• Clinical and Experimental Reproductive Medicine
• /
• v.40 no.4
• /
• pp.155-162
• /
• 2013

Objective: Stress is known to be an inhibitor of the reproductive hypothalamic-pituitary-gonadal (HPG) axis. However, the neural and molecular connections between stress and reproduction are not yet understood. It is well established that in both humans and rodents, kisspeptin (encoded by the kiss1 gene) is a strong stimulator of the HPG axis. In the present study we hypothesized that endocannabinoids, an important neuromodulatory system in the brain, can act on the HPG axis at the level of kiss1 expression to inhibit reproductive function under stress. Methods: Adult male Wistar rats were unilaterally implanted with an intracerebroventricular cannula. Afterwards, the animals were exposed to immobilization stress, with or without the presence of the cannabinoid CB1 receptor antagonist AM251 (1 ${\mu}g/rat$). Blood samples were collected through a retro-orbital plexus puncture before and after stress. Five hours after the stress, brain tissue was collected for reverse transcriptase-quantitative polymerase chain reaction measurements of kiss1 mRNA. Results: Immobilization stress (1 hour) resulted in a decrease in the serum luteinizing hormone concentration. Additionally, kiss1 gene expression was decreased in key hypothalamic nuclei that regulate gonadotrophin secretion, the medial preoptic area (mPOA), and to some extent the arcuate nucleus (ARC). A single central administration of AM251 was effective in blocking these inhibitory responses. Conclusion: These findings suggest that endocannabinoids mediate, at least in part, immobilization stress-induced inhibition of the reproductive system. Our data suggest that the connection between immobilization stress and the HPG axis is kiss1 expression in the mPOA rather than the ARC.

• Korean Journal of Bronchoesophagology
• /
• v.14 no.2
• /
• pp.43-47
• /
• 2008

Background : Anti-reflux procedures treat gastroesophageal reflux (GER) disease. It is known that gastroesophageal reflux is likelyrelated to the increased incidence of chronic rejection in lung transplantation recipients. Because experimental animal studies areto verify this, we have tried to make an animal model of GER in a rat. Material and Methods : Using the SD rats weighing 250-300 g, we surgically induced gastroesophageal reflux and measured the gastrostomy time under anesthesia. Of three groups, Group I was the control, Group II had lower esophageal and anterior myotomy, and Group III had lower esophageal and anterior myotomy plusdiaphragmatic crural myotomy.The animals were scarified, and lung biopsies and histological examinations were performed 1 week, 2 weeks, 4 weeks, 8 weeks and 3 months after gastroesophageal reflux surgery. Results : Baseline animals (n=5) had no GER after charcoal instillation through a gastrostomy tube in Group I. Charcoal-laden macrophages were observed in GroupsII and III. To determine evidence of GER evidence, charcoal was instillated through the gastrostomy tube in group III. In contrast, Group II demonstrated severe neurophil infiltration in the bronchioles and alveolar walls after procedure. After 12 weeks, we observed the disappearance of neurophil, lymphocyte and histiocyte infiltration, and also occasional focal bronchopneumonia and bronchitis. Group III demonstrated neurophil and basophil infiltration in the bronchioles and alveolar walls which was more severe than that in Group II. Interstitial fibrotic changes were observed in Group III.Conclusion : The purpose of our gastroesophageal reflux model was to find evidence of aspiration. There was more evidence of aspiration in Group II than in either of theother two groups.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.24 no.6
• /
• pp.837-842
• /
• 1995

Hot red pepper(Capsicum annum L.) has been extensively used as a spicy food additive and preservative in Korea. In this study, we investigated the effect of dietary hot red pepper powder on humoral immune response in rats. Sprague-Dawley rats were divided into 4 groups and fed experimental diets containing 0, 2, 5, 10% hot red pepper powder for 27 days. All groups were immunized with sheep red blood cells. In order to measure the immune response, plaque-forming cell number, agglutination titer, and serum antibody level were measured. Tissue ascorbic acid contents were also determined by high-performance liquid chromatogrphy. There was an increased plaque-forming cell number, agglutination titer, and serum IgG level in the groups supplemented with hot red pepper powder as compared to control. Tissure ascorbic acid contents in the hot pepper powder supplemented group were higher than those of control. The results suggest that the dietary hot red pepper powder enhances humoral immune response in rats, indicating that the hot pepper contains biological response modifier.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.28 no.3
• /
• pp.646-653
• /
• 1999

