• Journal of Animal Science and Technology
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• v.47 no.6
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• pp.925-936
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• 2005

The present study evaluated whether pentoxifylline added to the freezing extender could improve the sperm characteristics and function in canine frozen semen. Also the conception rate following AI with frozen-thawed semen was investigated. The beneficial effects of pentoxifylline supplementation were visible in motility, viability, acrosome reaction, and tail swelling patterns. Especially, highest sperm viability and function were obtained in the forzen semen supplemented with 1mM pentoxifylline. The follicle size measured by ultrasonography was 6.48 mm, 11.52 mm and 8.9 mm on 11, 13 and 15 days after the onset of natural estrus, respectively and ovulation occurred on 13 and 15 days. The pregnancy rates in bitches inseminated with frozen semen on natural and induced estrus were 71.4% and 75.0%, respectively. There was no significant difference between the pregnancy rates in bitches inseminated with frozen semen following natural and induced estrus, but the litter size was slightly increased in natural cycle.

• Toxicological Research
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• v.33 no.2
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• pp.107-118
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• 2017

Although alternative test methods based on the 3Rs (Replacement, Reduction, Refinement) are being developed to replace animal testing in reproductive and developmental toxicology, they are still in an early stage. Consequently, we aimed to develop alternative test methods in male animals using mouse spermatogonial stem cells (mSSCs). Here, we modified the OECD TG 489 and optimized the in vitro comet assay in our previous study. This study aimed to verify the validity of in vitro tests involving mSSCs by comparing their results with those of in vivo tests using C57BL/6 mice by gavage. We selected hydroxyurea (HU), which is known to chemically induce male reproductive toxicity. The 50% inhibitory concentration ($IC_{50}$) value of HU was 0.9 mM, as determined by the MTT assay. In the in vitro comet assay, % tail DNA and Olive tail moment (OTM) after HU administration increased significantly, compared to the control. Annexin V, PI staining and TUNEL assays showed that HU caused apoptosis in mSSCs. In order to compare in vitro tests with in vivo tests, the same substances were administered to male C57BL/6 mice. Reproductive toxicity was observed at 25, 50, 100, and 200 mg/kg/day as measured by clinical measures of reduction in sperm motility and testicular weight. The comet assay, DCFH-DA assay, H&E staining, and TUNEL assay were also performed. The results of the test with C57BL/6 mice were similar to those with mSSCs for HU treatment. Finally, linear regression analysis showed a strong positive correlation between results of in vitro tests and those of in vivo. In conclusion, the present study is the first to demonstrate the effect of HU-induced DNA damage, ROS formation, and apoptosis in mSSCs. Further, the results of the current study suggest that mSSCs could be a useful model to predict male reproductive toxicity.

• Development and Reproduction
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• v.8 no.2
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• pp.77-84
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• 2004

The purpose of this experiment was to determine the effects of di(2-ethylhexyl) phthalate(DEHP) on reproductive characteristic, blood hematological and chemical values in mice. The male mice were intraperitoneally injected DEHP in negative control(no treatment), positive control(corn oil, 3ml/kg B.W), 0.5, 1.0 and 10.0mg DEHP/kg B.W and the female mice were injected DEHP in control(corn oil, 3ml/kg B.W), 0.5, 1.0 and 10.0mg DEHP/kg B.W with 5 times for 15 days on 3 days interval. The administration of DEHP in male mice were not affect on body weight, epididymis, vesicular gland and coagulating gland weight. The testis weight were slightly higher in DEHP treatment groups than in control. The semen characteristics(sperm concentration, viability, motility and abnormality) of male mice were not difference in all experimental groups. The RBC, Hb, HT, MCV, MCH, MCHC< PLT, albumin, BUN and total protein of blood hematological and chemical values were not affect the administration of DEHP in mice. The WBC values in 10.0mg DEHP group was slightly difference in all experimental group(P>0.05). The histological evaluation of testis, ovary and affevt the reproductive characteristic, blood hematological and chemical values.