Proteoglycan: collagen interactions in dermatosparactic skin and tendon. An electron histochemical study using cupromeronic blue in a critical electrolyte concentration method.

Proteoglycans (PGs), stained for electron microscopy with Cupromeronic blue, were observed in skin and tendon from normal and dermatosparactic calves. Very frequently they (i.e. dermatan sulphate (DS) PGs) were seen arrayed orthogonally to the collagen fibrils, in the gap zone, usually at the d band, in both diseased and normal tissues. Where UO2(2+) staining showed regular and normal packing of collagen molecules, orthogonally located DS PGs were seen. No qualitative differences between controls and pathological tissues were identified, but quantitatively it appears likely that considerable areas of the surface of dermatosparactic skin collagen fibrils may be without associated PGs.