• Archives of Pharmacal Research
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• 제18권5호
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• pp.301-307
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• 1995

In the particulate fraction obtained from PKC-down regulated K562 cells by treatment for 24 h with 200nM TPA, phosphorylation of two proteins with molecular weight, 100 kDa and 23 kDa (designated p100 and p23, respectvely) was depleted and addition of exogenous purified PKC to this fraction failed to testore their phosphorylation. However, in the soluble fraction, all of phosphoproteins abolished by long-term treatment with TPA were restored by exogenously added PKC. Phosphorylation of two proteins was increased by short-term tretment (20 min), and diminished with the persistant exposure to TPA as well as at a concentration as low as 1nM. When K562 cells were treated with 1 nM and 200 nM TPA for 24 h, phosphorylation of p100 was restored with or without exogenous PKC on 2-3day and 6day after removal of treated TPA, respectively. Two-dimensional electrophoresis of phosphoproteins revealed that phosphorylated p100 (pl=5.9) and p66 species were completely absent from the particulate fraction of K562 cells treated with 200nM TPA for 24 h. These results suggest that the interaction of sensitive endogenous substrates, p100 and p23 with the plasma membrane might be regulated by PKC-down regulation without displacement to the cytosol and the interaction of p100 with the membrane might be reveersible.

• 약학회지
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• 제37권6호
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• pp.571-576
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• 1993

The substrate specificity of the purified rabbit plasma alkaline phosphatase (ALPase) was determined towards a extended range of potential substrates including relatively simple phosphate derivatives as p-NPP and indolyl phosphate, and several synthetic peptides and phosphoproteins. These results further estabilish the broad substrate specificity of these circulating enzymes. Interestingly, the plasma ALPase preferentially dephosphorylates Thr over Ser residues, as demonstrated with a series of synthetic peptides. The latter result is in contradiction to the behaviour of the tissue ALPase, which is thought to the ultimate source of plasma ALPase, and open therefore new perspectives with respective to the origin and "solubilisation" processes of these enzymes. Dephsphrylation of protein substrates by endogenous and isolated plasma ALPases indicates that ALPase probably displays protein phosphatase activity in vivo.

• Journal of Plant Biology
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• 제2권1호
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• pp.1-12
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• 1959

1) The comparative studies of the quantitative measurement of growth characteristics and utilization of substrates by Euglena gracilis var. bacilla 10616 in the light and in darkness have been carried out. Eodogenous respiration, effect of respiratory inhibitors and responses to the added substrates for the exogenous respiration are also investigated. 2) All cultures are grown in the open air under the continuous illumination of fluorescent light of 3500 lux at room termperature, the growth rate of the culture in the basal medium added 0.5% lactate is found to be the highest. The growth rate decreases successively for the cultures of 0.5% sucinate, 0.5% Na-acetate, 0.5% malate, and control. There is no growth in the basal meidum added 0.5% butyrate and 0.5% hydroquinone. The similar results are obtained for the mentioned cultures in the darkness. However, the growth rate in basal medium added 0.5% glucose and 0.5% sucrose does seem to increase in the darkness unlike the illumination. 3) The endogenous rate of respiration for the organism cultured photosynthetically is about 12.94ul 02/mg/hr, in basal medium and the respiratory quotient is about 0.84. The rate is decreased by starvations to 6.5ul 02/mg/hr, about to a half, but the respiratory quotient does net change. 4) The oxygen consomption during initial 2 hours in suspending solution ranging from pH 4.5 to pH 9.3 is highest at pH 4.5 in which the algae had grown, at pH 5.5 and at pH 6.9. 5) Endogenous respiration of the cells is strongly inhibited by 0.1M of potassium cyanide, malomic acid, sodium fluoride and iodo-acetic acid. It is also strongly inhibited by 0.01M of potassium cyanide. 6) The respiratory response to added substrates for the exogenous respiration in the organism is coincided with the rate in the basal medium added the substrate in light and in darkness, whether the cells are fed or starved. 7) According to the results of this study, there seems to be the flexibility of the interconversion between photosynthesis and chemosynthesis, heterotropic mode of metabolism, in Euglena gracilis var. bacillaris, and that this organism utilizes the lactate most. It also may be suggested that the enayme systems linked in the each steps of Embden-Myerhof-Parnas path way and TCA cycle seem to exist in this organism.

