LSH-X and HBDH/LDH ratio in human semen

The enzymatic activities of lactate dehydrogenase (LDH) and alpha-hydroxybutyrate dehdyrogenase (HBDH) were measured in 87 semen samples. The highest values of these enzymes correspond to the specimens with greatest sperm density and motility. There was a positive correlation between the enzymatic parameters and sperm density and motility. There was a positive correlation between the HBDH/LDH ratio and the percent LDH-X. The estimation of the HBDH/LDH ratio, easily and rapidly done, can be a substitute for direct LDH-X estimations. The HBDH/LDH ratio greater than 1.0 that was noted in men with good sperm motility and normal sperm counts, could represent a reliable index of semen quality.