• The Korean Journal of Physiology
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• v.27 no.2
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• pp.227-232
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• 1993

The temperature dependence of $Na^+-dependent$ succinate uptake was studied in brush border (BBMV) and basolateral (BLMV) membrane vesicles isolated from the rabbit kidney cortex. The succinate uptake was markedly altered by temperature in a similar fashion in both membranes. The temperature dependence was characterized by a nonlinear Arrhenius plot with a break point at 22 and $25^{\circ}C$ for BBMV and BLMV, respectively. The activation energy was 3.91 and 17.09 kcal/mole at above and below the break point respectively, far BBMV; 2.65 and 14.05 kcal/mole, respectively, for BLMV. When temperature increased f개m 20 to $35^{\circ}C$, the Vmax of succinate transport increased from $3.49{\pm}0.11\;to\;5.90{\pm}0.86\;nmole/mg/5\;sec$ for BBMV and from $2.86{\pm}0.25\;to\;3.63{\pm}0.32\;nmole/mg/5\;sec$ for BLMV, with no change in Km in both membranes. These results suggest that renal dicarboxylate transport is similarly sensitive to a change in membrane physical state in BBMV and BLMV.

• The Korean Journal of Physiology
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• v.22 no.2
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• pp.307-318
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• 1988

Properties of succinate transport were examined in basolaterat membrane vesicles (BLMV) isolated from rabbit renal cortex. An inwardly directed $Na^+$ gradient stimulated succinate uptake and led to a transient overshoot. $K^+,{\;}Li^+,{\;}Rb^+$ and choline could not substitute for $Na^+$ in the uptake process. The dependence of the initial uptake rate of succinate on $Na^+$ concentration exhibited sigmoidal kinetics, indicating interaction of more than one $Na^+$ with transporter Hill coefficient for $Na^+$ was calculated to be 2.0. The $Na^+-dependent$ succinate uptake was electrogenic, resulting in the transfer of positive charge across the membrane. The succinate uptake into BLMV showed a pH optimum at external pH $7.5{\sim}8.0$, whereas succinate uptake into brush border membrane vesicles (BBMV) did not depend on external pH. Kinetic analysis showed that a Na-dependent succinate uptake in BLMV occurred via a single transport system, with an apparent Km of $15.5{\pm}0.94{\;}{\mu}M$ and Vmax of $16.22{\pm}0.25{\;}nmole/mg{\;}protein/min$. Succinate uptake was strongly inhibited by $4{\sim}5$ carbon dicarboxylates, whereas monocarboxylates and other organic anions showed a little or no effect. The succinate transport system preferred dicarboxylates in trans-configuration (furmarate) over cis-dicarboxylates (maleate). Succinate uptake was inhibited by the anion transport inhibitors DIDS, SITS and furosemide, and $Na^+-coupled$ transport inhibitor harmaline. These results indicate the existence of a $Na^+-dependent$ succinate transport system in BLMV that may be shared by the other Krebs cycle intemediates. This transport system seems to be very similar to the luminal transport system for dicarboxylates.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.2
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• pp.246-253
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• 2009

This study was conducted to investigate the effects of Chinese medicine granule (CMG, including Cortex Phellodendron, Atractylodes Rhizome, Agastache Rugosa and Gypsum Fibrosum) on absorption and transport of glucose in porcine small intestinal brush border membrane vesicles (BBMVs) under heat stress. Forty-eight 2-month-old Chinese experimental barrows were screened according to weight and litter origin, and then allotted to three groups and treated as follows: Normal temperature control group (NTCG; $23^{\circ}C$), high temperature control group (HTCG; $26^{\circ}C$ for 19 h, $40^{\circ}C$ for 5 h); Chinese medicine granule anti-stress group (CMGG; $26^{\circ}C$ for 19 h, $40^{\circ}C$ for 5 h) (n = 16 per group). The results showed that high temperature treatment decreased (p<0.05) the growth performance and intestinal glucose absorption but there was no change (p>0.05) in the expression of SGLT1 and GLUT2 genes in the small intestine of pigs compared with the NTCG. Dietary supplementation with CMG improved the growth performance, and increased the activity of disaccharidases in duodenum and jejunum of heat stressed pigs (p<0.05). CMG treatment increased (p<0.05) the protein levels of SGLT1 and GLUT2 in the small intestine, and up-regulated (p<0.05) the expression of SGLT1 and GLUT2 genes in the duodenum and jejunum but without changing (p>0.05) them in the ileum compared with the HTCG. These results indicated that CMG treatment significantly improved porcine growth performance, and increased intestinal glucose absorption and transport by BBMVs under heat stress, in addition to up-regulating the expression of SGLT1 and GLUT2 genes in porcine duodenum and jejunum.

