• The Korean Journal of Physiology and Pharmacology
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• 제26권6호
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• pp.469-478
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• 2022

WNT signaling plays an important role in cardiac development, but abnormal activity is often associated with cardiac hypertrophy, myocardial infarction, remodeling, and heart failure. The effect of WNT signaling on regulation of atrial natriuretic peptide (ANP) secretion is unclear. Therefore, the purpose of this study was to investigate the effect of Wnt agonist 1 (Wnta1) on ANP secretion and mechanical dynamics in beating rat atria. Wnta1 treatment significantly increased atrial ANP secretion and pulse pressure; these effects were blocked by U73122, an antagonist of phospholipase C. U73122 also abolished the effects of Wnta1-mediated upregulation of protein kinase C (PKC) β and γ expression, and the PKC antagonist Go 6983 eliminated Wnta1-induced secretion of ANP. In addition, Wnta1 upregulated levels of phospho-transforming growth factor-β activated kinase 1 (p-TAK1), TAK1 banding 1 (TAB1) and phospho-activating transcription factor 2 (p-ATF2); these effects were blocked by both U73122 and Go 6983. Wnta1-induced ATF2 was abrogated by inhibition of TAK1. Furthermore, Wnta1 upregulated the expression of T cell factor (TCF) 3, TCF4, and lymphoid enhancer factor 1 (LEF1), and these effects were blocked by U73122 and Go 6983. Tak1 inhibition abolished the Wnta1-induced expression of TCF3, TCF4, and LEF1 and Wnta1-mediated ANP secretion and changes in mechanical dynamics. These results suggest that Wnta1 increased the secretion of ANP and mechanical dynamics in beating rat atria by activation of PKC-TAK1-ATF2-TCF3/LEF1 and TCF4/LEF1 signaling mainly via the WNT/Ca²⁺ pathway. It is also suggested that WNT-ANP signaling is implicated in cardiac physiology and pathophysiology.

• The Korean Journal of Physiology
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• 제10권1호
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• pp.7-14
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• 1976

The Present study was conducted to investigate the effects of Ginseng extract on the tension-area curve for stearic acid monolayer. At the same time, the effects of Ginseng extract on osmotic and mechanical fragility of human red cells and histamine release from rabbit leukocytes were studied, The results are summarized as follows. 1. The Ginseng alcohol extract was found to expand liquid expanded phase of stearic acid monolayer, thus it is speculated that this agent may be acting as a surface active substance. 2. Osmotic hemolysis was inhibited by the Ginseng alcohol extract and the same effect was also observed in the presence of Ginseng saponin. However, the Ginseng alcohol extract was found to decrease hematocrit ratio of the RBC suspension, therefore, the inhibition of the osmotic hemolysis by this agent may be secondary effect to the reduced cell volume. 3. The mechanical hemolysis was also inhibited by the Ginseng alcohol extract but the inhibition was independent of changes in hematocrit ratio. 4. Histamine release from rabbit leukocytes was significantly increased in vitro in the presence of the Ginseng alcohol extract.(p<0.05)

• The Korean Journal of Physiology and Pharmacology
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• 제2권5호
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• pp.581-589
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• 1998

A regulating mechanism of the ATP-sensitive potassium channels $(K_{ATP}\;channels)$ is yet to fully explained. This study was carried out to investigate the effects of intracellular application of monocarboxylates (acetate, formate, lactate, and pyruvate) on $K_{ATP}$ channels in isolated rabbit ventricular myocytes. Single channel currents of $K_{ATP}$ channels were recorded using the excised inside-out or permeabilized attached (open-cell) patch-clamp technique at room temperature. Intracellular application of acetate, formate and pyruvate led to an inhibition of channel activity, whereas intracellular application of lactate increased channel activity. These effects were reversible upon washout. Analysis of single channel kinetics showed that monocarboxylates did not affect open-time constant and close-time constant. These results suggest that monocarboxylates participate in modulating $K_{ATP}$ channels activity in cardiac cells and that modulation of $K_{ATP}$ channels activity may resolve the discrepancy between the low $K_i$ in excised membrane patches and high levels of intracellular ATP concentration during myocardial ischemia or hypoxia.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 2003년도 추계 총회 및 학술대회
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• pp.38-39
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• 2003

• Journal of Microbiology
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• 제45권5호
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• pp.373-378
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• 2007

Based on observations that lactic acid bacteria have the ability to activate macrophages, we assessed the potential effects of eight different Lactobacillus strains treated with gastrointestinal enzymes on the production of nitric oxide and various cytokines in macrophages. RAW 264.7 murine macrophage cells were cultured with either precipitates or supernatants of Lactobacillus strains digested with pepsin followed by pancreatin. The increased production of nitric oxide and interleukin $(IL)-1{\beta}$, IL-6, IL-12 and tumour necrosis factor $(TNF)-{\alpha}$ were observed when cultured with precipitates, and this effect was largely strain-dependent. In contrast, the exposure of RAW 264.7 cells to supernatants produced weaker or nearly undetectable effects in comparison to the effects of exposure to precipitates. The induction of nitric oxide appeared to be unaffected. These results demonstrate that nitric oxide and cytokines were effectively induced when the bacterial precipitate was treated with macrophages. The results of the present study also indicate that Lactobacillus strains treated with digestive enzymes are capable of stimulating the production of nitric oxide and cytokines in macrophages, which may modulate the gastrointestinal immune function of the host when it is given as a feed additive.

