Recent studies have demonstrated that cholesterol and testosterone may be synthesized in vitro from acetate by mouse and rat epididymides (Hamilton, Jones & Fawcett, 1969; Hamilton & Fawcett, 1970). McGadey, Baillie & Ferguson (1966) were the first to demonstrate histochemically some of the steroid-metabolizing enzymes in the hamster epididymis, and subsequently a number of workers (Gloyna & Wilson, 1969; Inano, Machino & Tamaoki, 1969) have verified by biochemical means the existence of steroid-converting enzymes in the epididymal tissue of a number of mammals. McGadey et al. (1966), however, did not find 3β-hydroxysteroid dehydrogenase in the hamster epididymis. This enzyme is very much concerned with steroid biosynthesis, converting pregnenolone and dehydroepiandrosterone (DHA) to progesterone and androstenedione, respectively (Baillie, Ferguson & Hart, 1966). In many vertebrates, steroid-producing organs
K. A. MONIEM and T. D. GLOVER
Alkaline phosphatase activity has been examined in ram, rabbit, hamster and rat spermatozoa. Results have shown that the enzyme is restricted to the cytoplasmic droplet in rabbit and ram spermatozoa but that the intensity of reaction is highest in rabbit spermatozoa. The enzyme could not be demonstrated at all in the spermatozoa of the hamster or rat.
It has also been shown that alkaline phosphatase activity in the droplet of rabbit spermatozoa decreases during epididymal transit and that there is a reduction in activity in degenerating spermatozoa. Degeneration in spermatozoa was produced in rabbits by means of artificial cryptorchidism, and after 2 weeks, activity in the droplets was completely lost.
M. D. Tingari and K. A. Moniem
Summary. Distinct morphological regions, initial, middle and terminal segments, were distinguishable histologically; the middle segment was further subdivided into proximal, intermediate and distal parts.
PAS-positive, diastase-resistant reaction was detected in the blood vessels, subepithelial tissue and stereocilia of all segments. Acid phosphatase was demonstrated in the epithelial cells with the highest activity being in the proximal part of the middle segment. Non-specific esterase gave a similar reaction but the strongest activity was in the terminal segment. Alkaline phosphatase, adenosine triphosphatase and adenosine monophosphatase were of similar activity in the subepithelial tissue, blood vessels, stereocilia and luminal contents; the strongest reaction occurred in the middle segment. Lactate, succinate, glutamate and glucose-6-phosphate dehydrogenases were examined; LDH was more active than the others particularly in the terminal segment. Some reaction was found in the epithelial cells, subepithelial tissue and luminal contents.
K. A. Moniem, T. D. Glover and C. W. Lubicz-Nawrocki
Summary. The epididymis was ligated at the efferent ductules and at the middle segment. Histochemical changes occurred only proximal to the ligature. Orchidectomy caused progressive changes, mostly reversible by testosterone treatment, throughout the epididymis. It is concluded that the integrity of the initial segment is dependent upon androgen reaching it via the testicular fluid.