• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.3
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• pp.254-261
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• 2000

The present study has attempted to look into the mechanism of ras-induced carcinogenesis in a human epithelial cell system. Human epithelial cells immortalized with Ad12-SV40 hybrid virus were used to assess carcinogenic potential of the ras-oncogene. Cells transfected with pSV2-ras showed characteristics of cellular transformation. The transformation parameters such as cell density, soft-agar colony formation, and cell aggregation were significantly increased in the cells expressing ras oncoprotein. In addition, the duration required for the appearance of foci was shortened in the ras-transfected cells. Consistent with other reports, our results demonstrated an evidence that the ras-oncogene induced the cellular transformation of human epithelial cell system. When a high concentration of glucocorticoid was added into the media, transformation process was accelerated. It is speculated that glucocorticoid may provide an advantageous environment for the proliferation of the transformed cells. The induction of the intracellular free calcium concentrations following agonist treatment was significantly lower in the transformed cells than in the control cells. These effects were more manifested in the presence of extracellular cacium, indicating that the transformation process may alter the influx pathway of extracellular calcium. The induction of $IP_3$ following agonist treatment was also lower in the transformed cells than in the control cells. Thus, it is suggested that phospholipase C-coupled pathway was down-regulated in the process of the ras-induced transformation. While the levels of $TGF-{\beta}_1$ and PAI-2 mRNAs were decreased, the level of fibronectin mRNA was increased. The results indicate that mechanism of the ras-induced transformation may be associated with the altered expressions of growth regulatory factors. The present study demonstrates an evidence that the ras-induced cellular transformation may be associated with alteration of signal transduction and growth regulatory factors. The study will contribute to improve the understanding of molecular mechanism of epithelium-derived cancers including oral cancer.

• Journal of Embryo Transfer
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• v.20 no.3
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• pp.191-200
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• 2005

Many studies have shown that the development of mouse early 2-cell embryos in vitro is related with the intracellular $Ca^{2+}$ changes. In ICR strain mouse, the development of embryos arrests at early 2-cell stage, but the arrested early 2-cell embryos can be rescued by the addition of $Ca^{2+}$-related materials. Acetylcholine (ACh) increases intracellular $Ca^{2+}$ concentration ([$Ca^{2+}$]i) via the mAChR-PLC-IP3 pathway in mouse oocytes. We examined whether ACh rescues 2-cell block in mouse. In early 2-cell embryos, ACh increased [$Ca^{2+}$]i in a dose-dependent manner (p<0.001), and had an effect on rescue of 2-cell block and embryonic development. To identify the signal pathway involved in ACh-induced rescue of 2-cell block, we first applied an agonist of ACh receptor (AChR). Like ACh, carbachol increased intracellular $Ca^{2+}$ concentration ([$Ca^{2+}$]i) and atropine, an antagonist of ACh receptor, blocked the ACh-induced $Ca^{2+}$ increase. In $Ca^{2+}$-free medium, ACh also increased [$Ca^{2+}$]i, indicating that $Ca^{2+}$ increased by ACh is mainly released from the intracellular $Ca^{2+}$ store. The ACh-induced $Ca^{2+}$ increase was blocked by PLC inhibitor (U73122), ryanodine receptor (RyR) antagonist (dantrolene), and CaM KII inhibitor (KN-93), but not by IP3R antagonists (xestospongin C). These results show that ACh increases intracellular $Ca^{2+}$ concentration via mAChR/PLC/RyR, and this contributes to the rescue of 2-cell block.

