• 약학회지
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• 제45권2호
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• pp.205-213
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• 2001

The dopaminergic receptors were consisted of two distinct subtypes, $D_1$and $D_2$, each having different function. The present study was attempted to investigate the effects of R(-)-2,10,11-trihydroxy-N-n-propylnoraporphine (TNPA), a dopamine $D_2$receptor agonist, on renal function in dog. TNPA (5.0~15.0 $\mu$g/kg), when given into the vein, produced a dose-dependently antidiuresis along with the decrease in osmolar clearance ( $C_{osm}$) and urinary excretion of sodium and potassium ( $E_{Na}$ , and $E_{K}$). It also increased reabsorption rates of sodium and potassium in renal tubules ( $R_{Na}$ , $R_{K}$) without any changes in glomerular filtration rate (GFR), renal plasma flow (RPF) and free water clearance ( $C_{H2o}$). TNPA (0.5~1.5 $\mu$g/kg/min) infused into a renal artery decreased urine flow both in the experimental and the control kidneys. TNPA (1.5~5.0 $\mu$g/kg) administered via the carotid artery also greatly exhibited antidiuresis even at intravenously ineffective doses. Changes of renal function by TNPA given into both the renal artery and the carotid artery were almost the same aspect to those induced by intravenous TNPA. These results obtained from the present study suggest that TNPA produces antidiuresis by increasing the reabsorption rates of electrolytes in renal tubules, mainly distal tubule, through changing of central function.unction.

• 약학회지
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• 제31권6호
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• pp.376-393
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• 1987

This study was performed in order to investigate the effect of nifedipine, a vasodilating drug which acts through calcium antagonism, on renal function using mongrel dog. Nifedipine, when given interavenously in doses ranging from 1.5 to 5.0$\mu\textrm{g}$/kg, elicited diuresis along with less changes of glomerular filtration rate and significant increases of renal plasma flow, so that the filtration fraction(FF) decreased significantly, at the same time both osmolar and free water clearances increased, and amount of sodium, potassium and calcium excreted in urine increased significantly. Nifedipine, when infused into a renal artery in doses from 0.05 to 0.15$\mu\textrm{g}$/kg/min, exhibited identical responses to the actions of intraveneous nifedipine except significant increase of glomerular filtration rate and no change of FF, which was confined only to the infused kidney. The renal action of nifedipine into a renal artery were not influenced by renal denervation, decreased significantly by ouabain, Na$^+$-K$^+$-ATPase inhibitor, which was given into a renal artery. Nifedipine infused into a renal artery in dog pretreated with propranolol i.v. produced diuresis associated with the increase of electrolytes excretion by reduction of electrolyte reabsorption and with no changes of glomerular filtration rate and renal plasma flow. Thus, it is concluded that nifedipine infused into a renal aretery produces diuretic action along with both improvement of hemodynamics and inhibition of electrolytes reabsorption, which may be related to sympathetic $\beta$-receptor or Na$^+$-K$^+$-ATPase activity because the action of nifedipine in kidney is blocked by propranolol or ouabain.

• Biomolecules & Therapeutics
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• 제5권4호
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• pp.351-356
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• 1997

This study was performed in order to investigate the effect of renal denervation on diuretic action of UK 14, 304, $\alpha$$_2$-Adrenergic Agonist, administered into the vein and the carotid artery in dog. The diuretic action of UK 14, 304 administered into the vein or the carotid artery was reversed to the antidiuretic action by renal denervation, this time, the decrease of N $a^{+}$excretion amounts in urine ( $E_{Na}$ ) and the increase of N $a^{+}$ reabsorption rates in renal tubule ( $R_{Na}$ ) were exhibited. This results suggest that central diuretic action of UK 14, 304 is mediated by renal nerves and the antidiuretic action of UK 14, 304 in denervation kidney is caused by the increase of N $a^{+}$reabsorption rates ( $R_{Na}$ ) in renal tubules in dog.n dog.

