• Development and Reproduction
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• v.10 no.3
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• pp.203-209
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• 2006

Ethane 1,2-Dimethane sulfonate(EDS), a toxin which specifically kills Leydig cells(LC), has been widely used to prepare the reversible testosterone(T) depletion rat model. Previous studies including our own clearly demonstrated that the dramatic weight loss of the T-dependent accessory sex organs such as epididymis and seminal vesicle in this 'LC knock-out' rats. These weight loss could be derived from massive and abrupt death of the cells via apoptotic process. The present study was performed to test the effect of EDS administration on the expression of some apoptotic genes in the rat epididymis. Adult male Sprague-Dawley rats($300{\sim}350$ g B.W.) were injected with single dose of EDS(75 mg/kg, i.p.) and sacrificed on Weeks 0, 1, 2, 3, 4, 5, 6 and 7. Tissue weights and the numbers of the epididymal sperm were measured. The transcriptional activities of the bcl-2, bax, Fas and Fas ligand(Fas-L) were evaluated by semi-quantitative RT-PCR. As expected, the weights and the sperm counts of epididymis declined progressively after the EDS treatment during Week 1 and 2. These decrements were discontinued with a gradual return towards normal during Weeks $5{\sim}7$, although the maximal recoveries of the epididymal weights(71%) and sperm count(38%) were subnormal on Week 7. The initial level of bcl-2 transcripts persisted to Week 6 then elevated significantly on Week 7. The level of bax transcripts significantly decreased on Week 6, and no remarkable change was found in the rest of the experimental period. The transcripts for the Fas in epididymis elevated during Weeks $1{\sim}2$, returned to normal on Week 3, and the level persisted to the Week 7. Similarly, the level of Fas-L transcripts elevated during Weeks $1{\sim}3$ and returned to normal after Week 4. Our results demonstrated the transient T depletion by EDS administration could induce the changes in expression of the apoptotic genes in rat epididymis. The activation of Fas and Fas-L in the epididymis of EDS-treated rats might be responsible for the initial apototic process and consequently the tissue damage and the sperm loss. Future studies will attempt to determine the precise molecular mechanism(s) of apoptosis in the rat epididymis.

• Development and Reproduction
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• v.13 no.2
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• pp.105-114
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• 2009

Ethane 1,2-dimethane sulfonate (EDS) is a well-known alkylating agent used as selective Leydig cell (LC) toxicant to create a testicular dysfunction model. Previous studies including our own clearly demonstrated the dramatic weight loss of the androgen dependent accessory sex organs such as epididymis, seminal vesicle and prostate gland in this 'LC knock-out' rats. The present study was performed to evaluate the effect of EDS administration on histological changes of the epididymis, seminal vesicle and prostate in adult rats. Adult male Sprague-Dawley rats (350$\sim$400 g B.W.) were injected with a single dose of EDS (75 mg/kg, i.p.) and sacrificed on weeks 0, 1, 2, 3, 4, 5, 6 and 7. Tissue weights (testis, epididymis, seminal vesicle and prostate gland) were measured. The histological changes of tissue were observed by a light microscopy using hematoxylin & eosin staining. Weights of the reproductive and accessory organs progressively declined after the EDS treatments (weeks 1, 2 and 3). After this, the decrease was stopped, then gradually returned to the normal levels. There was a partial (about 60%) recovery of the epididymis weight during weeks $6{\sim}7$. The cross section of epididymis revealed an increase in thickness of the epithelium during weeks $1{\sim}3$. In contrast, considerable reduction of epithelial thickness in seminal vesicle was observed during same period. Similarly, a reduction in thickness of prostate epithelial layer was found during weeks $1{\sim}3$, then it was back to normal thickness after week 4. Taken together, the present study demonstrated that the temporally induced androgen-deficiency by EDS treatment could result the prominent alterations in histology of the accessory sex organs. Further studies on the physiological and molecular regulation of these androgen-sensitive organs using EDS model will be helpful to understand the normal and pathological development and differentiation mechanism of these organs.

