• Toxicological Research
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• 제5권2호
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• pp.79-87
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• 1989

Changes in urinary $Na^+$ and $K^+$ excretions, renal cortical microsomal $Na^+$ -K-ATPase activity, cortical tissue electrolyte content and plasma aldosterone level were studied in rats treated with CdCl2 (2 mg Cd/kg/day, s.c. injection) for 7-14 days. After 7 days of cadmium exposure, urinary excretion of $Na^+$ was markedly reduced. This change was accompanied by an increase in $Na^+$-$K^+$-ATPase activity, a fall in tissue $Na^+$ content, a rise in tissue $K^+$ content and an elevation of plasma aldosterone level.

• Archives of Pharmacal Research
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• 제17권2호
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• pp.124-130
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• 1994

Plasma phamacokinetics and renal excretion of theophylline (TP) and its metabolities were ivnestigated in rats. Plasma concentrations of TP declined in a monoexponential manner, while those of 1-methyluric (MU) and 1,3-dimethyluric(DMU) declined in a biexponential manner upon respective iv bolus injection of each compound at 6mg/kg dose. The total body clearances $(CL_r)$ of the metabolites were 4-6 fold larger than that of TP, while the distribution volumes of them at steady-state $(Vd_{ss})$ were 40-50% smaller than that of TP. The metabolites showed their plasma peaks in 30 min after iv injection of TP indicating than that to MU. Renal excretion of TP and its metabolites was studied in urine flow rate (UFR)-controlled rats. The renal clearance $(CL_r)$ of TP was inversely related to pasma TP concentrations, and much smaller than the glomerular filtration rate (GFR) suggesting tubular secretion and profound reabsorption in the renal tubule. The $(CL_r)$ of each metabolite also showed that inverse relationship, but far exceeded GFR suggesting that tubular secretion than GFR by ip injection of probenecid (142.7 mg/kg). It supports that the metabolies are secreted in the renal tubule, and suggests that they share a common transport system in their sectrtion processes with probenecid. On the other hand, the $(CL_r)$ of TP was not affected significantly by the probenecid treatment. Considering the inverse relationship of TP between the $(CL_r)$ and its ploasma concentrations,no effect of probenecid on $(CL_r)$ of TP is most likely due to negligible contribution of the secretion to the overall $(CL_r)$ of TP.

• The Korean Journal of Physiology and Pharmacology
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• 제6권1호
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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.

• 대한약리학회지
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• 제5권1호
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• pp.57-64
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• 1969

Acetylsalicylic acid, administered intravenously in a dose of 120 mg+250 mg/h, markedly decreased the urinary excretion of sodium and chloride, and slightly depressed potassium excretion, so that the ratio of urinary concentrations of potassium to sodium increased after ASA. Osmolar and free water clearances also diminished during water diuresis, and free water reabsorption $(T^cH_2O)$ decreased after ASA during mannitol diuresis. Glomerular filtration rate and urine flow rate changed little. When infused directly into a renal artery, ASA exhibited identical action on both kidneys, indicating that the renotropic action is mediated by some endogenous humoral agents or by some metabolites of ASA. A dose of 100 mg i.v. of spironolactone, a aldosterone antagonist, slightly reversed the renal reflect when given during maximum action of ASA. Ethacrynic acid could display its full diuretic action unhindered during maximum ASA action. Above observations lead to the suggestion that acetylsalicylic acid might release aldosterone and the action on electrolyte excretion may be mediated by the mineralocorticoid.

• 약학회지
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• 제34권2호
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• pp.88-101
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• 1990

Captopril, angiotensin converting enzyme (ACE) inhibitor, when given intravenously in dog, elicited the diuretic action along with the increases of glomerular filtration rates (GFR), renal plasma flow (RPF) and osmolar clearances (Cosm) with no changes of free water clearnces ($C_{H_2O}$), and then captopril produced the enlargement of excretion rates of electrolytes in urine and the reduction of reabsorption rates of electrolytes in renal tubles. Captopril, when given into a renal artery, exhibited no changes of renal function in the experinental kidney, whereas diuretic action with the same mechanism as shown in intravenous captopril in control kidney. Captopril, when injected into a carotid artery, showed increases in rates of urine flow in a small does which did not affect on renal action when it was administered intravenusly. Diuretic action induced by captopril was not influenced by renal artery denervation, propranolol and angiotensin II inhibiters. Above results suggest that captopril produced diuretic action along with renal hemodynamic changes by slight contraction of vas efferense and reduction of reabsorption rate of electrolytes in renal tubules, especilly distal tubules, that may be mediatedby endogenous substances.

