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Radiation Damage of the Reproductive Organs
Published in Kedar N. Prasad, Handbook of RADIOBIOLOGY, 2020
The processes of the formation of sperm are referred to as spermatogenesis. The highly proliferating spermatogonia line the seminiferous tubules and give rise to primary and secondary spermatocytes, which then form spermatids. The spermatids do not divide. Each spermatid matures into one spermatozoon. On the criterion of cell death, spermatogonia are most radiosensitive, whereas spermatids and spermatozoa are most radioresistant, but the possibility of genetic damage is high for all cellular elements. The interstitial cells that produce male hormone are also highly radioresistant. Therefore, men exposed at a sterilizing dose (500–600 rads) of radiation retain their fertility and produce seminal and prostatic fluid without sperm for a while. After irradiation, the testis becomes smaller and softer, and may become sterile. However, no change in the beard, voice, or social behavior has been observed.
Mammalian Spermatozoa
Published in Claude Gagnon, Controls of Sperm Motility, 2020
The axoneme of spermatids, the growth of which is triggered by one of the two centrioles (i.e., the distal one), elongates as in any growing cilia by the addition of tubulins at the distal ends of the microtubular singlets and doublets.157 This process appears to take place during the early steps of spermiogenesis (i.e., steps 1 to 3). Indeed, the distal extremities of the axonemes of step 3 spermatids are seen in the center of the lumen of the seminiferous tubules and thus at a considerable distance from the intracytoplasmic centrioles.158 It should be remembered that the axoneme of spermatids is remarkably long (190 μm in the rat). This feature presupposes that the synthetic machinery (rRNA, mRNA) for the production of tubulins and associated proteins has to be in place and be fully functional at the very onset of spermiogenesis.
The Pathophysiology of Male Infertility
Published in Botros Rizk, Ashok Agarwal, Edmund S. Sabanegh, Male Infertility in Reproductive Medicine, 2019
Spermatogenesis disorders may be evaluated by testicular biopsy, and oftentimes, spermatozoa are procured for ART. In this regard, the pathological observations mostly reveal either “mixed atrophy” (tubules having different spermatogenic phases), several forms of developmental or morphological defects in spermatozoa (e.g., round spermatid or meiotic arrest), or even “Sertoli cell-only syndrome” (SCOS, where absolute absence of germ cells can be observed). These characteristics of spermatogenesis disorders can be global, which involve all the seminiferous tubules or focal with a number of tubules suffering from quantitative or qualitative spermatogenesis defects [2]. The pathophysiology of spermatogenic impairment from a molecular perspective is still arduous. This is due to lack of detailed functional concepts on the testes, which do not simply comprise the two established compartments: The interstitial part (containing the most prominent testosterone-producing Leydig cells, among other underdiscussed components) and seminiferous tubules (with the germ cells and supporting Sertoli cells). Moreover, spermatogenesis itself is an intricate differentiation process, completely transforming spermatogonia to mature spermatozoa via various stages. Such continuous coordinated processes are being mediated via integration of neuroendocrine and genetic dispositions, amid other physiological regulations and is reportedly orchestrated by almost 2,000 genes, of which more than 600 are supposedly expressed in the male germline [3,4,24,25].
Evaluating the histomorphological and biochemical changes induced by Tributyltin Chloride on pituitary-testicular axis of adult albino rats and the possible ameliorative role of hesperidin
Published in Ultrastructural Pathology, 2023
Sahar F. Shaban, Maha A. Khattab, Samar H. Abd El Hameed, Shaimaa A. Abdelrahman
Sections stained with H&E of the testes in the control group showed that the testicular parenchyma was formed of contiguous seminiferous tubules separated by the interstitium. The seminiferous tubules were surrounded by thin regular basal lamina and lined with stratified germinal epithelium and Sertoli cells. The germinal epithelium was composed of spermatogonia, primary spermatocytes, early and late spermatids. Sertoli cells had large, pale nuclei resting on the basal lamina. Interstitial cells of Leydig appeared between the seminiferous tubules, they were round in shape with vesicular nuclei (Figure 8a). TBT-treated group showed thickened connective tissue capsule with congested blood vessels. The seminiferous tubules appeared markedly distorted with irregular basal lamina and showed marked cell loss indicated by wide separation between germinal epithelial cells. Most cells had darkly stained nuclei (Figures. 8b, c). The Hesperidin-TBT treated group showed nearly normal appearance of the seminiferous tubules with thin regular basal lamina. The germinal epithelium was composed of spermatogonia, primary spermatocytes, early and late spermatids. Sertoli cells appeared with pale nuclei. Interstitial cells of Leydig had rounded vesicular nuclei (Figure 8d). In the recovery group, the seminiferous tubules still showed less cellularity with separation between the germinal epithelial cells which have dark nuclei. The interstitial tissue showed homogenous acidophilic materials and vacuolation (Figure 8e).
Acrylonitrile’s genotoxicity profile: mutagenicity in search of an underlying molecular mechanism
Published in Critical Reviews in Toxicology, 2023
Richard J. Albertini, Christopher R. Kirman, Dale E. Strother
ACN’s potential for inducing numerical chromosome aberrations, i.e. aneuploidy, is suggested by a single Drosophila study of sex-linked chromosomes. The human study with its several deficiencies also claims to have found sex-linked aneuploidy in ACN-exposed workers. Also, the cytogenetic study that reported an increase in chromosome aberrations in ACN-exposed mice included a class of meiotic changes that theoretically could result in aneuploidy, although no numerical chromosome changes were observed. These findings in the existing data base could all be addressed in a repeat cytogenetic study. Cytogenetic analyses of male germ cells, i.e. spermatogonia, spermatocytes and early spermatids, is a well-established method for detecting both structural and numerical chromosome aberrations in rodents (Allen et al. 1986; Adler et al. 2012; Yauk et al. 2015; OECD Guideline 483, 2016). Chromosome painting can add to the precision of the analysis. Micronuclei may also be measured in spermatids (Adler et al. 2012). An add-on to the proposed cytogenetic studies that may at least suggest transmission of numerical chromosome aberrations would be FISH analysis of mature sperm using sex-chromosome centromere probes.
The ameliorative effect of Lactobacillus paracasei BEJ01 against FB1 induced spermatogenesis disturbance, testicular oxidative stress and histopathological damage
Published in Toxicology Mechanisms and Methods, 2023
Khawla Ezdini, Jalila Ben Salah-Abbès, Hela Belgacem, Bolanle Ojokoh, Kamel Chaieb, Samir Abbès
The daily sperm production (DSP) was assessed following the research protocol of Kyjovska et al. (2013) with some modifications. Indeed, the right testis was harvested after the sacrifice. Its half was homogenized for 60 s in a saline solution containing 0.9% NaCl and 0.05% Triton X-100. Only spermatids of the 14th and 16th stages were resistant to homogenization. To visualize them, staining with the Trypan blue 0.04% in PBS (1 M) was done for 30 min before counting. The spermatids were counted with a light microscope at ×400 magnification. The total elongated spermatids in the right testis were calculated by multiplication with the right testis weight. DSP was calculated by dividing the total of spermatids counted by 4.84 days that spermatids spent to develop into stages 14–16 in mouse species (Oakberg 1956). Then, DSP was divided by the weight of the testis to determine the number of sperm per gram of testis, which corresponds to the efficiency of sperm production.