• Asian-Australasian Journal of Animal Sciences
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• v.3 no.2
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• pp.91-96
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• 1990

This experiment was designed to determine whether ${\alpha}$-aminoisobutyric acid (AIB) can be used to predict membrane function of spermatozoa by measuring the uptake of AIB by fresh, stored and frozen-thawed rooster spermatozoa. When spermatozoa were stored at low temperature ($0{\sim}3^{\circ}C$) for 24 h. no difference was found in AIB uptake compared with fresh spermatozoa, whereas storage for 48 h resulted in a slight increase in AIB uptake by spermatozoa. On the one hand, the uptake of AIB by frozen-thawed spermatozoa was less than that by fresh spermatozoa. This suggests possibility of a different membrane transport system between spermatozoa preserved at low temperature ($0{\sim}3^{\circ}C$) and those frozen-thawed. Glycerol used as cryoprotectant may modify rooster sperm membrane in a different manner from cold preservation. Ouabaine ($10^{-4}M$) caused a slight decrease in AIB uptake, but caffeine ($10^{-2}M$) did not influence spermatozoal AIB uptake. These results indicate a successful application of AIB to rooster spermatozoa as a mean for measuring sperm membrane function and suggest a possible alteration of membrane transport system in rooster spermatozoa between cold ($0{\sim}3^{\circ}C$) and cryopreservation ($-196^{\circ}C$).

• Toxicological Research
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• v.3 no.2
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• pp.73-80
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• 1987

Primary cultures of adult rat hepatocytes were used to study the cytotoxicity of D-galactosamine. Hepatocytes were isolated by a collagenase perfusion technique and maintained as monolayers in serum-free medium on collagen-coated culture dishes. Treatment of galactosamine to the culture markedly inhibited the uptake of ${\alpha}$-aminoisobutyric acid (AIB) inducible with glucagon and dexamethasone. At0.1 mM of galactosamine, AIB uptake was inhibited significantly when treated for 12 hr. At higher doses (0.25, 0.5 and 1.0mM), a significant inhibition was noticed after 1 hr exposure. Generally the magnitude of the inhibition was related to the dose and treatment time of galactosamine. Treatment of galactosamine also produced a dose- and treatment time-related suppression of the tyrosine aminotransferase (TAT) induction caused by dexamethasone. Meanwhile, uptake of ouabain was not affected by the treatment of galactosamine. The viability of the hepatocytes was decreased only slightly by the treatment of galactosamine; more than 87% of the cells excluded tryphane blue when treated 1 mM galactosamine for 12 hr. Galactosamine induced depressions of AIB uptake and TAT activity were prevented by the simultaneous addition of uridine to the culture. D-Galactosamine, cytotoxicity, hepatocytes culture, ${\alpha}$-aminoisobutyric acid uptake, tyrosine aminotransferase.

• Korean Journal of Veterinary Research
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• v.37 no.1
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• pp.111-117
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• 1997

This study was carried out determine the effect of renal ischemia on amino acid transport in rabbit renal cortical slices. The animal models of renal ischemia induced experimentally by clamping the renal artery. These results were summarized as follows: 1. The uptake of amino acids lysine and ${\alpha}$-aminobutyrate(AIB), dicarboxylate succinate and organic anion PAH in cortical slices was normal or increased after 30 or 60 min of ischemia in vivo. 2. In a 30 min ischemic kidney, the slice uptake of amino acids was returned to the control level by 30 min of reflow. In a 60 or 90 min ischemic kidney, the lysine uptake was returned to the control level after of reflow, but the uptake of AIB and succinate was significantly reduced during reflow period of 30-120 min. 3. Oxygen consumption in cortical slices was increased after 30 min of ischemia but was not altered by 60 min of ischemia. This results indicat that transient ischemia caused increasing of amino acid uptake in renal cortical slices without metabolic disorder of renal proximal tubule.

• Toxicological Research
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• v.4 no.1
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• pp.37-45
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• 1988

Primary cultures of adult rat hepatocytes were used to study in vitro cytotoxic effects of T-2 toxin on liver cells. When T-2 toxin was added to the culture, a significant depression of the hormonal induction of ${\alpha}$-aminoisobutyric acid (AIB) uptake and tyrosine aminotransferase (TAT) activity was observed. However, T-2 toxin did not affect the uptake of ouabain into hepatocytes. Protein synthesis was inhibited by T-2 toxin, but RNA synthesis was not severely affected. The inhibitory effects of T-2 toxin on protein synthesis was diminished rapidly with culture time and the hepatocytes culture maintained control level of protein synthesis within 24 hrs.

• The Korean Journal of Physiology and Pharmacology
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• v.3 no.5
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• pp.529-538
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• 1999

This study was undertaken to examine the effect of ethanol on $Na^+ -dependent$ phosphate $(Na^+-P_i)$ uptake in opossum kidney (OK) cells, an established renal proximal tubular cell line. Ethanol inhibited ^Na^+-dependent$ component of phosphate uptake in a dose-dependent manner with $I_{50}$ of 8.4%, but it did not affect $Na^+-independent$ component. Similarly, ethanol inhibited $Na^+-dependent$ uptakes of glucose and amino acids (AIB, glycine, alanine, and leucine). Microsomal $Na^+-K^+-ATPase$ activity was not significantly altered when cells were treated with 8% ethanol. Kinetic analysis showed that ethanol increased $K_m$ without a change in $V_{max}$ of $Na^+-P_i$ uptake. Inhibitory effect of n-alcohols on $Na^+-P_i$ uptake was dependent on the length of the hydrocarbon chain, and it resulted from the binding of one molecule of alcohol, as indicated by the Hill coefficient (n) of 0.8-1.04. Catalase significantly prevented the inhibition, but superoxide dismutase and hydroxyl radical scavengers did not alter the ethanol effect. A potent antioxidant DPPD and iron chelators did not prevent the inhibition. Pyrazole, an inhibitor of alcohol dehydrogenase, did not attenuate ethanol-induced inhibition of $Na^+-P_i$ uptake, but it prevented ethanol-induced cell death. These results suggest that ethanol may inhibit $Na^+-P_i$ uptake through a direct action on the carrier protein, although the transport system is affected by alterations in the lipid environment of the membrane.

• Toxicological Research
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• v.8 no.2
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• pp.285-302
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• 1992

Human and rat hepatocytes were isolated by nonperfusion method and cultured for longer than 5 days. Human liver biopsy sample and rat liver were used as hepatocyte source. Several physical and chemical factors which were influencing on hepatocyte isolation procedure were examined and a batch isolation procedure was established for small size sample of rat liver. Isolated hepatocytes showed normal morphlologica characteristics in microscopy and electron microscopical examinations and a morphologica response to phalloidin. Isolated cells were cultured as a monolayer and proven to have intact morphological characteristics for longer than 15 days. Because human liver sample is harder and tighter compared with rat liver, a standard procedure for rat hepatocytes was slightly modified to reduce mechanical damage. Similarly with rat hepatocytes, isolated human hepatocytes showed a normal morphological characteristics and could be cultured for longer than 15days. Human and rat hepatocytes were examined on their functional integrities including cytochrome-P450 related enzyme activity and it's inducibility, hormonal inducibility of AIB uptake and TAT activity, albumin synthesis, DNA synthesis, cellular protein maintenance. In all parameters used in the present study, human and rat hepatocytes showed normal functional characteristics.