• Asian-Australasian Journal of Animal Sciences
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• v.26 no.6
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• pp.874-878
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• 2013

Unlike Europe (particularly, Italy and Spain), where a number of studies have been conducted on the stressful effects of transport on rabbit welfare, few studies have been conducted on transportation of rabbits under hot, humid tropical conditions experienced in countries like Malaysia. We studied the effects of transportation in hot humid tropical conditions of Malaysia on physiometabolic changes in New Zealand white rabbits. Eighty experimental animals were divided into two groups of 40 bucks each and transported for either 3 or 1 h. Transportation caused a significant upsurge of aspartate aminotransferase, alanine aminotransferase and creatine kinase activities (p<0.001) though did not significantly affect lactate dehydrogenase (LDH) activity (p = 0.0706). Both transportation periods caused elevation in plasma glucose levels, lactic acidosis and dehydration as evidenced through elevated packed cell volume and plasma protein concentration. It was concluded that regardless of the duration, transport of rabbits under hot humid tropical conditions, resulted in heat distress since the rabbits showed hyperglycemia, hypercalcemia, lactacidemia, lymphocytopenia, dehydration and increase in blood enzyme activities.

• Journal of Pharmaceutical Investigation
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• v.29 no.1
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• pp.13-19
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• 1999

Canalicular liver plasma membrane vesicles (cLPM) were prepared according to two different methods (Inoue method and Meier method), and were evaluated for their protein yield, enzyme activity and transport characteristics. No difference was found between the methods in the protein yield (i.e., $0.14{\pm}0.031$ and $0.15{\pm}0.050$ mglg liver for Inoue method and Meier method, respectively). The activity of alkaline phosphatase, a marker enzyme of canalicular membrane, was significantly (P<0.05) higher in the vesicles of Meier method $(3.52{\pm}0.91\;mmol/mg/hr)$than in the vesicles of Inoue method ($2.28{\pm}0.94$ mmol/mg/hr) indicating that more purified cLPM were obtained from Meier method compared with Inoue method. ATP-dependent vesicular uptake of taurocholate and tributylmethylammonium (TBuMA) was observed for vesicles of both methods, and the kinetic parameters responsible for the transport were similar between the vesicles of both methods (for example, $V_{max}:$ 9.72 nmol/mg protein/30sec and $K_m:$ 0.63 mM for Inoue method; $V_{max}:$ 10.1 nmol/mg protein/30sec and $K_m:$ 0.70 mM for Meier method). A pH gradient dependent counter transport of TBuMA was also observed for both vesicles with similar kinetic characteristics. Either the uptake of taurocholate in the absence of ATP or that of TBuMA in the absence of pH gradient, which may represent passive diffusion of respective compound into the vesicles, was more rapid for the vesicles of Meier method than for the vesicles of Inoue method. For example, passive diffusion rate constants $(K_d)$ for TBuMA uptake into the vesicles were 0.00030 and 0.00052\;{\mu}l/mg$ protein/min for the vesicles of Inoue method and Meier method, respectively. It may indicate that more leaky vesicles are obtained form the Meier method compared with the Inoue method. These aspects together with the time necessary to prepare the vesicles (i.e., 8 hr for Inoue method and 23 hr for Meier method) should be considered before selecting an appropriate method for the preparation of cLPM.

• Microbiology and Biotechnology Letters
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• v.13 no.2
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• pp.119-127
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• 1985

A series of Escherichia coli mutants were exmined for ability to convert glucose and ammonium salts into phenylalanine. This enabled the biochemical changes having major. effects on phenylaianine yield, and interactions between mutations, to be identified. Changes to the common pathway of aromatic biosynthesis having a major effects include desensitization of the first enzyme (3-deoxy-D-arabinoheptulosonate synthase) to end-product inhibition, and removal of repression of enzyme synthesis. It is suggested that the 3-deoxy-D-arabino-heptulosonate synthase Phe isoenzyme has a more important effect on yield. Similarly, removal of repression and end-product inhibition on the phenylalanine terminal pathway increased yield, and changes to both common and branch pathways were synergistic. Blockage of the typrosine and tryptophan pathways had minor effects on phenylalanine yield, and a mutation affecting aramatic amino acid transport (aroP) decreased yield. With multiple-mutation strains hish specific rates of product formation (ie 0.1-0.17g phenylalanine/g cells/h) were obtained.

