Metabolism of glycerol by mature boar spermatozoa

Summary. Mature boar spermatozoa oxidized glycerol to carbon dioxide in the absence of any detectable activity of glycerol kinase. With triosephosphate isomerase and glyceraldehyde-3-phosphate dehydrogenase inhibited by the presence of 3-chloro-1-hydroxypropanone (CHOP), dihydroxyacetone phosphate accumulated in incubates when glycerol-3-phosphate was the substrate, but not when it was glycerol. Both dihydroxyacetone and glyceraldehyde could be used as substrates; in the presence of CHOP, dihydroxyacetone phosphate and fructose-1,6-bisphosphate accumulated when dihydroxyacetone was the substrate, but not when it was glyceraldehyde. The metabolic pathways glycerol→glyceraldehyde→glyceraldehyde 3-phosphate and dihydroxyacetone→dihydroxyacetone phosphate have been shown to operate in these cells. Keywords: glycerol; glycerol kinase; glyceraldehyde; dihydroxyacetone; spermatozoa; boar