A monkey model for mucoid vasculopathy.

Mucoid vasculopathy is a new vascular entity observed by the Author in autopsy material in Kerala, a southwest coastal state of tropical India. This non-atherosclerotic, non-inflammatory connective tissue disorder affects mainly arteries, veins, vasa-nervosum and fascial tissues. Characteristically, there are large deposits of acid mucopolysaccharide (glycosaminoglycan) material in the intima and media of arteries, accompanied by hyperplastic changes in cellular elements of the vessel wall and dystrophic changes in internal elastic laminae. There is secondary mineralization of elastic laminae and of medial mucoid material in some cases. To ascertain the role of diet in the aetiology of mucoid vasculopathy, groups of bonnet monkeys were fed protein-deficient normal carbohydrate, or protein-deficient high-carbohydrate tapioca (cassava) starch based diets or control diets of normal protein and carbohydrate for 3 or 5 months periods. The diet of the poorer sections in Kerala is deficient in protein and tapioca is the main source of carbohydrate. A generalised mucopolysaccharidosis and vasculopathy similar to the human condition and associated with some cardiomyopathic changes could be induced in the monkeys by protein deficient diets. These were enhanced both by ingestion of a high carbohydrate and by a longer experimental period. In order to exclude the effect of toxic factors which might be present in tapioca starch, experiments were repeated with corn starch as the carbohydrate: identical cardiovascular lesions were induced. The animal experiments established pivotal role for protein-deficiency in inducing mucoid vasculopathy with enhancement of degenerative cardiovascular lesions by ingestion of higher levels of carbohydrate in a protein-deficient state. This experimental study establishes a good animal model for mucoid vasculopathy.