• Korean Journal of Veterinary Research
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• v.41 no.3
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• pp.319-325
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• 2001

Several recent studies demonstrate that cAMP accumulation evokes marked changes in magnesium ($Mg^{2+}$) homeostasis. The goal of this study was to investigate the effect of melatonin, the principal hormone of the vertebral pineal gland, on $Mg^{2+}$ regulation in perfused guinea pig hearts. We hypothesized that melationin would regulate $Mg^{2+}$ efflux induced by adrenergic drugs and cAMP analogues because melatonin inhibites adneylate cyclase (AC) and phospholipase C(PLC) in the hearts. The $Mg^{2+}$ content in the perfusate was significantly higher in the presence than in the absence of melatonin. The addition of forskolin, isoproterenol or dimaprit to perfused hearts induced a marked $Mg^{2+}$ efflux. These effluxes were not inhibited by melatonin. The $Mg^{2+}$ efflux could also be induced by phenylephrine, a ${\alpha}_1$-adrenoceptor agonist. This phenylephrine-induced $Mg^{2+}$ efflux was inhibited by melatonin. In addition, the phenylephrine-induced $Mg^{2+}$ efflux was potentiated by PMA, a protein kinase C(PKC) activator. This $Mg^{2+}$ efflux was inhibited by melatonin. In conclusion, these data suggest that melatonin regulates $Mg^{2+}$ homeostasis and the inhibitory effect of melatonin on ${\alpha}_1$-adrenoceptor-stimulated $Mg^{2+}$ efflux may occur through an inhibition of PLC pathway in perfused guinea pig hearts.

• Korean Journal of Veterinary Research
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• v.55 no.4
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• pp.233-240
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• 2015

Although the effects of the rice bran have recently been investigated, there is no information regarding platelet physiology available. However, it is well known that fermented natural plants have a beneficial effect on cardiovascular diseases. Therefore, this study was conducted to investigate whether fermented rice bran extract (FRBE) with several plants (Artemisia princeps, Angelica Gigantis Radix, Cnidium officinale, and Camellia sinensis) affected agonist-induced platelet aggregation, and if so, what the underlying mechanism of its activity was. We performed several experiments, including in vitro platelet aggregation, intracellular calcium concentration and adenosine triphosphate release. In addition, the activation of integrin ${\alpha}_{II}b{\beta}3$ was determined using fibrinogen binding. Thrombus formation was also evaluated in vivo using an arterio-venous shunt model. The FRBE inhibited collagen-induced platelet aggregation in a concentration-dependent manner. FRBE significantly and dose dependently attenuated thrombus formation using rat arterio-venous shunt. FRBE suppressed the intracellular calcium mobilization in collagen-stimulated platelets. We also found that FRBE inhibited extracellular stimuli-responsive kinase 1/2, p38-mitogen-activated protein kinases and c-Jun N-terminal kinase phosphorylation. These results suggested that FRBE inhibited collagen-induced platelet aggregation, which was mediated by modulation of downstream signaling molecules. In conclusion, FRBE could be developed as a functional food against aberrant platelet activation-related cardiovascular diseases.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.6
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• pp.374-379
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• 2007

Two experiments were designed to examine short-term effects of human chorionic gonadotropin (hCG), and long-term effects of gonadotropin-releasing hormone agonist (GnRHa), $17{\alpha}-hydroxyprogesterone$ (17P), and $17{\alpha},20{\beta}-dihydroxy-4-pregnen-3-one\;(17,20{\beta}P)$, alone or in combination, on milt production of the starry flounder Platichthys stellatus. In the first experiment, fish were injected with either 200 IU hCG/kg body weight or the same volume of marine fish Ringer's solution (MFRS). In the second experiment, each fish was implanted with a blank cholesterol pellet (control), $200\;{\mu}g$ GnRHa, $500\;{\mu}g$ 17P, or $100\;{\mu}g\;17,20{\beta}P/kg$ body weight alone or in combination. In the first experiment, hCG injection resulted in an increase in the expressible milt volume and a decrease in the spermatocrit (Sct). After pellet implantation in the second experiment, the milt volume was increased in males treated with GnRHa, GnRHa+17P, or $GnRHa+17,20{\beta}P$. On day 7 after hormone pellet implantation, the milt volume began to increase, and on day 14, the milt volume in the $GnRHa+500\;{\mu}g$ 17P group was significantly higher than that in the control group. Compared with the control group, the hormone pellet-treated groups had a significant reduction in the mean Sct and sperm concentration (Sc) at day 7 after pellet implantation, while there were no differences in total sperm number. The results suggest that increases in milt volume are generally associated with decreases in Sct and SC, suggesting that the main mechanism for the increase in milt volume was milt hydration.

• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.6
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• pp.614-620
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• 2014

Kainic acid (KA) is a excitatory agonist causing epileptic seizure and excitotoxicity in the hippocampus. Gastrodia Elata (GE) is known to have anti-convulsant and anti-oxidant effects. This study was investigated a possible role of GE in suppressing epileptic seizure using KA-induced epilepsy mouse model. Eight-week-old male C57BL/6 mice were administrated GE (50 or 500 mg/kg) once a day for 5 days, and then injected KA (30 mg/kg) intraperitoneally. Behavioral changes in mice by KA were evaluated for 90 minutes immediately after the KA administration. Six hours after the KA administration, their brains were harvested and the expressions of glutamate decarboxylase 67 (GAD-67) and K+-Cl- cotransporter 2 (KCC2) in the hippocampus of the mice were measured by immunohistochemistry.GE delayed the onset of epileptic seizure after KA administration, suppressed the severity of the seizure and decreased the number of severe seizures dose dependently. Moreover, GAD-67 and KCC2 expressions in the cornu ammonis (CA) 1 and CA3 of 500 mg/kg GE administrated mice were significantly increased compared to those in KA-treated mice.GAD-67 and KCC2 play an important role in regulating GABAergic system. Our results suggest that GE has anti-convulsant effect against KA-induced epileptic seizure through enhancing GABAergic system.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.1
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• pp.1-10
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• 2008

Oral squamous cell carcinoma (OSCC) is the most frequent form of oral cancer and holds the eighth position in the cancer incidence ranking. OSCC patients are treated by classical therapeutic modalities consisting of surgery, radiotherapy, and/or chemotherapy. But OSCC still shows significant mortality rates. Thus, new therapeutic approaches have been investigated and the most promising one is naturally acquired agents with known anti-cancer effects. Genistein is a compound extracted from soy bean. Its anti-cancer effect on breast cancer is well established now and it is investigated whether it has similar effect on OSCC. It inhibited the growth and invasive-ness of OSCC cells in vitro, but these effects did not work in living animals in vivo. Catechin is a compound from green tea and its anti-cancer effect on OSCC is known better than other agents. Catechin showed its anti-cancer effect in vitro via induction of apoptosis, cell cycle arrest, inhibition of growth, and down-regulation of invasion/metastasis. These effects were confirmed in vivo with mouse model. Cordycepin is one of major pharmacologically important components in Cordyceps Militaris and may exert its anti-cancer effect as an adenosine receptor agonist. In recent study, it inhibited the proliferation of OSCC cells via A3 adenosine receptor. But because there is very scarce evidence on this effect, more researches are needed on this theme.

• The Journal of Korean Obstetrics and Gynecology
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• v.19 no.2
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• pp.77-91
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• 2006

Purpose : To address the ability of Dohaekseungkitang (DST: a commonly used herb formulation in Korea, Japan and China to have anti-cancer effect on cervical carcinoma), we investigated the effects of DST on programmed cell death (apoptosis) in HeLa human cervical carcinoma cells. Methods : We cultured HeLa cell which is human metrocarcinoma cell in D-MEM included 10% fetal bovine serum(Hyclone Laboratories) below $37^{\circ}C$, 5% CO2. Then we observed apoptosis of log phage cell which is changed cultivation liquid 24 Hours periodically. Results : After the treatment of DST for 48 hours, apoptosis occurred in a dose-dependent manner. In this study, we have shown that DST induces calpain and the associated caspase-8 and -9 activations. Apoptosis was prevented by pre-incubation of the cells with the calcium cHeLator-BAPTA-AM, calcium channel blocker-Nif edipine or Ryonidine agonist-Ryonidine peptide, implicating calcium in the apoptotic process. Ubiquitous calpains (mu- and m-calpain) have been repeatedly implicated in apoptosis, especially in calcium-related apoptosis. However this study showed 1hat either calpain inhibitor-calpastin or caspase-3 inhibitor-DEVD- did not blocked the herb formulation-induced apoptosis in HeLa human cervical carcinoma cells. D ST initiates a cell death pathway that is partially dependent of caspases. DST-induced apoptosis requires caspase-independent mechanism. Conclusion : We conclude that DST-induced calpain activation triggers the intrinsic apoptotic pathway in which caspase-independent mechanism is also involved.

