• The Korean Journal of Zoology
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• v.33 no.4
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• pp.435-445
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• 1990

Gonadotropin releasing horrnone (GnRH) is known to be extrahypothalamically localized with a broad range including gonad. It remains, however, unknown whether GnRH is locally synthesized in the gonad. The present srudy aims to identity expression and cellular localization of GnRH-Iike mRNA and immunoreactive GnRH in the rat gonad. GnRH radioimmunoassay and chromatographic extracts on G-50 sephadex column showed that rat gonadal extracts contained a substantial amount of immunoreactive GnRH similar to the hypothalamic and synthetic GnRH. Although a wide distribution of immunostainable GnRH-like molecule with different cell types in the rat ovary was observed, the major cell population hybridized with GnRH probe appears to be granulosa. theca cells and corpus luteum. Immunoreactive GnRH-Iike peptides were distributed m various regions of testis, including spermatogenic cells, Sertoli cells and Leydig cells. In situ hybridization revealed that positive signals of GnRH-Iike mRNA were predominandy present in Sertoli cells within some seminiferous tubules, but absent in the outside of seminiferous tubules in the testis. This study clearly demonstrated that GnRH-Iike molecule present in the rat gonad may be resulted from the local synthetic machinery of GnRH supporting the notion that this peptide may act as autocrine and/or paracrine role in intra-gonadal communication.

• Applied Microscopy
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• v.38 no.3
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• pp.205-212
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• 2008

In this study morphological changes of the testes of golden hamsters treated with 6-aminonicotinamide (6-AN, 10 mg/kg body weight) in every two days were investigated using light and transmission electron microscopes. After the 7th injection of 6-AN, body weights of hamsters were significantly reduced, and the weight of testes were markedly reduced in the group of hamsters after 5th injections. Degeneration of seminiferous epithelium appeared first in the group receiving 5th injections, which were followed by severe degenerations after the 9th injection. In the degenerated seminiferous epithelium, deep vacuolization, and destruction of spermatogenic cells and Sertoli cells were also oberved. Multinuclear giant cells were also observed in the lumen of destructed seminiferous epithelium. But there were no edematous changes in the interstitial tissue, and the Leydig cells were found to be relatively intact. Therefore, these results show that 6-AN trigger severe morphological alteration of the spermatogenic cells and Sertoli cells, however Leydig cells are unaltered by 6-AN.

• Applied Microscopy
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• v.33 no.1
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• pp.25-39
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• 2003

Cell differentiation and ultrastructural characteristics in the seminiferous epithelium of Myotis macrodactylus was investigated with the light and electron microscopes. Spermatogenesis has begun at April and finished at September. The nuclei of A spermatogonia (dark and pale type of spermatogonia) were oval, applied to the basal lamina, and surrounded by Sertoli cells. By comparison with other types of spermatogonia, the cell and nucleus of B type of spermatogonium is globular and larger than A types of spermatogonia. The nucleolus appears as a coarse and touches the nuclear membrane. The cell and nucleus of spermatocytes was globular and larger, but primary spematocyte is larger than secondary spermatocyte. Spermiogenesis was divided according to the level of fine structural difference, into Golgi, cap, acrosomal, maturation and spermiation phases; Golgi, cap, acrosomal and spermiation phases were further subdivided into steps of early and late phase respectively, and maturation phase has only one step. Hence, the spermiogenesis has been divided into a total of nine phases. In the change of karyoplasm, the chromatin granules are condensed at late Golgi phase and completed at spermiation phase. The sperm tail began to develop in early Golgi phase and completed in spermiation phase. The process of degeneration of spermatogenic cells in the seminiferous tubules was continually observed from October, before the beginning of hibernation, to hibernation phase (November, December, January, February, March). Immatured spermatogenic cells in the seminiferous tubules have been engulfed by phagocytosis of Sertoli cells during period of degeneration. It is deduced that the adaptative strategy serves as the mechanism to regulate the effective use of energy to prepare for long hibernation and regulation of breeding cycle.

• Journal of Life Science
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• v.15 no.3 s.70
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• pp.387-396
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• 2005

