Fructose and proteins in human semen

The aim of this study was to correlate human seminal fructose determinations by enzymatic UV method with protein content, using three different methods (Biuret, Lowry, Meulemans). On one hand, the incidence on fructose levels of partial deproteinization after treatment by perchloric acid was tested: the fructose levels values increased after deproteinization 14.1 +/- 3.7 versus 4.2 +/- 1.7 mMol/l. On the other hand, physiologically, semen proteolysis occurs for many hours after collection and concerns mainly low molecular weight proteins. No modifications were found in protid levels and fructose concentrations during the first four hours, at 20 degrees C. All these data seem to indicate a better linkage of fructose to the highest molecular weight proteins and might explain the absence of fructose rise during the first four hours.