The interaction of aortic glycosaminoglycans and 3H-inulin endothelial permeability in cholesterol induced rabbit atherogenesis.

Male Dutch-belted rabbits were fed a pelleted 0.5% cholesterol diet for 8 weeks. A control group was maintained on basal pelleted diet for the same period of time. Prior to sacrifice both groups received i.v. 3H-inulin. Plasma and aortic sections were assayed for 3H-inulin activity. Aortic sections were also analyzed for glycosaminoglycan concentrations. A ratio of the aortic 3H-inulin activity to the plasma 3H-inulin activity was calculated and expressed as a permeability index. Mean plasma activity of 3H-inulin was significantly lower in the control group, suggesting increased aortic permeability in the cholesterol-fed animals. Glycosaminoglycan concentrations were significantly higher in the control group, and significant negative correlations were detected between glycosaminoglycan concentrations and permeability index in all animals. These findings are consistent with the hypothesis that sufficient glycosaminoglycan levels are important to maintaining the permeability characteristics of the endothelial layer.