The extra-gonadal sperm reserve (the sperm reserve in the vasa deferentia and the epididymides) was depleted in six donors by an average of 2·4 emissions per day during a 10-day depletion period. Daily sperm output (dso) was then estimated from the examination of one specimen a day for 24 days. During the dso period, specimen volume averaged 59% and sperm concentration per specimen 27% of that in the control or pre-depletion period. Sperm output per specimen and per week did not return to the levels of the pre-depletion period during a 156-day period (equal to three complete 52-day cycles of spermatogenesis and movement of spermatozoa through the duct system) after the completion of dso. At a frequency of fewer than five emissions per week, the greatest single influence on sperm numbers in the specimen is the size of the extra-gonadal sperm reserve. Daily sperm output, after the depletion of the extra-gonadal sperm reserve, may be used to estimate daily sperm production (dsp) by the testes. Changes in dso may be used to measure treatment effects on spermatogenesis. A practical experimental design is proposed for the analysis of factors and treatments affecting dsp in man.
If the inline PDF is not rendering correctly, you can download the PDF file here.