The influence of L-arginine on biomechanical parameters of native and nonenzymatically glycated rat tail tendons.

Rat tail tendons from animals of an age range from 35 days to 900 days were glycated using different glucose concentrations. After nonenzymatic glycation the biomechanical properties of tendons from young rats approached that of old tendons. In tendons from old animals the glucose incorporation was significantly lower than in young rat tail tendons. Addition of L-arginine to the glucose solution reduced the incorporation of glucose especially in young rats. The concentration of early glycation products and of advanced glycation end products were measured via affinity chromatography on boronic acid agarose and relative fluorescence per collagen content respectively. Both parameters were significantly reduced by an addition of 10 mmol/l arginine. Biomechanical changes due to glycation were partially reversed. Incubation of rat tail tendons in L-arginine in the absence of glucose caused a dose dependent binding of the amino acid mainly to the proteoglycan matrix. High concentrations of L-arginine induced pronounced biomechanical alterations contrary to the action of glucose. The biomechanical effect of L-arginine is compared to the action of Na+ and Ca2+ and discussed on the basis of a structural model of the proteoglycan matrix. Incubation of already glycated rat tail tendons with L-arginine caused a reduction of the elastic stress component This effect was diminished by increasing the preincubation interval with glucose. The equilibrium values of the elastic fraction were achieved after approximately five days incubation with the amino acid.