A Histological, Histochemicaland Morphometric Study On the Postnatal Development of the Intratesticular Tubular System of Nubian Goat Kids

No Thumbnail Available
Abakar, Fatima
Journal Title
Journal ISSN
Volume Title
1. A histological, histochemical and morphometric study has been conducted on the intratesticular tubules in 35 nobian kids of different age. The age varied from 5 to 21 weeks and onward (sexually mature kids). 2. The intratesticular tubules are classified into seminiferous cords and seminiferous tubules and their excurrent ducts. 3. The intratesticular excurrent ducts consisted of the terminal segments of the seminiferous tubules, the tubuli recti and the rete testis. 4. The seminiferous tubules occupy the lobules forming the testicular parenchyma. 5. The intratesticular excurrent ducts are localized within and around the central axial mediastinum testis. 6. Age is a major factor in the increase of the diameter of the developing seminiferous tubules and their excurrent ducts. 7. The developing seminiferous tubules lack lumina and are lined by one layer of spermatogonia and Sertoli cells. They are known as the seminiferous cords during 5 to 10 weeks of age. 103 8. One to three large gonocytes are found toward the centre of the seminiferous cords at 5-6 weeks ofage and disappeared at 12-15 weeks of age. 9. The primary spermatocytes are present within the seminiferous cords at 8-10 weeks of age. 10. The seminiferous cords were transformed into seminiferous tubules by acquiring a lumen at 12-15 weeks of age. 11. Round and elongated spermatids are present at 17-18 weeks of age. 12. Spermatozoa appear at 21 weeks of age and onward. 13. The terminal segments are differentiated at 12-15 weeks and are lined with modified Sertoli cells. 14. The terminal segments of the seminiferous tubules acquire lumina at 17-18 weeks of age. 15. The terminal segment of the seminiferous tubules is subdivided into: transitional region, middle region and terminal plug according to the depletion of the germinalepithelium and its replacement by the modified Sertoli cells at21 weeks of age and onward. 16. The tubuli recti appear as small tubules between 5 and 10 weeks of age, and are modified into: proximal dilated parts, the receptacles and main narrow parts at12-15 weeks of age. 17. The receptacles are lined with squamous or cuboidal cells and the main parts are lined with cuboidal cells. 104 18. The rete testis consists of a group of channels which occupy an axial mediastinum testis, and becomes cavernous and intercommunicated at 21 weeks of age and onward. 19. A few intraepithelial lymphocytesare present in the terminal segments and mains parts of the tubuli recti. 20. PAS-positive diastase resistant material is detected in the boundary tissue of all segments of the intratesticular tubules, specially in the terminal segments and rete testis. 21. Glycogen particles show cyclic changes in the lining epithelium of the developing seminiferous tubules and their number decrease with advancing age. 22. The epithelium of the intratesticular tubules show positive reaction for acid phosphatase enzyme and the reaction is detected in the lining epithelium and the reaction increased with advancing age. 23. Strong activity for alkaline phosphatase is demonstrated in the basement membrane and the cytoplasm of the epithelium lining of the intratesticular tubules. The reaction in the lining epithelium decreases with advancing age. 24. The terminal segments show positive reaction for alkaline phosphatase in both the basementmembrane and the lining epithelium and the reaction is stronger than that of the seminiferous tubules. 105 25. The morphometry of the intratesticular tubules has been studied in nine kids (three kids from each age group refrred to as group A, group B and group C). 26. The mean absolute volume of the testis of group (A) is about 2.333cm³ ± 0.577, and increased in group (B) to 21cm³ ±11.53 and further increased in sexually maturekids (group C) to 61.66cm³ ±10.41. 27. The seminiferous cords gave meanvalue about 38.60% (0.895cm³ ±0.187) in group (A) and transformed into seminiferous tubules in group (B) and group (C) which constituted the largest components of the testicular volume (55.40% 11.21cm³ ±5.303) in group B and (70.93% 43.70cm³ ±7.809) in group C. 28. The interstitial connective tissue constituted the largest components of the testicular volume in group (A) 46.30% (1.092cm³ ±0.364) and decreased in group (B) to32.19% (6.390cm³ ±2.280) and further decreased in group (C) to 21.66% (13.32cm³ ±3.329). 29. The terminal segments of the seminiferous tubules were not developed in group (A) and occupy a very small portion in group (B) 0.046% (0.010cm³ ±0.007) and group (C) 0.137% (0.077cm³ ±0.055). 30. The tubuli recti represent a meanvalue of 0.067% (0.002cm³ ±0.001) in group (A) and increased slightly in group (B) to 0.129% 106 (0.027cm³ ±0.020) and further increased in group (C) to 0.200% (0.120cm³ ±0.018). 31. The mediastinal connective tissue represents a mean value of 11.89% (0.270cm³ ±0.063) in group (A) and decreased to 7.900% (2.125cm³ ±2.320) in group (B) and further decreased to 4.753% (2.942cm³ ±1.288) in group (C). 32. The percentage of the rete testis volume was 3.138% (0.074cm³ ±0.024) in group (A) and slightly increased in group (B) to 4.324% (1.238cm³ ±1.685) and then decreased in group (C) to 2.297% (1.488cm³ ±0.823)
Histological, Histochemical, Morphometric Stud