• Applied Microscopy
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• v.17 no.2
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• pp.23-30
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• 1987

There are groups of large monopolar cells containing numerous secretory inclusions in the muscular and connective tissue. These cells contain the electron-lucent vesicles in the size of $0.5{\sim}0.9{\mu}m$, which are secreted to the exterior of the tentacle through their cytoplasmic processes projected to the epithelial layer. Secretory material can be seen accumulating in swollen portions of the granular endoplasmic reticulum. It is postulated that this material is transported to the Golgi-complex and thus the limiting membrane of the inclusions is derived from the Golgi-membrane. An electron lucent material secreted from these cells seems to be similar to fibrous electron lucent material filled in the brush border of the epidermis.

• The Korean Journal of Physiology
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• v.25 no.1
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• pp.49-60
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• 1991

The change of the acridine orange absorbance was used to monitor the formation and/or dissipation of a pH gradient in microvillous membrane vesicles (MVV) isolated from human term placenta. Under $Na^+$ efflux conditions, an acidification of the intravesicular space occured and it was completely inhibited by 0.1 mM amiloride. Under $K^+$ efflux conditions, an acidification of the intravesicular space occured and it was potentiated by valinomycin or FCCP. An inwardly directed chloride gradient also induced a minor intravesicular acidification, but it was not observed in voltage-clampled MVV. The initial rate of the dissipation of a pH gradient was accelerated by pulse injections of $Na^+$ in a saturable manner and $Li^+$ could replace $Na^+$. The kinetic parameter of $Na^+$ in placental $Na^+/H^+$ exchange was similar to that of renal $Na^+/H^+$ exchange. Amiloride was a inhibitor of directly coupled $Na^+/H^+$ exchange and its $IC_{50}$ in placental MVV was about 14-fold higher than that in renal brush border membrane. These results indicate that $Na^+/H^+$ exchanger exists in human placental MVV and that its kinetic characteristics is similar to that of renal $Na^+/H^+$ exchanger but its pharmacological characteristics is different. In placental MVV $K^+,\;H^+$, and, relatively minor chloride conductances are present. The magnitude of $Cl^-/OH^-$ exchange, even though it exists, seems to be smaller than that of $Na^+/H^+$ exchange.

• The Korean Journal of Physiology and Pharmacology
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• v.6 no.1
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• pp.41-46
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• 2002

Effect of cadmium (Cd) intoxication on renal acid-base regulation was studied in adult male Sprague-Dawley rats. Cd intoxication was induced by subcutaneous injections of $CdCl_2$ at a dose of 2 mg Cd/kg/day for $3{\sim}4$ weeks. In Cd-intoxicated animals, arterial pH, $PCO_2$ and plasma bicarbonate concentration decreased, showing a metabolic acidosis. Urine pH and urinary bicarbonate excretion increased and titratable acid excretion decreased with no change in ammonium excretion. In renal cortical brush-border membrane vesicles derived from Cd-exposed animals, the $Na^+/H^+$ antiporter activity was significantly attenuated. These results indicate that chronic exposures to Cd impair the proximal tubular mechanism for $H^+$ secretion (i.e., $Na^+/H^+$ antiport), leading to a metabolic acidosis.

• The Journal of Korean Medicine
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• v.21 no.3
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• pp.119-128
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• 2000

This study was carried out to determine if Salviae Radix extract (SRE) exerts protective effect against alterations in membrane transport function in rabbits with rhabdomyo lysis-induced acute renal failure. Acute renal failure was induced by intramuscular administration of glycerol (50%, 10 ml/kg). GFR in the glycerol-injected animals was reduced to 11% of the basal value and the fractional $Na^{+}$ excretion was increased to 7.8-fold, indicating generation of acute renal failure. When animals received SRE pretreatment for 7 days prior to glycerol injection, such changes were significantly attenuated. The fractional excretion of glucose and phosphate was increased more than 43-fold and 27-fold, respectively, in rabbits treated with glycerol alone. However, they were increased to 17-and 4.3-fold, respectively, in SRE-pretreated rabbits, and these values were significantly lower than those in rabbits treated with glycerol alone. Uptakes of glucose and phosphate in purified isolated brush-border membrane, the $Na^{+}-K^{+}-ATPase$ activity in microsomal fraction, and cellular ATP levels all were reduced in rabbits treated with glycerol alone. Such changes were prevented by SRE pretreatment. Uptakes of organic ions, PAH and TEA, in renal cortical slices were inhibited by the administration of glycerol, which was prevented by SRE pretreatment. Pretreatment of an antioxidant DPPD significantly attenuated the increase in the fractional excretion of glucose and phosphate induced by rhabdomyolysis. These results indicate that rhabdomyolysis causesimpairment inreabsorption of solutes in the proximal tubule via the generation of reactive oxygen species, and SRE pretreatment may provide the protection against the rhabdomyolysis-induced impairment by its antioxidant action.

