University of Khartoum

Morpholgical Development and Biochemical Changes in THE Reproductive Tract oF The Nubianb Bucks with Special Reference of Puberty

Morpholgical Development and Biochemical Changes in THE Reproductive Tract oF The Nubianb Bucks with Special Reference of Puberty

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Title: Morpholgical Development and Biochemical Changes in THE Reproductive Tract oF The Nubianb Bucks with Special Reference of Puberty
Author: ABDEL RAHMAN, SARA
Abstract: This study was designed to monitor the morphological and biochemical development of the reproductive tract of the Nubian bucks in relation to puberty. Thirty two (32) Nubain male kidswere allotted to this study. Their ages ranged between 1 day and 24 weeks old, and body weights of 2.3-13.5 kg. Data collected from these animals included, body weight (BW), heart girth (HG), scrotal circumference (SC) and penile separation from prepuce (PS). Blood samples were collected from the jugular vein twice from each animal, before hCG injection and 1 hour after hCG treatment for determination of testosterone, LH, FSHand prolactin (PRL) level in the peripheral circulation. These animals were slaughtered at intervals of two weeks starting from one day old up to 24 weeks of age. Tissue samples were taken from the testis, epididymis, ductus deferens and root of the penis and processed for histological and ultrastructural studies. The boundary tissue of the newly forming seminiferous tubule adhered closely to the basal laminae. It consisted of onecontinuous layer of myoid cells, the outer surface ofwhich was covered by scattered fibroblasts; many collagenous fibersintermingled with the cellular components. An ultrastructural study ofthe boundary tissue of the seminiferous tubule of the Nubian bucks revealed that it consisted of three layers: inner fibrous, middle and outer cellular. xiii A gradual increase in the diameter of the tubules and epithelial height continued with increase of age.The seminiferous tubules at week one were lined by two layers of epithelia; spermatogonia and Sertoli cells in the basal layer, and primary spermatocytes in the second layer. Spermatocytes number has shown an increase with age. Based on the appearance of spermatozoa in the lumina of the seminiferous tubules, and penile separation and attainment of maximal hormonal (testosterone, LH, FSH and PRL) levels, puberty age was reached between weeks 18-20. The Sertoli cells were rounded or oval in shape with small amounts of cytoplasm. The nuclei were irregularly round in shape and occupied most of the cytoplasm. Clusters of Leydig cells were seen in the intertubular tissue. The nucleus was oval or rounded occupied most of the cytoplasm and showed a dense heterochromatin layer on the inner nuclear surface. Morphologically, three cell types were identified in the epididymis: principal, apical and basal cells. The lining epithelium of the head and both segments of the tail consisted ofhigh columnar principal cells and basal pyramidal cells. The principal columnar cells were the main component of the epithelial lining. They had elongate nuclei which were occasionally lobulated and occupiedthe middle parts of cells. The pyramidal cells were densely stained and had irregular nuclei. Interdigitations of apposed plasmamembranes and extensive tight junctions were noted. Abundant mitochondria, well developed Golgi Complex, profiles of RER and electron lucent material were seen. The tubules of the body of the epididymis were surrounded by smooth muscle fibers which amounted to about 10 layers in thickness. xiv The tubular diameter was 211 µm and it increased with age. They were lined by simple columnar epithelium. Their lateral plasma membranes were straight and held together by desmosomes, macula adherens, while the luminal border was equipped witha few microvilli. The nucleus was elongate. The cytoplasm was rich in organelles. The tubular diameter of the ductus deferens was 3161 µm and the epithelial height was 56-103 µm. Both ofthem increased with age. It was constituted of four layers; mucosa, sub- mucosa, muscular layer and adventitia. The ductus deferens was lined with pseudostratfied columnar epithelium. The tall cells extended from the base to lumen whereas the basal cells rested on the basal lamina. The tall cells possessed elongate nuclei which occupied the middle parts of the cells. The basal cells were small, dense and irregular in shape. The diameter of the penis was 6988 µm wide. The skin was closely adherent to the underlying tissue in which Meissner's corpuscles were seen. An inner folded band encircled the corpus spongiosum penis and corpus cavernosum penis and consisted of about ten layers, mainly cuboidal cells in the center, covered on either sideby columnar cells and overlying layer of connective tissue containing a band of smooth muscle fibers and collagen fibers. Penile separation started slightly at 12 weeks of age and continued with advancing age till it was completely achieved between 22 and 24 weeks of age. After hCG injection, the plasmalevel of testosterone was significantly higher (p< 0.01) than the level of the hormone before hCG treatment. Significant increase was also observed in LH values after hCG injection (P<0.01). xv Plasma FSH showed one peak at 8 weeks of age in the sample taken before hCG injection. This was followed in 2 weeks time by the first elevation of LH. Plasma PRL concentration showeda gradual increase with age reaching the peak at 18 weeks. The study was undertaken to correlate the body weight (Bw), scrotal circumference (SC), Heart Girth Circumference (HG), testicular descent into scrotum and penile separation from prepuce to the sexual maturity. A positive correlation was evident and it was especially so between the onset of spermatogenesis and penileseparation. A good correlation has been established between the levels of the reproductive hormones and the morphological maturation of the reproductive tract. The first surge in the levels of these hormones (occurred between weeks 10 and 12) coincided with the increase in the diameters of the seminiferous tubules, the epididymis, ductus deferens and the penis. The first appearance of secondary spermatocytes and initiation of penile separation occurred during this period. The second surge was associated with the first appearance of spermatids, spermatozoa and completion of penile separation, which occurred between weeks 20 and 24.
Description: 198page
URI: http://khartoumspace.uofk.edu/handle/123456789/9001
Date: 2015-04-15


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