TYPE-VI COLLAGEN IN GLOMERULI OF SHORT-TERM AND LONG-TERM EXPERIMENTAL DIABETIC RATS

Type VI collagen was revealed by high-resolution immunocytochemistry i n renal glomeruli from short-and long-term streptozotocin-injected hyp erglycaemic rats and from their age-matched normoglycaemic controls. T he labellings obtained over the glomerular basement membrane and the m esangial matrix were assessed by quantitative evaluations. The labelli ngs over the glomerular basement membrane were low and sparse in the y oung normoglycaemic animals but became consistent and increased in int ensity with age and in both the short-and long-term diabetic animals. For the mesangial matrix, this was labelled more systematically, and i ts intensity increased with age and in the short-term hyperglycaemic a nimals. For the long-term hyperglycaemic animals, the intensities of l abelling resembled those of their age-matched controls. These results indicate that type VI collagen appears to be a minor constituent of th e extracellular matrix of the rat glomeruli, rather concentrated in th e mesangial area in the young control animal. Concomitant with the gen eral modifications of the extracellular matrix occurring with age and diabetes, this component increases, but apparently not with the length of the hyperglycaemic state. (C) 1998 Chapman & Hall.