weeks of Cholesterol feeding the diet was changed to regular food and the Animals were treated daily either with 50 mg/kg CH-123 or with 250 mg/kg Clofibrate. The postnuclear supernatant of homogenates of liver and aortic cells was isolated, lysosomes were fractionated by sucrose density gradient centrifugation, and the activity of Enzymes was measured. In cholesterol-fed Animals the enzyme activities of aorta and liver was 3-5 times higher than in the control, i.e. in the group of rabbits fed regular food. On Clofibrate treatment the enzyme activities were 2-3 times higher, but on treatment with CH-123, they were only 1.2-1.8 times above the control. Experiments suggest that CH-123 treatment suppresses the elevated lysosomal marker enzyme activities in aortic and liver cells of atherosclerotic Animals.