• 대한약리학회지
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• 제31권1호
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• pp.53-61
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• 1995

Lidocaine의 심근 수축력 억제 기전이 적출 심장에서 내인성 기질의 사용과 관련이 있는가를 규명하기 위하여, 심장의 phosphofructokinase (PFK)에 대한 강력한 억제 작용을 나타내는 citracte와 bicarbonate-free medium을 이용하여 쥐의 적출 심방 수축성에 대한 lidocaine의 영향을 연구하여 다음과 같은 실험 결과를 얻었다. Citrate와 bicarbonate-free medium은 쥐의 적출 심방의 수축력을 현저히 저하시켰다. Pyruvate나 acetate는 citracte와 bicarbonate-free medium에서 저하된 심방 수축력을 현저히 증가시키는 반면, fructose는 수축력을 증가시키지 못했다. 이 결과는 citrate와 bicarbonate-free medium이 Embden-Meyerhof pathway의 일부, 즉 PFK step을 억제함을 시사한다. 외인성 기질이 없을때 citrate와 bicarbonate-free medium은 기질 제거 용액에서 심방 수축력을 현저히 감소시키며, acetate에 의해 수축력이 회복되었다. 이는 PFK step 이전 단계의 내인성 기질 (glycogen)이 citrated에 의해 억제됨을 시사한다. Lidocaine은 citrate에 의해 억제된 수축력을 더욱 감소시켰다. 이 결과는 lidocaine에 의한 심방 수축력 억제가 PFK step 이후 단계의 내인성 기질 억제에 의한 것임을 시사한다. 이상의 결과로 보아 lidocaine의 적출 심방에 대한 수축력 억제 작용은 두가지 (또는 그 이상)의 기전에 의한 것으로 사료된다: 하나는 PFK step 전단계의 해당과정의 억제기전이고 또 다른 기전은 PFK step 이후의 내인성 기질(들)의 억제인 것으로 사료된다.

• 대한약리학회지
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• 제29권1호
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• pp.57-63
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• 1993

심장에 작용하는 약물의 기전연구에 있어서 약물의 작용이 심근수축에 필요한 대사 기질과의 관계를 검토하고자, 심근 수축력 유지에 필요한 에너지원인 각종 대사기질의 정상쥐 적출 심방 수축력 유지능력과 굶긴 쥐 적출 심방의 수축력 유지 능력을 비교 관찰한 바 다음과 같은 실험결과를 얻었다. 1. 굶긴 쥐의 체중은 정상쥐에 비해 기아 (starvation) 시작 2일에서 약 15%의 체중감소를 나타냈다. 2. 정상 쥐의 적출 심방은 기질제거 용액에서 30분에 약 40%의 현저한 수축력의 감소를 보였다. 그러나 2일간 굶긴 쥐의 적출 심장은 기질제거액에서 30분에 약 13%의 수축력의 감소를 보여 정상 쥐에서의 수축력 저하보다 현저히 낮은 감소율을 나타냈다. 3. 기질제거 용액에서 glucose, pyruvate 및 acetate가 적출 심장의 수축력을 회복시키는 능력은 굶긴 쥐에서보다 정상쥐에서 현저히 높게 나타났다 4. 이상의 data들은 기질제거 용액에서 굻긴 쥐 적출 심장은 정상 쥐 적출 심장에 비해 현저히 적게 외인성 기질을 쓰고 있음을 시사하고 있다. 이상의 연구 결과로 미루어 보아 기아가 흰쥐의 현저한 체중감소를 초래하나, 심근의 수축성에 대해서는 유해하지 않은 것 같이 보여지며, 오히려 기아 기간 중 흰쥐의 적출 심장의 수축 기능에 필요한 내인성 대사 기질의 축적을 증가시킨다는 사실을 시사하고 있다.

• 한국동물학회지
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• 제37권1호
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• pp.130-136
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• 1994

Although alteration in protein phosphorylation by specific protein kinases is of importance in transducing cellular signals in a variety of neural/endocrine systems, little is known about protein phosphorylation in the hvpothalamus. The present study aims to explore whether activation of the second messenger-dependent protein kinases affects phosphorylation of specific proteins using a cell free phosphorylation system followed by SDS-polvacrylamide gel electrophoresis. Cytoplasmic fractions derived from hvpothalami of immature rats were used as substrates and several activators and/or inhibitors of CAMP-, phosphatidylinositol- and Ca2+-calmodulin-dependent protein kinases were assessed. Many endogenous proteins were extensively phosphorylated and depending on the signal transduction pathways, phosphorvlation profiles were markedly different. The present data indicate that extracellular signals may affect cellular events through protein phosphorylation by second messengers-protein kinases in the rat hypothalamus.

