Biomedical subjects

Ee-Hwa Kim

Publications and source records attributed to Ee-Hwa Kim.

10 recordsLinked to original sources

PubMed2002

Alcohol and nicotine administration inhibits serotonin synthesis and tryptophan hydroxylase expression in dorsal and median raphe of young rats.

Serotonin (5-hydroxytryptamine, 5-HT) has been implicated in the pathophysiology of various neuropsychiatric disorders. In the present study, the effects of alcohol and nicotine on the synthesis of 5-HT and the expression of tryptophan hydroxylase (TPH), the rate-limiting enzyme of 5-HT synthesis, in the dorsal and median raphe of young rats were investigated via immunohistochemistry. The numbers of the 5-HT-positive and TPH-positive cells were reduced by alcohol and nicotine treatment in a dose-dependent manner. Based on the results, it can be suggested that the pathogenesis of alcohol- and nicotine-induced neuropsychological disorders involves alcohol- and nicotine-induced suppression of 5-HT synthesis and TPH expression in raphe, and that this may be of particular relevance in the consumption of alcohol and nicotine during adolescence.

Aging↗

PubMed2002

Protective effect of Hypericum perforatum Linn (St. John's wort) against hydrogen peroxide-induced apoptosis on human neuroblastoma cells.

The medicinal plant Hypericum perforatum Linn, commonly known as St. John's wort, has been used as an antidepressant. To investigate whether St. John's wort possesses a protective effect against hydrogen peroxide (H(2)O(2))-induced cytotoxicity in neuronal cells, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, 4,6-diamidino-2-phenylindole staining, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay, flow cytometry analysis, DNA fragmentation assay, and caspase-3 enzyme assay were performed on SK-N-MC human neuroblastoma cells. Cells treated with H(2)O(2) exhibited several apoptotic features, while those pre-treated with St. John's wort prior to H(2)O(2) exposure showed a decreased occurrence of apoptotic features. In addition, pre-treatment with St. John's wort inhibited H(2)O(2)-induced increase in caspase-3 enzyme activity. These results suggest that St. John's wort may exert a protective effect against H(2)O(2)-induced apoptosis in human neuroblastoma cells.

Apoptosis↗

PubMed2002

Hypothermia inhibits cell proliferation and nitric oxide synthase expression in rats.

In the present study, the effects of cold-water immersion on cell proliferation and nitric oxide synthase expression in the dentate gyrus of rats were investigated. Sprague-Dawley rats were divided into four groups: the control-rest group; the control-heat group; the cold-rest group; and the cold-heat group. Cold-water immersion for 5 min at 4 degrees C suppressed the numbers of 5-bromo-2'-deoxyuridine-positive and nicotinamide adenine dinucleotide phosphate-diaphorase-positive cells in the dentate gyrus, and these numbers were increased by warming for 30 min at 30 degrees C. In the present study, it was demonstrated that warming protects against cold stress-induced suppression of new cell formation, and results suggest that nitric oxide, the synthesis of which is affected adversely by cold-water immersion, may play an important role in the regulation of cell proliferation.

Animals↗

PubMed2002

Alcohol induces apoptosis in TM3 mouse Leydig cells via bax-dependent caspase-3 activation.

To investigate whether ethanol induces apoptosis in Leydig cells, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, terminal deoxynuclotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay, 4,6-diamidino-2-phenylindole (DAPI) staining, DNA fragmentation assay, caspase-3 enzyme assay, reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis were performed on TM3 mouse Leydig cells. Through morphological and biochemical analyses, it was demonstrated that TM3 cells treated with ethanol at concentrations of 50 and 100 mM exhibit classical apoptotic features. In addition, it was shown that ethanol induces increases in levels of bax and caspase-3 and a decrease in bcl-2 expression. Based on the results, alcohol appears to activate specific intracellular death-related pathways leading to bax-dependant caspase-3 activation and the induction of apoptosis in Leydig cells.

Animals↗

PubMed2002

Treadmill exercise increases cell proliferation without altering of apoptosis in dentate gyrus of Sprague-Dawley rats.

The effects of forced treadmill exercise on cell proliferation and apoptosis in the hippocampal dentate gyrus in Sprague-Dawley rats were investigated. The animals were classified into three groups: the control group, the easy exercise group, and the moderate exercise group. In the control group, rats were left on the treadmill without running for 30 min per day, while rats in the exercise groups were made to run on the treadmill for the same duration. All rats were injected intraperitoneally with 5-bromo-2'-deoxyuridine (BrdU) one-hour prior to exercise once a day for 7 consecutive days beginning at the start of the exercise regimens. Each of the rats was sacrificed 2 h after the last exercise. Both the easy and moderate exercise groups revealed increased number of BrdU-positive cells in the dentate gyrus compared to the control group. The terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay revealed very few apoptotic cells, with no statistically significant differences among the groups. These results showed that treadmill exercise increases cell proliferation without altering of apoptosis in the dentate gyrus of the hippocampus.

Animals↗

PubMed2002

Acute alcohol intoxication decreases cell proliferation and nitric oxide synthase expression in dentate gyrus of rats.

