Segmental distribution of alpha-glucosidase, ornithine decarboxylase and polyamines in the human epididymis

Regional differences in the total activities of the epididymal secretory parameter, alpha-glucosidase, were demonstrated in the 20,000 g supernatants of human epididymal homogenates. A comparison of the enzymic activities in the supernatants and the washings from 12 one centimetre segments of human epididymides indicated an activity peak in segments 3-4 which appeared to be largely intracellular and which presumably reflects the acidic isoenzyme. A second peak in the caudal region, the segmental localization of which was more variable and differed in post-mortem and operation specimens, appeared to be primarily intraluminal. The activities of ornithine decarboxylase (ODC), the rate-limiting enzyme in the polyamine pathway, also exhibited regional differences with higher activities in relatively short segments in both caput and caudal portions. Corresponding alterations were also found in the tissue concentrations of the enzyme products, spermidine and spermine. The increased intracellular activities of ODC and alpha-glucosidase in the distal caput segments presumably reflect the transition of epithelium from the efferent to the epididymal ducts.