• Asian-Australasian Journal of Animal Sciences
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• 제23권12호
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• pp.1608-1613
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• 2010

This study was designed to investigate the effects of supplementation of spent mushroom substrates (SMS) on rumen fermentation and blood metabolites in Hanwoo steers. The experiment was conducted as a duplicated Latin square design with six Hanwoo steers ($600{\pm}47\;kg$), each permanently fitted with a ruminal cannula. There were three treatments; i) control (concentrates 4.8 kg +rice straw 1.2 kg/d), ii) Pleurotus eryngiia (PE) treatment (concentrates 4.8 kg+rice straw 0.73 kg+Pleurotus eryngiia 1.20 kg/d) and iii) Pleurotus osteratus (PO) treatment (concentrates 4.8 kg+rice straw 0.73 kg+Pleurotus osteratus 1.20 kg/d). There were no major effects of different dietary treatments on rumen parameters such as pH, ammonia-N, individual and total VFA production. Parameters of N utilization, including blood urea nitrogen (BUN), total protein and albumin levels, were not significantly different among the treatments, except for creatinine. Thus, the present results indicated that protein utilization was mostly unaffected by SMS treatments such as PE and PO, even though creatinine concentration was lower in PE compared with control and PO treatments (p<0.05). The present results indicate that Pleurotus eryngii and Pleurotus osteratus could be used as a forage source to replace 40% of rice straw without any negative effects on rumen fermentation and blood metabolites in Hanwoo steers.

• 대한약침학회지
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• 제20권3호
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• pp.201-206
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• 2017

Objectives: The aim of this study was to investigate the effects of Cassia acutifolia on the obesity and the glucose levels in a rat model of obesity and diabetes. Methods: By random selection, 36 Wistar male rats were divided in two control groups, the positive and the negative control groups, and into four experimental groups receiving different infusions of Cassia acutifolia in water ad libitum. Results: The results revealed a statistically significant anti-obesogenic effect (P = 0.02), although this was not considered clinically significant. Additionally, Cassia acutifolia lowered the glucose levels by 30 mg/dL to 90 mg/dL (P = 0.05). However, we observed adverse effects in the liver, a two-fold increase in transaminase levels (P = 0.002), and in the kidneys, decreased creatinine levels (P = 0.001), and these adverse effects had no viable explanation. Conclusion: Cassia acutifolia has anti-hyperglycemic effects in obese diabetic rats. However, Cassia acutifolia also has adverse effects, so it should not be administered to patients.

• The Korean Journal of Physiology
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• 제28권1호
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• pp.105-111
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• 1994

The present study was carried out to determine the effects of intracisternal administration of three doses of bombesin $(0.001,\;0.01\;and\;0.1\;{\mu}g)$ on afferent somatosensory transmission in single neurons of the spinal trigeminal nucleus of anesthetized rats. Lower doses $(0.001\;{\mu}g)$ of bombegin did not change the afferent sensory transmission. Medium doses $(0.01\;{\mu}g)$ of bombesin significantly (p p<0.01) facilitated afferent sensory transmission in the 6 to 30 min post-drug period, but higher doses $(0.1\;{\mu}g)$ inhibited responsiveness of spinal trigeminal neurons in the 16 to 35 min post-drug period. The results indicate that endogenous bombesin-like peptide present in the spinal trigeminal nucleus may participate in the processing of the somatosensory information arising from the face.

• The Korean Journal of Physiology
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• 제6권1호
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• pp.27-31
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• 1972

The activity of Mg and Na-K activated ATPase of homogenate from rat brain cortex was measured in vitro under the variety of conditions. The effects of various hypnotic and tranquilizer such as phenobarbital, amobarbital, diazepam, promazine and chlorpromazine on the activities of both ATPase was investigated and the results was summarized as follows. 1. Na-K ATPase was slightly inhibited by phenobarbital and amobarbital while Mg ATPase was moderately activated by these drugs. 2. Both Mg and Na-K ATPase activities were markedly inhibited by diazepam. 3. Promazine and chlorpromazine markedly inhibited both Mg and Na-K ATPase activities. These findings indicate that remarkable correlation between hypnotic or tranquilizing potency and ATPase inhibition could be observed.

• The Korean Journal of Physiology and Pharmacology
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• 제6권3호
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• pp.149-154
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• 2002

The blood pressure (BP) is regulated by the nervous system and humoral factors, such as renin- angiotensin system, vasopressin and others. In the present study, we examined the central effects of glutamate and GABA on the cardiovascular regulation by injection of these substances into the lateral ventricle and also investigated the relationship between these central effects and the action of angiotensin II (Ang). Male Sprague Dawley rats, $350{\sim}400$ g, were anesthetized with urethane and instrumented with an arterial catheter for direct measurement of BP and heart rate (HR), and an guide cannula in the lateral ventricle for drug injection. A glass microelectode was inserted into the rostral ventrolateral medulla (RVLM) for recording single unit spikes. Barosensitive neurons were identified by changes of single unit spikes in RVLM following intravenous injection of nitroprusside and phenylephrine. The effects of GABA and glutamate injected into the lateral ventricle were studied in single neuronal activity of the RVLM in addition to changes in BP and heart rate, and compared the results before and after treatment with intravenous losartan, nonpeptide Ang II-type 1 receptor antagonist (1 mg/100 g BW). Intracerebroventricular administration of GABA decreased systolic blood pressure (SBP) and HR, but increased the firing rates in the RVLM. However, intracerebroventricular glutamate injection produced effects opposite to GABA. After pretreatment of intravenous losartan, the central effects of GABA on BP and firing rate in the RVLM were significantly attenuated and that of glutamate showed a tendency of attenuation. These results suggested that central GABA and glutamate regulated BP and firing rates in RVLM were inversely related to BP change. The central effects of GABA or glutamate on the autonomic nervous function were modulated by humoral factor, Ang II, by maintaining BP.