Intercellular pathway of leucine catabolism in rat spermatogenic epithelium.
A unique intercellular pathway of leucine catabolism was observed in vitro in rat spermatogenic epithelium. Sertoli cells convert leucine via transmination into 4-methyl-2-oxovalerate, and spermatocytes and spermatids reduce exogenous 4-methyl-2-oxovalerate to 2-hydroxy-4-methylvalerate, which is then released by the spermatogenic cells. The NADH-dependent reduction of 4-methyl-2-oxovalerate could be catalysed by the male-germ-cell-specific lactate dehydrogenase isoenzyme LDH-C4 in the cytosol of the spermatogenic cells, concomitant with the NAD+-dependent conversion of exogenous lactate into pyruvate.
D000818:Animals; D002849:Chromatography, Gas; D004848:Epithelium / Q000378:metabolism; D005110:Extracellular Space / Q000378:metabolism; D066298:In Vitro Techniques; D007651:Keto Acids / Q000378:metabolism; D007930:Leucine / Q000378:metabolism*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012708:Sertoli Cells / Q000378:metabolism; D013091:Spermatogenesis; D013737:Testis / Q000378:metabolism*
D007651:Keto Acids; C013082:alpha-ketoisocaproic acid; D007930:Leucine