The purpose of this study was to investigate the effect of aortic hypoxia to the thrombogenisity, the collagen metabolism in aortic walls, and to the development of arteriosclerosis.
Experimental arteriosclerotic rabbits (A. S. R.) were induced by intermittent expausure to systemic hypoxia. After mechanical removal of perivascular tissue, aortic segments were incubated in the Eagle MEM medium. PGI2 release was quantitated by a radioimmunoassay for 6 keto PGF1α. The activity of proly-hydroxylase in aortic tissue was measured by the method of Peter kofsky's tritium release assay. The aortic hydroxyproline concentration was measured by Woessner's method.
Aortic PGI2 release in A. S. R. was deminished. The activity of prolylhydroxylase in aortic tissue was increased in A. S. R., so it was suspected that collagen synthesis was increased in A. S. R. However, there was no differences in aortic hydroxyproline concentrations between A. S. R. and normal rabbits.
Diminished aortic PGI2 release might reduce the defence mechanism against platelet deposition, and hyper thrombogenisity might occur in aortic walls. These changes, induced by hypoxia in vessel wall, appears to play an important role in the development of arteriosclerosis.
