Association of spermine and diamine oxidase activity with human spermatozoa.

Human spermatozoa, separated from the seminal plasma, contained substantial amounts of spermine, and also a distinct diamine oxidase (EC1.4.3.6) activity. Spermine, but not diamine oxidase activity, could be removed from the spermatozoa by washing the cells with buffers containing high concentrations of salts. Incubation of human spermatozoa in the presence of labelled spermine and partly purified amine oxidase from bovine blood gave rise to the formation of radio-active products that could not be removed from the spermatozoa by increasing the ionic strength. Similarly, partly purified diamine oxidase from human seminal plasma apparently catalysed the formation of labelled products from radioactive spermine that were more tightly bound to the spermatozoa than spermine itself.