• Archives of Pharmacal Research
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• v.21 no.4
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• pp.423-428
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• 1998

The ligand binding signals to a wide variety of seven transmembrane cell surface receptors are transduced into intracellular signals through heterotrimeric G-proteins. Recently, there have been reports which show diverse coupling patterns of ligand-activated receptors to the members of Gq family $\alpha$ subunits. In order to shed some light on these complex signal processing networks, interactions between G$\alpha$q family of G protein and neurokinin-2 receptor as well as muscarinic M$_{1}$ receptor, which are considered to be new thearpeutic targets in asthma, were studied. Using washed membranes from Cos-7 cells co-transfected with different G.alpha.q and receptor cDNAs, the receptors were stimulated with various concentrations of carbachol and neurokinin A and the agonist-dependent release of [$^3H$]inositol phosphates through phospholipase C beta-1 activation was measured. Differential coupling of Gaq family of G-protein to muscarinic M$_{1}$ receptor and neurokinin-2 receptor was observed. The neurokinin-2 receptor shows a ligand-mediated response in membranes co-transfected with G$\alpha$q, G$\alpha$11 and G$\alpha$14 but not G$\alpha$16 and the ability of the muscarinic $M_1$ receptor to activate phospholipase C through G$\alpha$/11 but not G$\alpha$14 and G$\alpha$16 was demonstrated. Clearly G$\alpha$/11 can couple $\M_1$ and neurokinin-2 receptor to activate phospholipase C. But, there are differences in the relative coupling of the G$\alpha$14 and G$\alpha$16 subunits to these receptors.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.246-246
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• 1996

The glucuronide conjugates of morphine have been claimed to exert significant neuropharmacological effects. Morphine-6-glucuronide (M6G) may be a potent opioid agonist in vivo, and morphine-3-glucuronide (M3G) may act as a weak opioid antagonist. The present study addressed the permeability of the blood-brain barrier (BBB) for these metabolites compared to morphine. Tracers were prepared by enzymatic glucuronidation of U-methyl-$^3$H]-morphine. Brain uptake in rats was measured by the internal carotid artery perfusion technique and after i.v. bolus injections. In the perfusion experiments morphine showed a permeability-surface area product (PS) of 3.52${\pm}$0.61 ${\mu}$L min$\^$-1/ g$\^$-1/ Uptake seems to be mediated by passive diffusion and was not saturable by 100 ${\mu}$M morphine in the perfusate. The BBB permeability of [$^3$H]-M3G and [$^3$H]-M6G was too low to be quantified after 5 min of perfusion. Brain uptake of [$^3$H]-M3G and [$^3$H]-M6G 60 min after i.v. bolus injection reached 0.0060${\pm}$0.0003 and 0.0030${\pm}$0.0005% injected dose per g, respectively. From these brain concentrations and from the corresponding plasma concentration - time curves, BBB PS values of 0.14${\pm}$ 0.02 ${\mu}$L min$\^$-1/g$\^$-1/ and 0.11 ${\pm}$ 0.01 ${\mu}$L min$\^$-1/g$\^$-1/, respectively, were calculated. The ratio of BBB PS values is complementary to the analgesic potencies of morphine and M6G after different routes of administration. The low PS of MSG explains, why it is approximate]y equipotent to morphine after systemic injection, although it is about 2 orders of magnitude more potent than morphine after administration directly into the central nervous system.