COLLAGEN-SYNTHESIS MARKERS AND MATRIX METALLOPROTEINASES-2 (MMP-2) AND METALLOPROTEINASES-9 (MMP-9) IN THE SUCTION BLISTER FLUID AND SERUM OF JUVENILE DIABETIC-PATIENTS

In diabetes, various connective tissue alterations have been noted in the skin, such as thickening of the dermis and changes in the basement membranes. The mechanisms behind these changes are not known. In the present study, skin thickness and markers of collagen synthesis and de gradation were studied in 17 male, juvenile diabetic patients and in 1 1 healthy, male controls. As markers of collagen synthesis, C-propepti des and N-propeptides of type I procollagen (PICP and PINP) and N-prop eptides of type III procollagen (PIIINP) were measured both from sucti on blister fluid and serum. As markers of collagen degradation, the ma trix metalloproteinases MMP-2 (72 kDa gelatinase) and MMP-9 (92 kDa ge latinase) were assayed by the zymography method from the blister fluid s and serum. No marked changes could be found in the skin thickness of the diabetic patients compared to the controls when the A-scan ultras ound technique was used. In general the concentrations of the collagen propeptides and the matrix metalloproteinases were remarkably similar In the diabetic patients and the controls in both the suction blister Fluid and the serum. Interestingly, the concentrations of PINP in the blister fluid in the diabetic patients with long established disease were lower than those in the controls and the PICP/PINP ratio was ther efore significantly higher (p < 0.05) in these patients than in the co ntrols. This may be due to either a rate of PINP into the blister cavi ty. Since the ratio of PICP/PINP was not changed to the same extent in the serum as in the blister fluid, there is probably no generalized c leavage defect of procollagens present in diabetes.