The effect of human growth hormone on the carbohydrate units in arterial basement membrane-like material.

OBJECTIVE: The present study focuses on the pathogenesis of the large vessel disease in diabetes. The arterial wall from diabetic individuals displays characteristic alterations of the extracellular matrix. Other observations show that the metabolism is changed with increased levels of growth hormone in diabetes. DESIGN: The effects of growth hormone on the carbohydrate composition in the basement membrane around the arterial smooth muscle cells were investigated. METHODS: Basement membrane material was obtained from cultures of smooth muscle cells by sonication and differential centrifugation after labeling with either [(3)H]glucose or [(3)H]glucosamine. The proportions of galactose, glucose, mannose, xylose, fucose and glucosamine were evaluated after addition of 45.45pmol/l human growth hormone. Also, the proportion of glycopeptides generated from the basement membrane was analyzed after fractionation on a combination of a Concanavalin A and a Pea Sepharose column. RESULTS: The proportion of galactose and glucose was changed, and the incorporation of [(3)H]glucosamine was reduced. The proportion of glycopeptides containing high mannose moities was increased as well as that of triantinary glycopeptides with internal fucose residues. CONCLUSION: The current in vitro data indicates that growth hormone may change the carbohydrate composition of the arterial basement membrane.