• 대한약리학회지
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• 제7권1호
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• pp.67-76
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• 1971

The excretion of uric acid in man has been of great interest because of its importance as an end product in purine metabolism as well as of its role in causing gout. There are many differences in the modes of renal handling of urate among various species of animals. Uric acid actively secreted by the renal tubules of most vertebrate including amphibians, reptiles, and birds. On the other hand, in most mammals net tubular reabsorption of urate appears to be occurred with some exception, such, as Dalmatian dog. In the rabbits, however, the mechanism of renal excretion of uric acid has long been a subject of controversial results. Within a given group it was possible to find individuals with either net secretion or net reabsorption of urate depend on the experimental conditions. Excretion of urate can be depressed or enhanced by a variety of drugs belonging mainly to the aromatic acid group. Diodrast, probenecid, cinchophen and salicylates have been reported as uricosuric agents, on the other hand, lactate, benzoate, pyrazinoic acid, acetazolamide and chlorothiazide are known to be contraindicated to use for the patient with gout since these agents depress the excretion of uric acid from the kidney. However, complex and sometimes the paradoxical effects on the urate excretion by those above mentioned drugs are not uncommon. The experiments were designed to investigate the mechanisms of renal handling of urate as well as the effects of variety of drugs on the tubular transport of uric acid in the rabbits. Male or female white rabbits, from 1.5 to 2.5 kg in weight, were used. The experimental methods used in these studies were clearance, stop-flow, and retrograde injection techniques. The effects of saline, salicylate, chlorothiazide and probenecid were investigated in each experimental conditions. Results of the experiments were summarized as follows; 1. In the rabbits, the rate of urate clearance was always lower than the rate of inulin clearance. The filtration fraction of the urate was one third on an average, therefore, it is estimated that approximately two thirds of filtered urate was reabsorbed. 2. In the kidneys of rabbits, the urate clearance was increased significantly by administration of chlorothiazide and decreased by probenecid. The administration of salicylate had no effect on the rate of urate clearance. The filtration fraction of urate was increased by chlorothiazide and decreased by probenecid. 3. In the stop-flow studies, the U/P ratio of urate was higher than the U/P ratio of inulin in the proximal region, indicating the secretion of uric acid in the proximal tubules. The proximal peak was increased by chlorothiazide and inhibited by probenecid.4. In the retrograde injection studies, the reabsorption of urate in the proximal region was observed, and these reabsorptive transport of urate was depressed by either probenecid or by chlorothiazide. 5. No distal tubular activity was observed under any of these experimental conditions concerning urate transport. The results of these experiments show that probenecid inhibits both secretory and reabsorptive transport of uric acid in the kidney of the rabbits. The enhancement of secretory transport of urate by chlorothiazide in the clearance study was due to the secondary action of chlorothiazide which inhibits the reabsorptive transport of urate in the proximal tubules. It is evident that the urate transport in the kidneys of rabbits is bidirectional nondiffusive flux both secretory and reabsorptive directions in the proximal tubules.

• Korean Journal of Acupuncture
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• 제23권1호
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• pp.45-57
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• 2006

Objective : This study was undertaker to determine if Juglandis Semen herbal acupuncture (JSA) exerts protective effect against alterations in membrane transport function in rabbits with mercury-induced acute renal failure. Methods : Nephrotoxicity was induced by subcutaneous administration of Hg(a single dose of 10mg/kg) and JSA was performed at both sides of Shenshu($(BL_{23})$, Sinsu) for 7 days. Results: The administration of Hg at a subcutaneous single dose of 10 mg/kg caused a reduction in GFR to 12% of the basal value and an increase in fractional $Na^+$ excretion to 8.9-fold, indicating generation of acute renal failure. When JSA were given for 7 days prior to Hg administration, such changes were significantly attenuated. The fractional excretion of glucose and phosphate was increased to approximately 102- and 35-fold, respectively, in rabbits treated with Hg alone. The increase in rabbits treated with Hg following ISA are significantly lower than that in animals treated with Hg alone. Uptakes of glucose and phosphate in purified isolated brush-border membrane and $Na^+-K^+-ATPase$ activity in microsomal fraction were inhibited in rabbits treated with Hg alone, suggesting that impairment in proximal reabsorption of glucose and phosphate is resulted from a direct damage of membrane transport carriers and disruption of the normal $Na^+$ gradient. Such changes were prevented by JSA. Conclusion These results indicate that the administration of Hg causes impairment in reabsorption of solutes in the proximal tubule via the generation of reactive oxygen species. JSA provides the protection against the Hg-induced impairment in proximal reabsorption, and its effect may be resulted from its antioxidant action.