• Asian Pacific Journal of Cancer Prevention
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• 제14권12호
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• pp.7187-7191
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• 2013

Most of the exogenous and endogenous chemical compounds are metabolized by enzymes of xenobiotic processing pathways, including the phase I cytochrome p450 species. Carcinogens and their metabolites are generally detoxified by phase II enzymes like glutathione-S-transferases (GST). The balance of enzymes determines whether metabolic activation of pro-carcinogens or inactivation of carcinogens occurs. Under certain conditions, deregulated expression of xenobiotic enzymes may also convert endogenous substrates to metabolites that can facilitate DNA adduct formation and ultimately lead to cancer development. In this study, we aimed to test the association between deregulation of metabolizing genes and brain tumorigenesis. The expression profile of metabolizing genes CYP1A1 and GSTP1 was therefore studied in a cohort of 36 brain tumor patients and controls using Western blotting. In a second part of the study we analyzed protein expression of GSTs in the same study cohort by ELISA. CYP1A1 expression was found to be significantly high (p<0.001) in brain tumor as compared to the normal tissues, with ~4 fold (OR=4, 95%CI=0.43-37) increase in some cases. In contrast, the expression of GSTP1 was found to be significantly low in brain tumor tissues as compared to the controls (p<0.02). This down regulation was significantly higher (OR=0.05, 95%CI=0.006-0.51; p<0.007) in certain grades of lesions. Furthermore, GSTs levels were significantly down-regulated (p<0.014) in brain tumor patients compared to controls. Statistically significant decrease in GST levels was observed in the more advanced lesions (III-IV, p<0.005) as compared to the early tissue grades (I-II). Thus, altered expression of these xenobiotic metabolizing genes may be involved in brain tumor development in Pakistani population. Investigation of expression of these genes may provide information not only for the prediction of individual cancer risk but also for the prevention of cancer.

• 한국동물학회지
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• 제12권2호
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• pp.60-66
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• 1969

배추흰나비(Pieris rapae Linne)의 變態에 따른 hemolymph protein 의 濃度變化와 酸素消費量 및 5齡의 呼吸基質에 對한 活性度를 各各 Biuret method 와 Warburg manometric method 로 測定하여 形態的 變化를 比較하였다. 1. Hemolymph protein 의 濃度는 終齡幼蟲에서 가장 높으며 變態에 따라 감소하여 용기말에서 다시 增加한다. 2. Endogenous respiration은 전용기에서 가장 높은 酸素消費量을 보이며 變態에 따라 감소하여 용기말에서 다시 增加한다. 3. Glucose 는 全變態期를 通하여 다른 呼吸期質보다도 가장 큰 活性을 보이며 전용과 용기말에서 현저하게 영향을 미친다. 4. Hemolymph protein 의 濃度變化와 酸素消費量은 全變態期를 通하여 밀접한 연관을 가지며 幼蟲器官의 解消와 成蟲器官의 新生에 따라 U字型을 나타낸다.

• Journal of Acupuncture Research
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• 제20권5호
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• pp.172-186
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• 2003

Acupuncture therapy has demonstrated efficacy in several clinical areas, and of these areas the understanding of pain has progressed immensely in the last two decades. The underlying mechanisms of acupuncture in general and the analgesic effect in particular are still not clearly delineated. The leading hypothesis include the effects of local stimulation, neuronal gating, release of endogenous opiates, and the placebo effect. Accumulating evidence suggests that the central nervous system(CNS) is essential for the processing of these effects, via its modulation of the autonomic nervous system, neuro-immune system, and hormonal regulation. These processes tap into basic survival mechanisms. As such, understanding the effects of acupuncture within a neuroscience-based framework becomes vital. We propose a model which incorporates the stress-induced hypothalamus-pituitary-adrenal axis(HPA-axis) model of Akil et al., the cholinergic anti-inflamatory observations of Tracey et al., and Petrovic et al.

• BMB Reports
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• 제29권6호
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• pp.500-506
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• 1996

We have isolated a water-extracted novel regulator for blood coagulation from an earthworm, Lumbricus rubellus. As a folk remedy, the earthworm has been known to facilitate blood circulation. After complete heat inactivation of endogenous proteases in the earthworm, an anticoagulant(s) was purified through ammonium sulfate fractionation and three consecutive gel permeation chromatography of Sephacryl S-300, Sephadex G-75, and G-150 by measuring activated partial thromboplastin time (APTT) The anticoagulant was further purified to 2,800 fold with a C4 reversed-phase HPLC This activity was stable under heat ($100^{\circ}C$ for 30 min) and acidic conditions (0.4 N HCl). The effects of this partially purified anticoagulant on thrombin were observed with various substrates such as N${\alpha}$-benzoyl-DL-arginine-p-nitroanilide (BApNA), H-D-phenylalanyl-L-pipecoyl-L-arginine-p-nitroanilide (S-2238), N${\alpha}$-p-tosyl-L-arginine methyl ester (TAME), and fibrinogen as a natural substrate. Only TAME hydrolysis, due to an esterase activity of the enzyme, was inhibited among the chromogenic substrates. In addition, the anticoagulant not only inhibited the conversion of fibrinogen to fibrin but also prolonged the fibrin clot formation monitored with the in vitro coagulation test. Based on these observations, we suggest the significance of measuring the ability of antithrombotic drugs to inhibit the esterase activity of thrombin. In this report, it was also shown that the earthworm indeed contained a water-extractable, heat- and acid-stable anticoagulant which could be used as a novel antithrombotic agent.