• Journal of Pharmaceutical Investigation
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• v.28 no.1
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• pp.25-33
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• 1998

Intestinal absorption of ${\beta}-lactam$ antibiotics and angiotensin converting enzyme(ACE) inhibitors has been shown to use the carrier-mediated transport system. In vitro experiments have established that the efficacy of uptake by enterocytes depends on an inwardly directed proton gradient. It was suggested that benazepril was mediated by tripeptide transport system and that amoxicillin was transported by dipeptide transport carrier. The aim of this study is to assess the influence of amoxicillin on the intestinal absorption of benazepril using in vitro diffusion chamber and in situ single pass perfusion technique in the rat in order to elucidate whether the above transport systems are competitive or not. We obtained the gastrointestinal pemeability coefficient of amoxicillin, benazepril and both of them using in vitro diffusion chamber. And also the gastrointestinal absorption clearance of amoxicillin, benazepril and both of them using in situ single-pass perfusion method at steady state were calculated. Amoxicillin and benazepril were analyzed by HPLC. The results by the use of diffusion chamber in vitro indicated that the apparent intestinal permeability coefficient of benazepril was significantly(p<0.01) decreased by amoxicillin(45.2%) and vice versa significantly(p<0.01) decreased(89.1%). The results by the in situ gastrointestinal single-pass perfusion method indicated that the intestinal absorption clearance of benazepril was significantly(p<0.05) decreased by amoxicillin (40.2%) and vice versa significantly(p<0.05) decreased(54.8%). These results might suggest that they share the same peptide carrier pathway for oral absorption.

• Animal Bioscience
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• v.34 no.5
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• pp.880-885
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• 2021

Objective: Omasum is an important site for the absorption of short chain fatty acids. The major route for the transport of acetate is via sodium hydrogen exchanger (NHE). However, a discrepancy in the symmetry of sodium and acetate transport has been previously reported, the mechanism of which is unclear. In this study, we investigated the possible role of carbonic anhydrase (CA) for this asymmetry. Methods: Omasal tissues were isolated from healthy sheep (N = 3) and divided into four groups; pH 7.4 and 6.4 alone and in combination with Ethoxzolamide. Electrophysiological measurements were made using Ussing chamber and the electrical measurements were made using computer controlled voltage clamp apparatus. Effect(s) of CA inhibitor on acetate and sodium transport flux rate of Na22 and 14C-acetate was measured in three different flux time periods. Data were presented as mean±standard deviation and level of significance was ascertained at p≤0.05. Results: Mucosal to serosal flux of Na (JmsNa) was greater than mucosal to serosal flux of acetate (JmsAc) when the pH was decreased from 7.4 to 6.4. However, the addition of CA inhibitor almost completely abolished this discrepancy (JmsNa ≈ JmsAc). Conclusion: The results of the present study suggest that the additional protons required to drive the NHE were provided by the CA enzyme in the isolated omasal epithelium. The findings of this study also suggest that the functions of CA may be exploited for better absorption in omasum.

• The Journal of Internal Korean Medicine
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• v.11 no.2
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• pp.148-169
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• 1990

The Present experiment was designed to investigate the effects of Soo Jeom San on the function of heart and digestive organs. And thus it was analyzed the total acidity, recovery effect, and the other various enzyme activities such as ATPase, Creatine kinase, Aspartate transaminase, and Lactate dehydrogenase. The results were obtained as follows : 1. The Total acidity decreased after Soo JeomSan administration for 6 days, however the total acidity inoreased after the drug administration for 9 days, these phenomena demonstrate that Soo Jeom San acts as a dual factor. The mechanism of decreasing the total acidity was considered to the inhibition of ATPase activity used for HCI active transport from parietal cells. 2. Soo Jeom San recovered the islets of Langerhans which was disrupted by streptozotocin. The recovery mechanism was suggested that Soo Jeom San stimulates the ${\beta}-cell$ proliferation. 3. Soo Jeom San inhibited the enzyme activities such as Creatine kinase and Aspartate transaminase, however the drug activated Lactate dehydrogenase. According to the obtained results, Soo Jeom San may be used for curing gastric ulcer and myocardiac infarction.