• 대한본초학회지
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• 제20권3호
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• pp.43-49
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• 2005

Objectives : The present study was carried out to determine if Glycyrrhizae Radix extract exerts beneficial effect against the ischemia-induced acute renal failure in rabbits. Glycyrrhizae Radix was known to reinforce the function of the spleen and replenish Qi, remove heat and counteract toxicity, dispel phlegm and relieve cough, alleviate spasmodic pain, and to moderate drug actions. It's indications are weakness of the spleen and the stomach marked by lassitude and weakness; cardiac palpitation and shortness of breath; cough with much phlegm: spasmodic pain in the epigastrium, abdomen and limbs: carbuncles and sores. It is often used for reducing the toxic or drastic actions of other drugs. Methods : Antioxidative effect of 3% concentration of Glycyrrhizae Radix extract was measured. Rabbits were treated with Glycyrrhizae Radix extract via i.v., followed by renal ischemia/reperfusion, and the changes of urine volume, serum creatinine levels, glomerular filtration rate(GFR), fractional Na+ excretion$(FE\;Na^+)\;and\;K^+\;excretion(FE\;K^+)$ in ischemia/reperfusion induced acute renal failure were measured. Results : Renal ischemia/reperfusion caused increase of serum creatinine level, which was accompanied by a reduction in glomerular filtration rate(GFR). The fractional excretion of $Na^+\;and\;K^+$ increased in ischemia-induced animals, which was partially prevented by Glycyrrhizae Radix extract treatment. Conclusions : These results indicate that lipid peroxidation plays a critical role in ischemia-induced acute renal failure. Glycyrrhizae Radix extract exerts the protective effect against acute renal failure induced by renal ischemia/reperfusion, and its effect may be attributed to an antioxidant action.

• 약학회지
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• 제23권1호
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• pp.31-39
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• 1979

Bethanidine was administered into the lateral ventricle of the rabbit brain for the investigation of the effect on the renal function in doses ranging from 0.1 to 1.0mg/kg. In a dose of 0.1 mg/kg, bethanidine did not exhibit significant changes on the renal function of the rabbit, on the other hand, in the doses of 0.3 and 1.0mg/kg bethanidine elicited the reduction of renal plasma flow and glomerular filtration rate with a marked antidiuresis, at the same time bethanidine produced the decrement of urinary sodium and potassium excretion. After intravenous pretreatment of phentolamine, intraventricular bethanidine in a dose of 0.3mg/kg did not produced the antidiuresis and the decrement of urinary sodium and potassium excretion, wherease renal plasma flow and glomerular filtration rate reduced as before of phentolamine pretreatment although the durations of their reduction were shortened. These observations suggest that bethanidine induces the antidiuresis through the centrally mediated mechanism which interposed other factors in addition to sympathetic stimulation affected by phentolamine, alpha adrenergic blocking agent.

• 약학회지
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• 제22권3호
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• pp.138-147
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• 1978

Bethanidine, which is known as a sympathetic blocking agent, was injected into the vein of a dog in an attempt to investigate the influence on renal funciton. Bethanidine resulted in an increased urine flow and glomerular filtration rate, and it produced an increase of urinary sodium and potassium excretion and a decrease of reabsorption rate of sodium and potassium in renal tubules, whereas renal plasma flow showed no significant changes. After pretreatment of phentolamine, a specific alpha adrenergic blocking agent, bethanidine did not significantly increase glomerular filtration rate and diuresis, significantly increased urinary sodium and potassium excretion although the magnitudes were reduced when compared with that of bethanidine alone. In conclusion, bethanidine-induced diuresis appears to be the result of an inhibited tubuler reabsorpting of electrolytes within the kidney through its sympathetic blockade of renal nerves and of an increased glomerular filtration rate, which was caused by the constriction of vas efferense in the glomeruli.

