• The Korean Journal of Physiology
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• 제30권2호
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• pp.279-288
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• 1996

Chronic exposure to cadmium impairs various renal tubular functions, including organic acid (anion) secretion. To investigate the mechanism of cadmium-induced alterations in the organic anion transport system, kinetics of p-aminohippurate (PAH) uptake was studied in renal cortical basolateral membrane vesicles (BLMV) isolated from cadmium-intoxicated rats (adult male Sprague-Dawley). Cadmium intoxication was induced by subcutaneous injections of $CdCl_{2}$ (2 mg Cd/kg per day) for 3 weeks. The renal plasma membrane vesicles were prepared by Percoll gradient centrifugation. The vesicular uptake of $^{14}C$-PAH was determined by rapid filtration technique using Millipore filter. Cadmium intoxication resulted in a marked attenuation of $Na^{+}$-dependent, ${\alpha}$-ketoglutarate (${\alpha}$KG)-driven PAH uptake with no changes in $Na^{+}$ and ${\alpha}$KG-independent transport component. Kinetic analysis indicated that Vmax, but not Km, of the $Na^{+}$-dependent, ${\alpha}$KG-driven component was reduced. A similar reduction of $Na^{+}$-dependent, ${\alpha}$KG-driven PAH uptake was observed in normal membrane vesicles directly exposed to inorganic cadmium in vitro, and this was accompanied by an inhibition of both $Na^{+}$-dependent ${\alpha}$KG uptake and ${\alpha}$KG-PAH exchange activity. These results indicate that during chronic exposure to cadmium, free cadmium ions liberated in the proximal tubular cytoplasm directly interact with the basolateral membrane and impair the active transport capacity for organic anions, most likely due to an inhibition of both $Na^{+}$-dicarboxylate cotransporter and dicarboxylate-organic anion antiporter activities.

• The Korean Journal of Physiology
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• 제30권2호
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• pp.249-256
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• 1996

The effect of probenecid on the transport of tetraethylammonium (TEA) was studied in renal cortical slices and isolated membrane vesicles to investigate the interaction of organic anion with the organic cation transport system in proximal tubule. Probenecid reversibly inhibited TEA uptake by renal cortical slices in a dose-dependent manner over the concentration range of 1 and 5 mM. The efflux of TEA was not affected by the presence of 3 mM probenecid. Kinetic analysis indicated that probenecid decreased Vmax without significant change in Km. Probenecid inhibited significantly tissue oxygen consumption at concentrations of 3 and 5 mM. However, probenecid did not significantly reduce TEA uptake in brush border and basolateral membrane vesicles prepared from renal cortex even at a concentration as high as 10 mM. These results indicate that probenecid reduces TEA uptake in cortical slices by inhibiting tissue metabolism rather than by an interaction with the organic ration transporter.

• The Korean Journal of Physiology
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• 제21권2호
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• pp.283-289
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• 1987

Uric acid transport across the basolateral membrane of renal proximal tubules was studied in rabbit kidney cortical slices. Uric acid uptake was greater under $O_2$ atmosphere compared to under $N_2$ atmosphere, and was increased with $Na^{2+}$ concentration in incubation medium. Uric acid inhibited PAH uptake but not TEA uptake and did trans-stimulated PAH efflux. PAH also inhibited uric acid uptake. Uric acid uptake was inhibited by harmaline, ouabin, SITS, DIDS and pyrazinoic acid. The inhibition of PAH uptake by these inhibitors also was reasonably comparable to that of uric acid uptake. These results suggest that uric acid was transported across the basolateral membrane of renal tubule by a carrier-mediated process which was by a common transport system with PAH in rabbit.

• The Korean Journal of Physiology
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• 제22권2호
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• pp.307-318
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• 1988

가토 신장 피질에서 Percoll density gradient방법으로 분리한 basolateral membrane vesicle (BLMV)에서 rapid filtration technique을 이용하여 succinate의 이동 특성을 관찰하였다. $Na^+$은 succinate의 이동을 증가시켜 "overshoot"현상을 보였으며 이러한 효과는 $K^+,{\;}Li^+,{\;}Rb^+,{\;}choline$과 같은 다른 양이온들에 의해 나타나지 않았다. $Na^+$농도변화에 따른 succinate의 이동율은 sigmoid모양을 보였고, $Na^+$에 대한 Hill coefficient는 2.0이었다. soccinate의 이동은 vesicle 내부가 음전압일 때 더욱 증가되었다. BLMV에서 succinate이동은 용액내 pH변화에 따라 영향을 받았으나 brush border membrane vesicle (BBMV)에서는 영향을 받지 않았다. 동력학적 분석결과 succinate의 Km값은 $15.5{\pm}0.94{\;}{\mu}M$이었고 Vmax는 $16.22{\pm}0.25{\;}n{\;}mole/mg{\;}protein/min$이었다. succinate의 이동은 $4{\sim}5$탄소를 가진 dicarboxylate들에 의해 강력하게 억제되었으나 monocarboxylate나 다른 유기음이온들에 의해 영향을 적게 받거나 받지 않았다. succinate의 이동은 DIDS, SITS, furosemide와 같은 음이온 이동 억제제와 harmaline과 같은 $Na^+$ 이동 억제제에 의해 억제되었다. 이들 결과들은 BLMV에서 succinate는 $Na^+$에 의존하여 이동하며 다른 Krebs cycle중간 산물들과 동일한 운반기전을 이용함을 가르킨다. 또한 BLMV에서 succinate의 이동은 그 기질특이성에 있어서 다른 연구자에 의해 보고된 BBMV에서 이동특성과 유사함을 보였다.

• 한국염색가공학회지
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• 제21권1호
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• pp.1-9
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• 2009

A lot of research has been made over the recent decade to develop testing packages with antimicrobial properties to improve food safety. In this study, a new method, experimental device and technology for environmental corresponding packages of polypropylene (PP) film has been developed to provide effective temperature buffering during the transport/long-term storage of grains or foodstuffs from the supplier to the market. This quantitatively optimized mixing system enabled to produce PP films with the 700$\sim$1,400d (width;1.5$\sim$3mm, thickness;0.01$\sim$0.5mm). In the whole mixing systems, the finely-granulated inorganic illite and PP virgin chip for master batch (M/B) chip was calculated by digital measurement methods, and then the M/B chip for PP film was adapted through a air jet and PP grinding method. The prepared PP film was characterized with tensile strength and elongation, far infrared radiation (FIR) emissivity, antimicrobial activity and deodorization properties. The results revealed that the two differently grain-sized illite could be show homogeneously dispersed on PP chip surface, and as the increasing of illite content, the FIR emissivity and the anion emission rate of film was increasingly improved. In both of 325 and 1,500 mesh-sized illite contained PP chip, of course the antimicrobial activity was good. But the ultimate deodorization rate for ammonia gas of PP film were found to be approximately the same.