p-Dimethylaminobenzaldehyde-reactive substances in tail tendon collagen of streptozotocin-diabetic rats: temporal relation to biomechanical properties and advanced glycation endproduct (AGE)-related fluorescence.
In the present work, pepsin digests of tail tendons from streptozotocin-diabetic rats were found to contain material that reacted rapidly at room temperature with p-dimethylaminobenzaldehyde (Ehrlich's reagent) to give an adduct with an absorbance spectrum characteristic of the Ehrlich chromogen of pyrrolic nature determined in ageing collagens. A significant correlation of the Ehrlich adduct with tendon mechanical strength and collagen fluorescence characteristic of advanced glycation endproducts was observed. Collagen content of the Ehrlich-positive material was found to be significantly elevated in tendons of diabetic rats compared with age-matched healthy controls. The results indicate that the p-dimethylaminobenzaldehyde-reactive pyrrole moieties may contribute to the increased cross-linking of diabetic matrix collagen. Profound inhibitory effect of aminoguanidine was observed, underlining the role of non-enzymatic mechanisms of advanced glycation in pyrrolisation and cross-linking of collagen exposed to hyperglycaemia. It is hypothesised that quantification of the p-dimethylaminobenzaldehyde-reactive material in matrix collagen may provide a tissue measure of integrated hyperglycaemia over prolonged periods of time. Further research is to assess the significance of p-dimethylaminobenzaldehyde-reactive substances in diabetic collagen tissues and to reveal their relationship to enzyme-mediated physiological pyrrolisation of ageing collagens.
Stefek
M
M
Institute of Experimental Pharmacology, Slovak Academy of Sciences, Dubravska cesta 9, 842 16, Bratislava, Slovakia. exfastfk@savba.sk
Gajdosik
A
A
Gajdosikova
A
A
Krizanova
L
L
D000818:Animals; D001547:Benzaldehydes; D003094:Collagen / Q000737:chemistry* / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000378:metabolism*; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000494:pharmacology; D017127:Glycation End Products, Advanced / Q000032:analysis*; D006146:Guanidines / Q000494:pharmacology; D007202:Indicators and Reagents; D008297:Male; D010434:Pepsin A; D011758:Pyrroles / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar; D013053:Spectrophotometry; D013314:Stress, Mechanical; D013623:Tail; D013710:Tendons / Q000737:chemistry* / Q000378:metabolism; D013997:Time Factors
D001547:Benzaldehydes; D004791:Enzyme Inhibitors; D017127:Glycation End Products, Advanced; D006146:Guanidines; D007202:Indicators and Reagents; D011758:Pyrroles; D003094:Collagen; D010434:Pepsin A; C004479:pimagedine; C510241:p-dimethylaminobenzaldehyde