• The Korean Journal of Physiology
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• 제19권2호
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• pp.173-187
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• 1985

Renal compensatory adaptation caused by ablation of a part of renal mass has long been known in the field of the compensatory renal hypertrophy or hyperplasia. Many reports were found on the chronic mechanisms on the compensatory renal hyperfunction after exclusion of the contralateral kidney. However the mechanism(s) of the acute compensatory hyperfunction after contralateral exclusion has not yet been clarified. In the present experiment, we have tried to prove the possibility of the involvement of the renin-angiotensin system and/or prostaglandin system in the control mechanism of the acute compensatory renal hyperfunction after contralateral kidney exclusion. There were found different responses of the renal hyperfunction by contralateral renal pedicle or ureteral occlusion. Contralateral renal pedicle or ureteral occlusion caused a sustained increases of the urinary volume, sodium and potassium excretion, while the magnitude of the changes was different quantitatively by the maneuvers. Blood collection affected on the acute compensatory renal responses after ureteral as well as renal pedicle occlusion. Plasma prostaglandin $E_2$ level was not changed by the contralateral renal pedicle or ureteral occlusion. Urinary excretion of Prostaglandin $E_2$, the indices of renal prostaglandin biosynthesis, was not changed by the contralateral renal pedicle occlusion, but increased without significance by the contralateral ureteral occlusion. Acute renal compensatory responses after contralateral renal pedicle occlusion were blocked by the pretreatment of indomethacin. Plasma renin activity increased after contralateral ureteral occlusion, but the pattern of the increases was the same as in the time-control group. Plasma renin activity after contralateral renal pedicle occlusion did not change by the time sequence. SQ 20,881, an angiotensin I converting enzyme inhibitor, blunted the contralateral renal responses after the renal pedicle occlusion. Bilateral renal denervation abolished the contralateral renal responses after the renal pedicle occlusion. The above data suggest that there is no direct evidence to support the involvement of the renin-angiotensin system and/or prostaglandin system for the acute compensatory renal hyperfunction after contralateral kidney exclusion, and that the functional changes of the intact kidney may be caused by a humoral substances, or other mechanisms by afferent renal nerve activity originating from the treated kidney.

• Journal of Nutrition and Health
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• 제31권3호
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• pp.253-262
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• 1998

This study was performed to investigated the effect of dietary fat sources on renal senescence in aged rats. Seventeen month old male Sprague-Dawley rats were divided into 3 groups according to urinary protein excretion. Four month old rats were used as a control group. The rats were fed one of three different experimental diets ; 20% beef tallow, 20% corn oil 20% fish oil diet. They were fed experimental diets ad libitum for 16 weeks . The results are summarized as follows. Serum lipid concentrations were higher in aged rats than in control rats, with the beef tallow group showing the highest level, followed by the corn oil and fish oil groups. Old rats showed higher HDL and lower LDL levels than the control groups. Age and dietary fat had no effect on VLDL. GFR for the both age groups were increased with experimental period with the beef tallow group showing the highest value. Urinary protein excretion was also increased with experimental period in both age groups. There was a large increase in urinary protein in old rats that were fed beef tallow and corn oil, but not in old rats fed fish oil. On the contrary , the effect of dietary fat on urinary protein was not found in control groups. There was individual susceptibility in the effect of dietary fat on urinary protein. Old rats fed beef tallow with high initial urinary protein showed highest increase, but , the change was not significant in rats with a low initial value . It was also found that the increase was kept low in rats of the fish oil group with high initial urinary protein. The corn oil group showed in between values. There were no differences in urine and renal tissue concentrations of TXB2 . Aged rats showed a tendency of having higher urinary PGE2 excretion and lower renal cortex content. Since higher PGE2 excretion was reported to be associated with decreased renal function, this might suggest that the aged rats show renal function reduction. Light microscopic examination showed that glomerular segmental sclerosis, mesangial matrix expansion and tubular atrophy were more frequently present in aged rats, and that these changes were more significant in the beef tallow group, followed by corn oil and fish oil groups. The percentage of urinary protein excretion was increased in aged rats in association with increased glomerular sclerosis and mesangial matrix . This change could be partly due to a change in eicosanoids metabolism . Therefore, modification of dietary fat could affect the eicosanoids metabolism in kidney and renal senescence.