Total Testis Volume Research Articles

Histological Changes in the Testis of the Domestic Fowl After Adenohypophysectomy

Twenty-two cockerels were adenohypophysectomized by the improved transbuccal approach to observe histological changes in the testis during 60 postoperative days. Total adenohypophysectomy induced a collapse of spermatogenic cells and a decrease in the diameter of seminiferous tubules, accompanied by a rapid decrease in testicular weight. The patterns of degeneration of various spermatogenic cells were different from each other. Spermatozoa and spermatids were detached from the epithelium by day 5, spermatocytes by day 10, and more than half of spermatogonia by day 20 after the operation. Sertoli cells reduced their cytoplasmic processes on day 3 but still retained their height to sustain an indented form of epithelium between days 3 and 10, when most spermatogenic cells were disengaged from the epithelium. Sertoli cells were never sloughed off into the lumen.On and after day 20, seminiferous epithelium was monolayered, consisting of atrophied Sertoli cells with small sized nuclei and spermatogonia. Interstitial cells tended to agglomerate and swell from day 20 after the operation, then reached the maximum on day 60. Interstitium occupied more than 30% of estimated total volume of testis from day 20 onward. According to the observation on day 30, the degree of degeneration of seminiferous tubules in later stages depended on the location within the testis. The network of cytoplasmic processes of Sertoli cells persisted in the central but not in the peripheral region.

STRUCTURAL COMPOSITION OF SHORTHORN BULL TESTES AND DAILY SPERMATOZOA PRODUCTION AS DETERMINED BY QUANTITATIVE TESTICULAR HISTOLOGY

The structural composition of the testes, the sperm output, and the daily sperm production were determined in seven 18-month-old Shorthorn bulls. The testicular components classified composed the following percentages of the total testis volume: spermatogonium nuclei,.62%; primary spermatocyte nuclei, 4.57%; secondary spermatocyte nuclei,.16%; spermatid nuclei, 3.52%; spermatozoa,.34%; tubular cytoplasm, 57.79%; lumen, 4.67%; basement membrane, 2.60%; intertubular space, 23.63%; and Sertoli cells, 2.04%. The seminiferous tubules made up 76.4% of the testis volume. It was estimated that the testes contained on the average 1630 m (range 960–2240 m) of seminiferous tubules. The tunica albuginea comprised 12.8% of the testis weight.Three procedures are described for measuring daily sperm production from quantitative testicular histology, and the results obtained with Shorthorn bull testes are presented. The limitations of the three procedures are discussed. It was estimated that 18-month-old Shorthorn bulls produced 5.3 × 109 sperm per day. This represented a production of 16.9 million sperm per gram of testis per day. Within a given species sperm production appears to be primarily a function of testis size. The seven bulls averaged 2.7 × 109 sperm per ejaculate when semen samples were collected every other day with an electroejaculator. This represented about 25% of the sperm production by the testes.

Seasonal cycles of the interstitial cells in the testis of the horned toad (Phrynosoma solare). Seasonal variations in the number and morphology of the interstitial cells and the volume of the interstitial tissue

AbstractA histological study has been made of a series of Phrynosoma testes taken at frequent intervals throughout the year. As it was important to differentiate between the amount of interstitial tissue and the number of cells, it was necessary to take into account the percentage of tissue, total testis volume and the number of cells per unit volume.The results show a definite interstitial‐cell cycle. Volume of interstitial tissue and size of individual cells are greatest during the breeding season, but the interstitial‐cell number is then minimal. The maximal number of interstitial cells occurs after the close of the breeding season. There is, apparently, no reversion of interstitial cells to a connective‐tissue‐cell type.The above changes are correlated with the spermatogenetic cycle and with increases in total tubule length, in tubule diameter, and in testis volume. The time in which important changes in ovarian volume occur and at which ovulation takes place is coincident with the testicular changes.Interstitial cells have been stated to have no endocrine function for the reason that their number is at a minimum during the breeding season. If, however, interstitial tissue is responsible for sex characters and activity, the present work would indicate that it is the volume of tissue, and not the number of cells, that is important.