• Archives of Pharmacal Research
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• v.26 no.11
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• pp.951-959
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• 2003

A series of typical (chlorpromazine, haloperidol and thioridazine) and atypical (risperidone, quetiapine, clozapine and olanzapine) antipsychotics were tested for effects on integrated bioenergetic functions of isolated rat liver mitochondria. Polarographic measurement of oxygen consumption in freshly isolated mitochondria showed that electron transfer activity at respiratory complex I is inhibited by chlorpromazine, haloperidol, risperidone, and quetiapine, but not by clozapine, olanzapine, or thioridazine. Chlorpromazine and thioridazine act as modest uncouplers of oxidative phosphorylation. The typical neuroleptics inhibited NADH-coenzyme Q reductase in freeze-thawed mitochondria, which is a direct measure of complex I enzyme activity. The inhibition of NADH-coenzyme Q reductase activity by the atypicals risperidone and quetiapine was 2-4 fold less than that for the typical neuroleptics. Clozapine and olanzapine had only slight effects on NADH-coenzyme Q reductase activity, even at 200 $\mu$ M. The relative potencies of these neuroleptic drugs as inhibitors of mitochondrial bioenergetic function is similar to their relative potencies as risk factors in the reported incidence of extrapyramidal symptoms, including tardive dyskinesia (TD). This suggests that compromised bioenergetic function may be involved in the cellular pathology underlying TD.

• Journal of Microbiology and Biotechnology
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• v.23 no.4
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• pp.467-472
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• 2013

Helicobacter pylori increased the ${\gamma}$-glutamyltranspeptidase (GGT) production under low-pH (maximal at pH 4) and appropriate $pCO_2$ conditions, while the production of GGT mRNA correlated with increased total enzyme activity. At pH 4, the bacterium augmented enzyme production in the presence of glutamine (~10 mM) in the medium, which predominantly occurred after a 6-min time-lag. Monovalent salts such as NaCl or $NH_4Cl$ facilitated enzymatic activation in acidic solutions of approximately pH 4.5. In addition, glutathione's ${\gamma}$-glutamyl moiety cysteinylglycine appeared to be taken up readily by the intact H. pylori, but not by the one pretreated with a potent GGT inhibitor, acivicin, suggesting that the GGT may partake in glutathione uptake by the cell.

• Biomolecules & Therapeutics
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• v.20 no.3
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• pp.245-255
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• 2012

Amyloid-${\beta}$ peptide ($A{\beta}$) is still best known as a molecule to cause Alzheimer's disease (AD) through accumulation and deposition within the frontal cortex and hippocampus in the brain. Thus, strategies on developing AD drugs have been focused on the reduction of $A{\beta}$ in the brain. Since accumulation of $A{\beta}$ depends on the rate of its synthesis and clearance, the metabolic pathway of $A{\beta}$ in the brain and the whole body should be carefully explored for AD research. Although the synthetic pathway of $A{\beta}$ is equally important, we summarize primarily the clearance pathway in this paper because the former has been extensively reviewed in previous studies. The clearance of $A{\beta}$ from the brain is accomplished by several mechanisms which include non-enzymatic and enzymatic pathways. Nonenzymatic pathway includes interstitial fluid drainage, uptake by microglial phagocytosis, and transport across the blood vessel walls into the circulation. Multiple $A{\beta}$-degrading enzymes (ADE) implicated in the clearance process have been identified, which include neprilysin, insulin-degrading enzyme, matrix metalloproteinase-9, glutamate carboxypeptidase II and others. A series of studies on $A{\beta}$ clearance mechanism provide new insight into the pathogenesis of AD at the molecular level and suggest a new target for the development of novel therapeutics.

• The Korean Journal of Physiology
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• v.29 no.2
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• pp.191-202
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• 1995

The purpose of this study was to compare effects of insulin and IGFs on growth, apical membrane enzyme activities and membrane transport systems of primary cultured rabbit kidney proximal tubule cells. Results were as follows: 1. Insulin and IGF-I produced significant growth stimulatory effects at $5{\times}10^{-10}M.\;IGF-II(5×10^{-10}\;M)$ did not stimulate significant cell growth. 2. Insulin stimulated the phosphorylation of a 97 KD protein. It was difficult to determine whether this band represents insulin and/or the IGF-I receptor. 3. The activities of apical membrane enzymes (alkaline phosphatase, leucine aminopeptidase, and ${\gamma}-glutamyl \;transpeptidase)$ were observed to be diminished after the cells were placed in the culture environment. 4. The uptake of ${\alpha}-MG,$ Pi and Na was significantly increased in cells incubated with insulin or IGF-I, IGF-II had no effect on the uptake of these substrates. 5. Na-pump activity, as assayed by Rb uptake, was significantly increased in cells treated with insulin or IGFs. In conclusion, insulin and IGF-I exert stimulatory effects on growth and membrane transporter(glucose, Na, Pi, and Na-pump) activities in primary cultured rabbit kidney proximal tubule cells. IGF-II had no effect on cell growth and membrane transporter(glucose, Na and Pi) activities.