This study was done to investigate the effect of ${\gamma}$ irradiated beef feeding on antioxidant vitamin levels and defense enzyme activities in diethylnitrosamine(DEN) initiated rats. Weaning Sprague Dawley male rats were fed the diet containing ${\gamma}$ irradiated ground beef at the dose 0, 3, 5 kGy as a 20% of protein source for 8 weeks. One week after feeding, rats were intraperitoneally injected twice with a dose of DEN(50mg/kg BW). As a promoter, 0.05% phenobarbital was fed in drinking water from one week after DEN treatment until the end of experiment. At the end of 8th week, serum level of vitamin C, serum and hepatic levels of retinol and tocopherol were determined. In addition, activities of cytosolic glutathione peroxidase, glutathione reductase, glutathione S transferase, catalase and hepatic superoxide dismutase(SOD) were measured. By ${\gamma}$ irradiation, there was no significant effect on serum and hepatic levels of vitamin C and tocopherol except a significant decreasing effect on hepatic retinol level. There was also no significant effect on the activities of enzymes involved in antioxidative defense system, However, DEN treatment led to a significant increase in activities of glutathione reductase and glutathione S transferase while the activity of glutathione peroxidase was decreased. The activities of hepatic SOD and catalase were not changed by DEN treatment. Overall results indicate that the consumption of low dose of ${\gamma}$ irradiated beef does not affect antioxidative defense system.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.28 no.3
• /
• pp.663-669
• /
• 1999

The purpose of this study was to investigate the effects of vitamin E on the histochemical change of kidney tissue in diabetic rats. Sprague Dawley male rats weighing 100$\pm$10g were randomly assigned to one normal and three STZ induced diabetic groups, which were subdivided into vitamin E free diet(DM 0E group), 40mg vitamin E per kg diet(DM 40E group) and 400mg vitamin E per kg diet(DM 400E group). Vitamin E level of normal group was 40mg per kg diet. Diabetes was exper imentally induced by intravenous injection of 55mg/kg of body weight of streptozotocin(STZ) in citrate buffer(pH 4.3) after 4 weeks feeding of experimental diets. Animals were sacrificed at the 6th day of diabetic states. The contents of thiobarbituric acid(TBARS) in kidney were increased 119%, 84% and 33% in DM 0E, DM 40E and DM 400E groups, respectively, compared to normal group. That of DM 400E group was decreased 39% compared to DM 0E group. Content of 2 microglobulin in urine in DM 0E, DM 40E, and DM 400E groups were increased by 248%, 181%, and 164%, respectively, compared to normal group. The diabetic groups showed the regressive lesion such as renal tubule, intumescence of epithelial cell, vacuolization. The results of the observation through electronic microscope showed the mitochondria shape of proximal tubule epithelial cell, irregular array, increase of ribosome, and irregular arrangement of small villosity, etc. These types of changes appeared severer in DM 0E group than in DM 400E group. These results indicate that the TBARS productions on kdney in STZ induced diabetic rats were increased, consequently those leaded to damage of renal tubule and minuteness structure. But a large quantity vitimin E supplementation was suppressed in TBARS production and improved in peroxidative damage of renal tissue so that relieved degenerative changes of renal tubule epithelial cell.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.21 no.6
• /
• pp.1415-1423
• /
• 2007

Carbon tetrachloride ($CCl_4$)-induced liver injury depends on a toxic agent that has to be metabolized by the liver NAPDH-cytochrome P450 enzyme system to a highly reactive intermediate. Alternations in the activity of cytochrome P450 enzymes affect the susceptibility to hepatic injury from $CCl_4$. In this study, we evaluated the potential protective activity of the traditional Korean medicinal herb, Corni fructus (CF), against an experimental model of hepatotoxicity induced by $CCl_4$. The CF exhibited a hepatoprotective activity against $CCl_4-induced$ liver damage in Sprague-Dawley (SD) rats, as measured by GOT, GPT, ALP and histological observation. The CF also showed significant decrease of malodialdehyde (MDA) and increase of glutathion (GSH), catalase activity in rat liver homogenate. In addition, the expression of CYP2E1, as measured by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot analysis, was significantly decreased in the liver of CF treated SD rats. But $CCl_4$ and CF has no significant effect on 1A1 and 3A1 isoform of cytochrome P450. Based on these findings, it is suggested that hepatoprotective effects of CF possibly related to antioxidative effects and regulation of CYP2E1 expression.

• The Korean Journal of Physiology and Pharmacology
• /
• v.10 no.5
• /
• pp.255-261
• /
• 2006

Melittin-induced nociceptive responses are mediated by selective activation of capsaicin-sensitive primary afferent fibers and are modulated by excitatory amino acid receptor, cyclooxygenase, protein kinase C and serotonin receptor. The present study was undertaken to investigate the peripheral and spinal actions of voltage-gated calcium channel antagonists on melittin-induced nociceptive responses. Changes in mechanical threshold and number of flinchings were measured after intraplantar (i.pl.) injection of melittin $(30\;{\mu}g/paw)$ into mid-plantar area of hindpaw. L-type calcium channel antagonists, verapamil [intrathecal (i.t.), 6 or $12\;{\mu}g$; i.pl.,100 & $200\;{\mu}g$; i.p., 10 or 30 mg], N-type calcium channel blocker, ${\omega}-conotoxin$ GVIA (i.t., 0.1 or $0.5\;{\mu}g$; i.pl., $5\;{\mu}g$) and P-type calcium channel antagonist, ${\omega}-agatoxin$ IVA (i.t., $0.5\;{\mu}g$; i.pl., $5\;{\mu}g$) were administered 20 min before or 60 min after i.pl. injection of melittin. Intraplantar pre-treatment and i.t. pre- or post-treatment of verapamil and ${\omega}-conotoxin$ GVIA dose-dependently attenuated the reduction of mechanical threshold, and melittin-induced flinchings were inhibited by i.pl. or i.t. pre-treatment of both antagonists. P-type calcium channel blocker, ${\omega}-agatoxin$ IVA, had significant inhibitory action on flinching behaviors, but had a limited effect on melittin-induced decrease in mechanical threshold. These experimental findings suggest that verapamil and ${\omega}-conotoxin$ GVIA can inhibit the development and maintenance of melittin-induced nociceptive responses.

