Transaminase in Human Semen

Abstract

Determinations of aspartate and alanine aminotransferase activity in human semen were carried out by the spectrophotometric and colorimetric methods. It was found that the occurrence of interfering substances in semen makes the spectrophotometric method unsuitable without prior partial purification of the enzyme. The mean activity determined colorimetrically in 417 samples of human semen was 320 Sigma-Frankel units/ml (s.e.m. \m=+-\8,range 10 to 1070) for aspartate aminotransferase and 30 units/ml (s.e.m. \ m=+-\ 3, range 0 to 97, n = 40) for alanine aminotransferase. As regards aspartate aminotransferase, the activity of this enzyme was highest at +60\s=deg\ C. Pyridoxal phosphate increased the activity, particularly if added to semen samples with initially low activity. Gel electrophoresis of seminal plasma showed one band migrating towards the anode. However, in homogenized spermatozoa the bulk of enzyme migrated towards the cathode and only a weak band could be demonstrated on the side of the anode.

Relationship between biochemical constituents of fish semen and fertility: the effect of short-term storage

“…Which factor is responsible for the rather high amount of apoenzyme in spermatozoa remains to be established. The high stimulation of semen AspAT was observed for human and farm animals semen (Elliason 1967;. The percentage of increase upon AspAT stimulation by PLP during the semen storage is additional evidence for spermatozoan origin of the increased activity.…”

“…There are two isoenzymes of aspartate aminotransferase in mammalian semen (Elliason 1967;Mortimer et al 1988;Ciereszko and Strzezek 1989), cytoplasmic and mitochondrial. The former one is easily liberated from spermatozoa to seminal plasma (Ciereszko et al 1990).…”