To study the dose-dependence of the effect of alcohol on cell proliferation and nitric oxide synthase expression, rats were first divided into the control group, the 0.5 g/kg alcohol-treated group, the 1 g/kg alcohol-treated group, the 2 g/kg alcohol-treated group, and the 4 g/kg alcohol-treated group. To study the duration-dependence of this effect, animals were divided into the control, the 1-day-alcohol-treated group, the 3-days-alcohol-treated group, and the 6-days alcohol-treated group; 2 g/kg of alcohol was applied to rats over the respective number of days. Alcohol injection reduced the number of both 5-bromo-2'-deoxyuridine-positive and nicotinamide adenine dinucleotide phosphate-diaphorase-positive cells in the dentate gyrus of rats in a dose- and duration-dependent manner. These results suggest that alcohol-induced impairment in memory is due to the inhibition of new cell formation, and it is possible that nitric oxide, its synthesis is affected adversely by alcohol, plays an important role in the regulation of cell proliferation.

Alcoholic Intoxication↗

PubMed2002

Acupuncture increases cell proliferation and neuropeptide Y expression in dentate gyrus of streptozotocin-induced diabetic rats.

In this study, effects of acupuncture at Zusanli acupoint on cell proliferation and expression of neuropeptide Y (NPY) in the dentate gyrus (DG) of streptozotocin-induced diabetic rats were investigated. Sprague-Dawley rats were divided into six groups: the control group, the non-diabetic and Zusanli-acupunctured group, the non-diabetic and non-acupoint-acupunctured group, the streptozotocin-induced-diabetes group, the streptozotocin-induced-diabetes and Zusanli-acupunctured group, and the streptozotocin-induced-diabetes and non-acupoint-acupunctured group. In the streptozotocin-induced diabetes group, the mean 5-bromo-2'-deoxyuridine-positive and NPY-positive cell counts in the DG were significantly decreased compared to the control group. Stimulation of the Zusanli resulted in increased cell proliferation and neuropeptide Y levels in the diabetic group. In the present results, it can be suggested that acupuncture may affect cell proliferation in the DG of streptozotocin-induced diabetic rats by regulating neuropeptide Y expression.

Acupuncture↗

PubMed2002

Nicotine administration decreases nitric oxide synthase expression in the hypothalamus of food-deprived rats.

Effect of nicotine on nitric oxide synthase (NOS) expression in various hypothalamic regions was investigated in rats via nicotineamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry. Sprague-Dawley rats were divided into the fed group, the fed and nicotine-treated group, the food-deprived group, and the food-deprived and nicotine-treated group. The fed groups received abundant food and water, while food was withheld from the food-deprived groups for 48 h. The nicotine-treated groups were injected with nicotine. Following food deprivation, enhanced NAPDH-d expression was detected in the paraventricular nucleus, ventromedial hypothalamic nucleus, and lateral hypothalamic area of the hypothalamus. Nicotine administration to the food-deprived rats resulted in decreased NADPH-d positivity. The present results indicate that nicotine administration is effective in limiting the enhancement in NOS expression following food restriction.

Animals↗

PubMed2002

Decrease of the electroacupuncture-induced analgesic effects in nuclear factor-kappa B1 knockout mice.

To investigate the involvement of nuclear factor kappa B1 (NF-kappaB1; p50/p105) in electroacupuncture (EA)-induced analgesia, 2 and 100 Hz EA stimulations were applied at acupoint ST36 (Zusanli) in NF-kappaB1 knockout mice. EA was performed for 30 min and tail-flick latencies (TFLs) were evaluated every 15 min for 1 h. Wild-type mice displayed a 63.3% increase in TFLs compared to baseline after 2 Hz EA, whereas NF-kappaB1+/- mice exhibited a 41.8% increase and NF-kappaB1-/- mice showed only a 3.9% increase of TFLs. The TFLs of 100 Hz EA showed similar trends: a 72.6% increase of TFLs in wild-type, a 38.6% increase in NF-kappaB1+/- and a 9.3% increase in NF-kappaB1-/- mice. The present findings suggest that NF-kappaB1 may play a crucial role in both low and high frequency EA-induced analgesic effects.

Analgesia↗

PubMed2002

Effects of Puerariae radix on cell proliferation and nitric oxide synthase expression in dentate gyrus of alcohol-intoxicated Sprague-Dawley rats.

Traditionally, Puerariae radix had been used for the treatment of alcohol-related problems. In this study, effects of Puerariae radix on cell proliferation and nitric oxide synthase expression in the dentate gyrus of alcohol-intoxicated Sprague-Dawley rats were investigated via 5-bromo-2'-deoxyuridine (BrdU) immunohistochemistry and nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry. Alcohol administration was shown to inhibit the numbers of both BrdU-positive and NADPH-d-positive cells, while Puerariae radix treatment was shown to increase those numbers. It is possible that nitric oxide, which might play an important role in the regulation of cell proliferation, is a major target of the toxic effects of alcohol.

Alcoholic Intoxication↗