http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Streptozotocin-Induced Diabetes Decreases Vascular Endothelial Growth Factor in Rat Placenta
Phil Ok Koh 한국실험동물학회 2007 Laboratory Animal Research Vol.23 No.1
Gestational diabetes induces the abnormal placental growth and fetal development. The placenta produces several growth factors, including vascular endothelial growth factor (VEGF), which are essential for placenta growth and fetal growth. This study investigated whether diabetes in pregnant rats induces changes in VEGF expression in the placenta. Diabetes was induced by a single intravenous injection of streptozotocin (35 ㎎/㎏ body weight) on day 0 of pregnancy, blood and tissue samples were collected on day 20 of pregnancy. In the diabetic group, maternal body weight and fetal weight significantly decreased compared to controls. Western blot analyses showed that expression of VEGF was significantly decreased in placenta by streptozotocin treatment. These findings suggest that the decrease of VEGF in the placenta in diabetic pregnancy may contribute to retardation of fetal development and placental growth.
Ethanol Exposure Increases JNK Phosphorylation and bax Expression in Adult Rat Testes
Phil Ok Koh 한국실험동물학회 2006 Laboratory Animal Research Vol.22 No.3
Ethanol exposure is known to suppress male reproductive activity in laboratory animals and humans. The present study was designed to evaluate whether ethanol exposure increases JNK phosphorylation and bax activation in rat testes. Ethanol (1.5 g/㎏ or 3 g/㎏ i.p., 15% v/v in saline) was administrated to adult male rats for 10 days. Ethanol treatment was significantly increased the number of TUNEL-positive cells in rat testes. Western blot analysis showed that ethanol treatment significantly increased the level of pJNK in testes. Furthermore, the level of bax was increased in ethanol-treated rats in comparison to saline-treated rats. In conclusion, our findings suggest that ethanol induces apoptotic cell death via the phosphorylation of JNK and the activation of bax, in rat testes.
Estradiol Increases Heme Oxygenase-1 Expression in Brain Ischemic Injury
Phil-Ok Koh 한국실험동물학회 2006 Laboratory Animal Research Vol.22 No.2
This study investigated whether estradiol modulates the heme oxygenase-1 (HO-1) and HO-2 expressions in brain ischemic injury. Adult female rats were ovariectomied and treated with estradiol prior to middle cerebral artery occlusion (MCAO). Brains were collected 24 h after MCAO and infarct volumes were analyzed. Estradiol administration significant-reduced infarct volume and decreased the positive cells of TUNEL staining in the cerebral cortex. Activation of HO-1 and HO-2 was measured using Western blot analysis. Estradiol increased the level of HO-1 in ischemic injury induced by MCAO. The level of HO-1 was 0.81 ± 0.15 and 0.97 ± 0.25 in the ipsilateral cortex of oil-and estradiol-treated animals, respectively. However, the level of HO-2 was consistently maintained in the ipsilateral cortex of oil- and estradiol-treated animals. Our findings suggest that estradiol prevents cell death caused by neuronal cell injury through the increase of HO-1 expression.
Streptozotocin-Induced Diabetes Decreases Proliferating Cell Nuclear Antigen in Rat Testes
Phil-Ok Koh 한국실험동물학회 2007 Laboratory Animal Research Vol.23 No.2
Sexual dysfunction is associated with diabetes in males. The present study was designed to evaluate whether streptozotocin-induced diabetes decreases proliferative activity in rat testes. Diabetes was induced by a single intravenous injection of streptozotocin (40 ㎎/㎏ body weight). Testes samples were collected after 3 months. Testicular weight decreased in the diabetic group. Proliferating cell nuclear antigen (PCNA) was used as a proliferative marker. Western blot analysis showed that the level of PCNA significantly decreased in diabetic group, compared to that of controls. The level of PCNA was 1.12 ± 0.04 and 0.87 ± 0.11 in control and diabetic rats, respectively. Also, PCNA-positive cells in the spermatogonia and primary spermatocytes decreased in diabetic rats. The present study demonstrates that streptozotocin-induced diabetes decreases the cell proliferative activity in testes. In conclusion, our findings suggest that decrease of cell proliferation in the testes of diabetics contributes to the suppression of male reproductive activity.
Phil-Ok Koh 한국실험동물학회 2010 Laboratory Animal Research Vol.26 No.3
PEA-15 is a small phosphoprotein (15 kDa) that is enriched in brain astrocytes. PEA-15 acts as an important modulator of cellular function including apoptosis and signal integration. This study investigated the expression of PEA-15 in focal cerebral ischemic injury. Cerebral ischemia was surgically induced in adult male rats by middle cerebral artery occlusion (MCAO), and brains were collected 24 hr after MCAO. A proteomic approach demonstrated decreases of PEA-15 protein spots in MCAO-operated animals in comparison to sham-operated animals. Western blot analysis clearly demonstrated that MCAO induces decreases in PEA-15 levels. We previously showed that glutamate toxicity induces cell death in a hippocampus-derived cell line (HT22). Glutamate exposure induces decreases of PEA-15 levels in HT22 cells. The results of this study suggest that focal cerebral ischemia induces cell death through downregulation of PEA-15 protein.
Expression of placenta growth factor mRNA in the rat placenta during mid-late pregnancy
Phil-Ok Koh,Wan-Sung Choi,Gyeong-Jae Cho,Chung-Kil Won 대한수의학회 2005 Journal of Veterinary Science Vol.6 No.3
The placenta is an essential organ that synthesizes several growth and angiogenic factors for its own growth as well as fetal development. It is known that the placenta growth factor (PlGF) is a member of the vascular endothelial growth factor family and is critical for placental growth and fetal development. However, there is little information regarding the expression pattern and cellular localization of PlGF mRNA in rat placenta during pregnancy. The aim of this study was to define the distribution of PlGF mRNA in rat placenta at various gestations. RT-PCR analysis showed that the expression level of PlGF mRNA increased as gestation advanced. Using in situ hybridization histochemistry, positive cells of PlGF mRNA were detected in chorionic villi. PlGF mRNA was expressed in the trophoblast cells and stroma cells surrounding the blood vessels within chorionic villi on day 13 and 15. Also, positive signals of PlGF mRNA were strongly detected in stroma cells of chorionic villi on day 17, 19, and 21. In particular, the density and number of positive signals of PlGF mRNA was significantly increased as gestation advanced. The expression pattern of PlGF mRNA in rat placenta during pregnancy demonstrates that PlGF plays a functional role for placental growth and fetal development during mid-late pregnancy.