• Development and Reproduction
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• v.11 no.1
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• pp.49-54
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• 2007

Ethane 1,2-dimethane sulfonate(EDS), a toxin which specifically kills Leydig cells(LC), has been widely used to prepare the reversible testosterone(T) depletion rat model. In the present study, we monitored the gene expression profiles of pituitary gonadotropins, LH and FSH, up to 7 weeks after EDS injection. Adult male Sprague-Dawley rats($300{\sim}350\;g$ B.W.) were injected with a single dose of EDS(75 mg/kg i.p.) and sacrificed on weeks 0, 1, 2, 3, 4, 5, 6 and 7. Total RNAs were purified from each pituitary, and the message levels of common alpha subunit($C{\alpha}$) of pituitary glycoprotein hormones, LH beta subunit($LH{\beta}$), FSH beta subunit($FSH{\beta}$) and GnRH receptor(GnRH-R) were evaluated by semi-quantitative RT-PCRs. The message levels of $C{\alpha}$ increased sharply during weeks 1-4, then return to the control level on week 5. The mRNA levels of $LH{\beta}$ were elevated after week 2, reached the peak at week 4, then declined to the control level after week 5. The message levels of $FSH{\beta}$ were elevated after week 2, reached the peak at week 3, then declined to the nadir at week 5. Similarly, the mRNA levels of GnRH-R were elevated after week 2, reached the peak at week 3, then gradually declined to the control level after week 5. The present study indicated that EDS treatment could induce reversible alterations in the transcriptional activities of gonadotropin subunits and GnRH-R in the anterior pituitary from male rats. EDS injection model might be useful to understand the mechanism of hormonal regulation of hypothalamus- pituitary neuroendocrine axis in male rats.

• Development and Reproduction
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• v.11 no.3
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• pp.187-193
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• 2007

Ethane 1,2-dimethane sulfonate(EDS), a Leydig cell specific toxicant, has been widely used to create the reversible testosterone withdrawal rat model. Though the maintenance of epididymal structure and function is highly dependent on the testosterone secreted from testis, its derivatives, dihydroxytestosterone(DHT) and estrogen, might have crucial roles. The aim of present study was to monitor the expression patterns of sex steroid receptors, cytochrome P450 aromatase(P450arom) and $5{\alpha}$-reductase in the rat epididymis up to 7 weeks after EDS injection. Adult male rats($350{\sim}400g$) were injected with a single does of EDS(75 mg/kg i.p.) and sacrificed on weeks 0, 1, 2, 3, 4, 5, 6 and 7. The transcriptional activities of the target genes were evaluated by semi-quantitative RT-PCRs. The transcript level of estrogen receptor alpha($ER{\alpha}$) in EDS group was significantly higher than control level on week 1(P<0.01). After week 2, there was no significant difference in $ER{\alpha}$ levels between EDS group and control. The transcript level of estrogen receptor beta($ER{\beta}$) in EDS group was significantly higher than control level on week 1(P<0.05), lowered on weeks 2 and 3(P<0.05 and P<0.01, respectively), fluctuated during weeks 4 and 6, and elevated on week 7(P<0.05). The androgen receptor (AR) message levels increased significantly week 2(P<0.01), then returned to control level on week 3. In contrast, expression of cytochrome P450 aromatase(P450arom) decreased sharply during weeks $1{\sim}3$(P<0.01 on weeks 1 and 2; P<0.05 on week 3), then went back to control level on week 4. The mRNA level of $5{\alpha}$-reductase type 2($5{\alpha}$-RT2) increased significantly on week 4(P<0.01), then returned to control level. The present study indicated that EDS administration could induce reversible alterations in the transcriptional activities of sex steroid hormone receptors and androgenconverting enzymes in rat epididymis. EDS injection model will be useful to clarify the regulation mechanism of mammalian epididymal physiology.