SPECIFIC INHIBITION OF SPERMATOZOAL ENERGY-METABOLISM BY OXIDIZED SPERMINE

Oxidized spermine, an iminoaldehyde [N,N′-bis(3-propionaldehyde)1,4-diaminobutanel inhibits the energy metabolism of human spermatozoa with striking specificity as compared with other mammalian cell types. Low concentrations of oxidized spermine virtually abolished the conversion of glucose to CO2 and lactate in human spermatozoa while in Ehrlich ascites-carcinoma cells, in human peripheral lymphocytes and in human vaginal minces, the iminoaldehyde caused little, if any, inhibition of glucose degradation. In contrast to oxidized spermine, some other aliphatic aldehydes with long carbon chain, which likewise were inhibitory to human spermatozoa, did not show any cell specificity depressing equally well the metabolism of all cell types tested. The inhibitory action exerted by oxidized spermine on human sperm metabolism could be prevented, but not reversed, with heparin. The latter compound, however, did not prevent the inhibition produced by other aliphatic aldehydes. Although the mechanism of inhibition by oxidized spermine, and other aliphatic aldehydes as well, is not completely clear, it possibly involves an interaction of the compounds with cell membranes, since no inhibition was found when cell free extracts of spermatozoa were used as the source of glycolytic enzymes. The idea that the inhibition by oxidized spermine was not entirely an unspecific detergent-like effect was supported by the finding that Triton X-100 depressed the glucose metabolism in Ehrlich ascites cells and human spermatozoa in a similar manner, while under the same conditions oxidized spermine, being strongly inhibitory to the sperm cells, failed to depress the glucose degradation by ascites cells. Oxidized spermine also inhibited the conversion of radioactive pyruvate to carbon dioxide in human sperm cells. © 1978.