• 동의생리학회지
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• 제14권2호통권20호
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• pp.189-198
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• 1999

Aminoglycosides, including gentamicin, have been used as antibiotics for the various infections by gram-negative bacteria. However, there are some restrictions for using these drugs. Gentamicin, a typical aminoglycoside, has the side effect of nephrotoxicity, including polyuria, glycosuria, proteinuria, glomerulonephritis, and uremia. The aims of this study were to examine the prevention or reduction effects of Jinmootang on the gentamicin-induced nephrotoxicity and to investigate the possible mechanisms on the effect of Jinmootang. The subcutaneous injections of 60mg of gentamicin per kg of boby weight to Sprague-Dawley rats for 8 days induced typical symptoms of nephrotoxicity by aminoglycosides. 0.6ml of water extract Jinmootang (100ml/chup) was orally treated in the experimental animal. 24-hour urine was collected with the metabolic cage and plasma was sampled from the abdominal aorta. The plasma concentration of sodium was significantly decreased by the treatment of gentamicin but it was not-significantly changed by the treatment of Jinmootang to the animal. The concentration of potassium was greatly decreased in the gentamicin-treated animals. However. it was returned to the normal level in the Jinmootang-treated animals. The concentrations of creatinine and urea were increased by gentamicin treatment. But, Jinmootang reduced these concentrations. Nevertheless, the osmolalities of plasma in both group were not different from each other. Even though the plasma concentration of aldosterone was not significantly changed, the mean value was increased by the gentamicin intoxication. The concentration of aldosterone was decreased by the treatment of Jinmootang. The reduction of aldosterone level in plasma could be a factor to improve the hypokalemia. The fractional excretion of potassium was much higher than normal by the treatment of gentamicin and it was decreased by 50% in the Jinmootang-treated rats. Therefore, the reabsorption of potassium was significantly increased by the treatment of Jinmootang, even though the filtered load of potassium in the experimental group was much highter than control. Even though the concentration of plasma aldosterone was decreased by the treatment of Jinmootang, the fractional excretion of sodium was not increased, slightly lower. These data suggested that Na reabsorption was increased in the proximal tubule by Jinmootang. The filtered load of glucose in the Jinmootang-treated group was greater than in control. Nevertheless, the fractional excretion of glucose in the experimental group was not different from that in control. These results indicate that glucose reabsorption was increase in the proximal tubule by Jinmootang treatment. The results of this study suggest that Jinmootang could improve the some nephrotoxic symptoms induced by gentramicin treatment. Hypokalemia, the reduced glomerular filtration rate, and dysfunctions of renal proximal tubule and distal nephron were significantly recovered to normal level. The increase of glomerular filtration rate by Jinmootang might contribute to eliminate the waste product, including creatinine and urea, and/or gentamicin through the kidney.

• Biomolecules & Therapeutics
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• 제2권3호
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• pp.229-235
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• 1994

In dogs, renal denervation did not affect the diuretic action accompanied with renal hemodynamic chanties and inhibition of electrolytes reabsorption rates in renal tubules by methoxyverapamil infused into the vein or into a renal artery, while renal denervation blocked the antidiuretic action due to the decreased free water and osmolar clearances along with the reduced sodium amounts excreted in urine by methoxyverpamil infused into the carotid artery. These experimental results suggest that methoxyverapamil may cause diuresis by direct action in kidney but the antidiuretic action through central function mediated by renal nerves.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2001년도 International Symposium on Signal transduction in Toxicology
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• pp.155-155
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• 2001

Acute cadmium exposure has been shown to increase sodium reabsorption in kidney through increase in aldosterone secretion in human and rodents. However, the antinatriuresis is not completely explained by hyperaldosteronism. Moreover, it is still controversial that the increase in plasma aldosterone concentration is mediated by the renin-angiotensin-aldosterone system(RAAS).(omitted)

• 미생물학회지
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• 제7권3호
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• pp.125-134
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• 1969

The effect of heat treatment on membrane permeabilities of yeast's cells was studied, the amounts of efflux out of yeast cells were put to analysis, and fraction survival was also counted by viable plate counting method. Effects of nutritional substances on thermally injured yeast cells were also investigated under the highlight of reabsorption mechanism, then the relationship between permeability and surviving action in injured yeast cells are discussed.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.319.2-319.2
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• 2002

Chitin is a major component of the shells of crustacea such as crab. shrimp and crawfish. Renal dipeptidase (RDPase. EC 3.4.13.19), an ectoenzyme of renal proximal tubules. is covalently bound to outer leaflet of lipid bilayer via glycosylphosphatidylinositol (GPI)-anchor. The biological role of RDPase was suggested as the hydrolysis of dipeptide into free-amino acids before renal reabsorption. The underlying biochemical mechanism of decreased RDPase release was suggested as nitric oxide (NO) production. (omitted)