• The Korean Journal of Physiology and Pharmacology
• /
• v.12 no.5
• /
• pp.237-243
• /
• 2008

Intraplantar injection of melittin has been known to induce sustained decrease of mechanical threshold and increase of spontaneous flinchings. The present study was undertaken to investigate how the melittin-induced nociceptive responses were modulated by changes of metabotropic glutamate receptor (mGluR) activity. Changes in paw withdrawal threshold (PWT), number of flinchings and paw thickness were measured at a given time point after injection of melittin ($10{\mu}g$/paw) into the mid-plantar area of rat hindpaw. To observe the effects of mGluRs on the melittin-induced nociceptions, group I mGluR (AIDA, $100{\mu}g$ and $200{\mu}g$), $mGluR_1$ (LY367385, $50{\mu}g$ and $100{\mu}g$) and $mGluR_5$ (MPEP, $200{\mu}g$ and $300{\mu}g$) antagonists, group II (APDC, $100{\mu}g$ and $200{\mu}g$) and III (L-SOP, $100{\mu}g$ and $200{\mu}g$) agonists were intrathecally administered 20 min before melittin injection. Intraplantar injection of melittin induced a sustained decrease of mechanical threshold, spontaneous flinchings and edema. The effects of melittin to reduce mechanical threshold and to induce spontaneous flinchings were significantly suppressed following intrathecal pre-administration of group I mGluR, $mGluR_1$ and $mGluR_5$ antagonists, group II and III mGluR agonists. Group I mGluR antagonists and group II and III mGluR agonists had no significant effect on melittin-induced edema. These experimental findings indicate that multiple spinal mGluRs are involved in the modulation of melittin-induced nociceptive responses.

• The Journal of Korean Obstetrics and Gynecology
• /
• v.18 no.1
• /
• pp.64-80
• /
• 2005

The pharmacological effects of medicinal remedies traditionally used in Asian countries for improving the blood circulation were examined on isolated rat thoracic aorta strips in organ baths. Each experimental medicine was consecutively extracted under reflux with water. Of 17 plants, Curcuma longa (CL) having the strongest acute relaxant activity in endothelium-intact arteries, Mucunae caulis (MC), Cirsium pendulum (CP), Rumex longiflius (RL), Paeonia suffruticosa (PS), Curcuma zedoaria (CZ), Scirpus maritimus (SM), Siphonostegia chinensis (SC), Leonurs sibiricus (LS) and Typha orientalis (TO) were showing dose-dependent relaxant activity. Long-term relaxant effects were showed in Curcuma aromatia (CA), MC, CP, RL, PS, Potulacae grandiflorae (PG), CZ, Panax notoginseng (PN), Achyranthes japonica (AJ), CL, SC, Lycoppus lucidus (LL) and Corydalis turtschaninovii (CT). In endothelium-injury test using carbachol, CL, SC, MC, RL and PS which are having the acute vasorelaxing activity and CA and CT which are not showing vasorelaxaing activity were damaged to endothelium. As a result of this study, the possibility that a part of medicinal remedy may contribute to the beneficial effects in blood circulation was proposed, but inter-individual variation has been observed. Also, further studies on the vasorelaxant effects of these remedies are still required.

• Korean Journal of Pharmacognosy
• /
• v.48 no.2
• /
• pp.97-107
• /
• 2017

There is no doubt that the effect of ginseng on blood pressure could be different depending upon the type of ginseng employed for the experiment and methodology, thereby can exert bilateral modulatory activity on blood pressure. It has been reported that ginseng induced no significant change in blood pressure in those subjects with normal blood pressure, but had a normalizing effect on the subjects with abnormal blood pressure. Especially, experimental evidence indicates that ginsenoside Rg3, a major component of red ginseng, has been found to lower blood pressure, which is mediated by release of endothelium-derived NO, enhancing the accumulation of cGMP in the rat aorta. This clinical results further support the beneficial effect of Korean ginseng on blood pressure elucidated by animal experiment. As expected, a multicentric non-controlled clinical study shows that the effect of ginseng consumption has been found to normalize blood pressure in hypertensive or hypotensive individuals as compared to virtually no effect in normotensives. In addition, ginseng has been known to exhibit blood pressure decreased with no significant side effect and deteriorated QOL during the combination therapy of ginseng and anti-hypertensive drugs. This review provides a comprehensive overview on the effects of Korean ginseng on blood pressure.