STUDIES OF THE DEFERENT DUCTS FROM THE TESTIS OF THE AFRICAN ELEPHANT, LOXODONTA-AFRICANA .2. HISTOCHEMISTRY OF THE EPIDIDYMIS

  • 1 January 1980
    • journal article
    • research article
    • Vol. 130  (MAR) , 367-379
Abstract
The epididymis of the elephant is of special interest because it is considered to be primitive; structural studies indicate that it is differentiated along its length, and it may be structurally and functionally classified into 3 main regions. The differentiation of the epididymis was examined using cytochemical methods. Hydrolases [acid and alkaline phosphatase, non-specifice esterase and ATPase], oxido-reductases [succinate dehydrogenase (SDH), G-6-P dehydrogenase (G-6-PD), hydroxysteroid dehydrogenases and diaphorases], lipids, carbohydrates and glycoproteins were localized in the spermatozoa and epididymal epithelium using conventional histochemical methods. A layer of neuraminidase-resistant, acidic glycoprotein lined the luminal surface of the epithelium throughout the duct, being particularly evident in the terminal segment. Intraepithelial neutral lipids were detected in the middle and terminal segments, but the strongest reaction for phospholipids occurred in the initial segment. All the enzymes except the steroid dehydrogenases were detected in the epididymal epithelium. Those probably involved in active transport, i.e., ATPase and alkaline phosphatase, showed strongest reactions in the initial and terminal segments, with intense activity in the stereocilia. The enzymes involved in energy metabolism, i.e., SDH, G-6-PD and diaphorases showed strongest reactions in the middle and terminal segments. The lysosomal enzymes, non-specific esterase and acid phosphatase showed differing localizations, the former being most active in the middle and terminal segments while the latter occurred predominantly in the initial and middle segments. The initial segment is evidently involved in absorptive and anabolic activity, the middle segment in anabolic activity, and the terminal segment in considerable metabolic activity and active transport.