Quantitation of collagen - proteoglycan interaction in tissue sections.

Since the dye Sirius Red reacts with the basic groups of collagen, and it is possible to hydrolyze the proteoglycans bound to collagen by enzymatic digestion, a method was developed to quantitate the collagen-proteoglycan interaction in tissue sections. The method consists of measuring, with a spectrophotometer, the amount of dye bound to control and papain-digested tissue sections. The difference observed between the results obtained in control and digested sections is considered to be due to the unmasking of basic groups of collagen originally bound to proteoglycans. The initial results show a variability of this interaction in different tissues. They also suggest a reduction of collagen-proteoglycan interaction in atherosclerotic lesions.