The aims of the study were to establish a short-term screening test for detecting testicular toxicity of chemicals in rats and to determine whether a 2-week administration period is sufficient to detect testicular toxicity of 2-bromopropane (2-BP) as an example. Male Sprague-Dawley rats were subcutaneously administered with 1000 mg/kg/day of 2-BP or its vehicle for 2 weeks. Ten male rats each were sacrificed on days 3, 7 and 14 after the initiation of treatment. Parameters of testicular toxicity included genital organ weights, testicular sperm head counts, epididymal sperm counts, motility and morphology, and qualitative and quantitative histopathologic examinations. The early histopathological changes observed on day 3 of treatment included degeneration of spermatogonia and spermatocytes, multinuclear giant cells, mature spermatid retention, vacuolization of Sertoli cells, and decreased number of spermatogonia in stages II and V. On day 7 of treatment, atrophy of seminiferous tubules, exfoliation of germ cells, degeneration of spermatogonia and spermatocytes, multinuclear giant cells, mature spermatid retention, vacuolization of Sertoli cells, decreased number of spermatogonia in stages II and V, and decreased number of spermatocytes in stages VII and XII. On day 14 after treatment, a significant decrease in the weights of testes and seminal vesicles was found. Atrophy of seminiferous tubules, exfoliation of germ cells, degeneration of spermatogonia and spermatocytes, mature spermatid retention, vacuolization of Sertoli cells, decreased number of spermatogonia in stages II and V, and decreased number of spermatocytes in all spermatogenic stages were also observed. In addition, a slight non-significant decrease in testicular sperm head counts, daily sperm production rate and epididymal sperm counts was found. The results showed that 2 weeks of treatment is sufficient to detect the adverse effects of 2-BP on male reproductive organs. It is considered that the short-term testicular toxicity study established in this study can be a useful tool for screening the testicular toxic potential of new drug candidates in rats.

• Korean Journal of Animal Reproduction
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• v.10 no.1
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• pp.100-108
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• 1986

Eik-Nes (1966) reported that the mechanism of spermatogenesis is controlled by FSH and LH and maintaned normally in scrotum terperautre which is 3-5$^{\circ}C$ lower than body termperature. But Ojeda and Ramirez (1972) have described that the abdominal testis was shrinked severely and lost its normal function in congenital cryptorchidism or surgically induced cryptorchidism. Ramirez and Sawyer (1974) reported that the compensatory hypertorphy occured in the remaining testis of unilateral castration and the scrotal testis of unilateral cryptorchidism. Cunninham et al. (1978) reported that the serum FSH levle increased after unilateral castration. Frankel and Wright (1982) reported that the serum LH level was unchanged greatly after unilateral castration. Gomes and Jain (1976) reported that the serum testosterone level increased temporarily but not varied after unilateral castration. On the other hand, Kormano et al. (1964) reported that the serum FSH level in unilateral cryptorchidism rat was unchanged in contrast with the control and Risbirdger et al. (1981) reported that the serum LH level was unchanged till 2 weeks after operation and after then increased to 77%. Kim (1984) reported that the serum testosterone level was somewhat lower than that fo control group but there was't significant different. There were many different reports on hormone levels among different investigators when the immarue rats were castrated unilaterally or induced cryptorchidism unilaterally. Liang and Liang (1970) and Cunningham et al. (1978) described that there were no true compenastory hypertrophy in the remaining testis of unilateral castration and scrotal testis of unilateral testis of unilateral cryptorchidism in rat but they grew faster than that of control. Kormano et al.(1964), Damber et al.(1976), Cunningham et al.(1978) and Karpe et al.(1981) reported that the testis weight, germinal epithelia height and seminiferous tubules diameter developed continuously and similarily in the control, the remaining testis of unilateral castration and scrotal testis of unilateral cryptorchidism increased, however, in the abdominal testis of the unilateral cryptorchidism, they were much smaller than those of other groups. In observation of the histological changes in the seminiferous epithelium of control, remaining tesis of unilateral castration and scrotal testis of unilateral cryptorchidism differentiated and developed fully(Cunningham et al., 1978). However, the abdominal testis of unilateral crytorchidism degenerated severely and only the germ cells in early stage and Sertoli cells were found in the seminiferous tubules. (Damber et al., 1976, Gomes and Jain, 1976 and Karpe et al., 1981). By electron microscopic observation, Nagano (1963) and Leason and Leeson (1970) found that the abdominal testis of unilateral cryptorchidism was thicked in boundary tissue, increased lipid droplet in the Sertoli cell, disarranged axial filament complex and increased lipid inclusions in the Sertoli cell.

• Clinical and Experimental Reproductive Medicine
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• v.26 no.1
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• pp.103-109
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• 1999