• Archives of Pharmacal Research
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• v.29 no.7
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• pp.605-616
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• 2006

A wide variety of drugs and endogenous bioactive amines are organic cations (OCs). Approximately 40% of all conventional drugs on the market are OCs. Thus, the transport of xenobiotics or endogenous OCs in the body has been a subject of considerable interest, since the discovery and cloning of a family of OC transporters, referred to as organic cation transporter (OCTs), and a new subfamily of OCTs, OCTNs, leading to the functional characterization of these transporters in various systems including oocytes and some cell lines. Organic cation transporters are critical in drug absorption, targeting, and disposition of a drug. In this review, the recent advances in the characterization of organic cation transporters and their distribution in the small intestine are discussed. The results of the in vitro transport studies of various OCs in the small intestine using techniques such as isolated brush-border membrane vesicles, Ussing chamber systems and Caco-2 cells are discussed, and in vivo knock-out animal studies are summarized. Such information is essential for predicting pharmacokinetics and pharmacodynamics and in the design and development of new cationic drugs. An understanding of the mechanisms that control the intestinal transport of OCs will clearly aid achieving desirable clinical outcomes.

• The Korean Journal of Physiology
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• v.28 no.2
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• pp.203-214
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• 1994

Using the methods of stopped-flow and epifluorescence microscopy with entrapped fluorophore, membrane permeability of $NH_3$ and weak acids in liposomes, renal brush border (BBMV) and basolateral membrane vesicles (BLMV), and primary culture cells from renal proximal tubule was measured. Permeability coefficient (cm/sec) of $NH_3$ was $(2.9{\times}10^{-2}$ in phosphatidylcholine liposome $25^{\circ}C)$, $5.9{\times}10^{-2}$ in renal proximal tubule cell $(37^{\circ}C)$, $4.0{\times}10^{-2}\;and\;2.4{\times}10^{-2}$ in BBMV and BLMV $(25^{\circ}C)$, respectively. Formic acid has the highest permeability coefficient among the weak acids tested, which was $4.9{\times}10^{-3}$ in liposome, $5.0{\times}10^{-3}$ in renal proximal tubule cell, $9.1{\times}10^{-3}$ in BBMV and $3.8{\times}10^{-3}$ in BLMV. There was a linear relationship between external concentration of nonionized formic acid and initial rate of flux of formic acid in liposome, and the slope coincided with the value of permeability coefficient of formic acid measured in pH 7.0. These results show that techniques of stopped-flow and epifluorescence microscopy with entrapped fluorophore provide the precise method of measurement of very rapid transport of nonelectrolytes through membranes with the advantages of instantaneous mixing effect, good resolution time and easy manipulation.

• Journal of Acupuncture Research
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• v.15 no.2
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• pp.43-60
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• 1998

This study examined the histomorphomeric and histological changes of the left and right kidney in uninephrectomized rat. The results were as follows: 1. In the control, the right kidney was more prominent than the left in the basement membrane of glomerular capillaries. The podocyte had well developed Golgi apparatus in the left kidney and rough endoplasmic reticulum in the right kidney. 2. At the 30 days after unilateral nephrectomy, the basal lamina of glomerular capillaries was prominently thickened in the right kidney. The cytoplasm of the podocyte of the left kidney was markedly increased and had free ribosomes, developed Golgi apparatus and rough endoplasmic reticulum. 3. At the 30 days, the section of the glomeruli were more enlarged in the left kidney than in the right. 4. At the 20 day, the nuclear section of the podocytes were markedly enlarged in the right kidney, but those of the left kidney were diminished. The mitochondrial section of the podocytes were prominently increased in the right kidney. 5. The nuclear section of the parietal layer lining cells was no significant change in the right kidney. That of the left kidney was increased at the 20 days and decreased at the 40 days. The nuclear section of glomerular endothelium of the left kidney increased earlier than the right. 6. In the morphometry of the control kidney, the section areas, long and short diameters, the nuclear section, the mitochondrial section of the proximal tubule cells, and the changes of those were more large in the right kidney than in the left. 7. The luminal secretory vesicles and peroxisomes of the left kidney were more than the right at the 20 days. The increase of mitochodrial section in the proximal tubule cells of the left kidney was more prominent than the right. The large cytoplasmic vacuoles were more prominent in the left kidney than in the right. 8. The thickness of cytoplasm and brush border was more thick in the control left kidney than in the control right. The change of cytoplasmic thickness of the left kidney was increased earlier than in the right and both kineys were increased in the thickness of brush border at the 30 days.