Fructose, proteins and coagulation in human seminal plasma.

Fructose is produced and secreted by the seminal vesicles and it is believed to form tight bonds with certain proteins that are also of vesicular origin. Under normal conditions of liquefaction, fructose is totally dialyzable; however, blocking liquefaction by exposing semen to acidic conditions renders this sugar non dialyzable. Fructose therefore appears to play a role in the coagulation of semen. The formation of fructose-protein complexes may resolve physiological problems concerning osmotic pressure in the seminal vesicles: if all the fructose were present in free state, the osmotic pressure would be very high and incompatible with cell survival