Objective: Heat shock protein 70-2 (Hsp70-2) gene knockout mice are found to have premeiotic arrest at the primary spermatocyte stage with a complete absence of spermatids and spermatozoa. This observation led to the hypothesis that hspA2 may be disrupted in human testes with abnormal spermatogenesis. To test this hypothesis, we studied the mRNA expression of hspA2 in infertile men with azoospermia. Design: The mRNA expression were analyzed by competitive RT-PCR among testes with normal spermatogenesis, pachytene spermatocyte arrest, and sertoli-cell only syndrome. Materials and methods: Testicular biopsy was performed in men with azoospermia (n=15). Specimens were subdivided into three groups: (group 1) normal spermatogenesis (n=5), (group 2) spermatocyte arrest (n=5), (group 3) Sertoli-cell only syndrome (n=5). Total RNA was extracted by Trizol reagent. Total extracted RNA was reverse transcribed into cDNA and amplified by PCR using specific primers for hspA2 target cDNAs. A competitive cDNA fragment was constructed by deleting a defined fragment from the target cDNA sequence, and then coamplified with the target cDNA for competitive PCR. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene was used as an internal control. Results: On Competitive RT-PCR analyses for hspA2 mRNA, significant amount of hspA2 expression was observed in group 1, whereas a constitutively low level of hspA2 was expressed in groups 2 and 3. Conclusion(s): The study demonstrates that the hspA2 gene expression is down-regulated in human testes with abnormal spermatogenesis, which in turn suggests that hspA2 gene may play a specific role during meiosis in human testes.

• Toxicological Research
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• v.7 no.1
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• pp.83-92
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• 1991

Complexities of testis structure and function are emphasized in morphometrical and genotoxic evaluation by statistical analysis. F-344 rats were treated with azinphos methyl, cyclophosphomide, and dichlorvos. And Brdu was injected with intrapertionially before sacrifice. The existence and degree of DNA damage were measured by Brdu labeling index which represented relative amount of Brdu incorporated in DNA, morphometric change was evaluated by the relative length of tubular diameter in circular seminiferous tubules and the number of spermatogonia per Sertoli cell in stage IX seminiferous tubules.

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2005.11a
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• pp.76-76
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• 2005

• Korean Journal of Poultry Science
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• v.24 no.3
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• pp.107-116
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• 1997

In order to achieve optimal reproductive performance, reliable morphological and physiological basic data on the reproductive organs are desirable. Adult male Korean ring-necked pheasant in inactive(mid of January) and active state (end of April) were used in this study. In addition, five active state pheasants were received a single dose of 60Co-ray 500 rads each to damage the testes. The objective of this study was to investigate the distribution pattern of protein gene product (PGP) 9.5 and ${\alpha}$-tubulin in the pheasant testes of the active, inactive and ${\gamma}$-ray irradiated active states. The results obtained were summarized as follows 1. The seminiferous tubules collected in inactive states( mid of Jan) showed narrow lumen, and the spermatogonia and the Sertoli cell were well preserved. The PGP 9.5 immunoreactivity of these tubules showed a positive reaction in paranucleus area of the spermatogonia, and a positive reaction in a small number of the Leydig cells in the interstitium of the seminiferous tubules. 2. The seminiferous tubules were dilated in active state(end of April) as compared with the inactive state. The PGP 9.5 reactivity in these tubules showed a positive reaction in many Leydig cells in the interstitium of the seminiferous tubules, and the testes of ${\gamma}$-ray irradiated group showed partially weak reaction in the interstitium of the seminiferous tubules. 3. The ${\alpha}$-tubulin reactivity in the seminiferous tubules of the inactive testes was strongly positive in the cytoplasmic process of the Sertoli cell from the basal stem region to the apical ex-tension. From the broad part of the stem region to the luminal space, the active testes showed a strong positive reaction. The ${\gamma}$-ray irradiated groups showed diminished reaction in the basal region.

• Clinical and Experimental Reproductive Medicine
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• v.31 no.4
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• pp.235-244
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• 2004

Objective: The effects on spermatogenesis by expression of vascular endothelial growth factor (VEGF) and endothelin-1 (ET-1) were investigated. Materials and Methods: Testicular specimens were obtained from 40 infertile males due to primary testicular failure and from 10 fertile males with other urologic problems. The specimens of infertile males were devided into 4 groups according to histologic findings; Sertoli cell only syndrome (A), maturation arrest (B), hypospermatogenesis (C) and sloughing and disorganization (D). VEGF and ET-1 expression were detected with immunohistochemical stain. Results: VEGF expression on Leydig cell was detected in all cases. But, VEGF expression rates on germ cell were significantly higher in infertile group B, C, D compared to that of the control group (p<0.05). ET-1 expression rates on Leydig cell was significantly lower in all infertile group compared to that of the control group (p<0.05). But, ET-1 expression rates on Sertoli cell was significantly higher in all infertile group compared to that of the control group (p>0.05). In germ cell of infertile group, LH, FSH and prolactin were significantly decreased, and estradiol is increased in positive stain group on ET-1 immunohistochemical stain (p<0.05). VEGF and ET-1 expression were not correlated mean seminiferous tubule diameter (p>0.05). Conclusions: Abnormal spermatogenesis would be reflected in VEGF expression in germ cell.