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 vesse l 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 hormon e in diabetes. Design: The effects of growth hormone on the carbohydrate composition in th e basement membrane around the arterial smooth muscle cells were investigat ed. Methods: Basement membrane material was obtained from cultures of smooth mu scle cells by sonication and differential centrifugation after labeling wit h either [H-3]glucose or [H-3]glucosamine. The proportions of galactose, gl ucose, mannose, xylose, fucose and glucosamine were evaluated after additio n of 45.45 pmol/l human growth hormone. Also, the proportion of glycopeptid es 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 incor poration of [H-3]glucosamine was reduced. The proportion of glycopeptides c ontaining 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 cha nge the carbohydrate composition of the arterial basement membrane.