• Archives of Pharmacal Research
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• v.17 no.2
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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.

• YAKHAK HOEJI
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• v.41 no.4
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• pp.498-511
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• 1997

The effects of UK 14,304, an ${\alpha}_2$-adrenergic agonist, on renal function were investigated in dogs. UK 14,304, when given intravenousely($15.0{\mu}g/kg,\;50{\mu}g/kg$), produced the increase of urine flow accompanied with the marked augmentation of free water clearance ($C_{H_2O}$) and reabsorption rates of sodium in renal tubules ($R_{Na}$), and the remarkable decrease of osmolar clearance ($C_{osm}$) and the amounts of sodium excreted in urine ($E_{Na}$). UK 14,304 given into a renal artery($1.5{\mu}g/kg,\;5.0{\mu}g/kg$) elicited the increase of urine flow with the augmentation of $C_{H_2O}$ in both kidney. UK 14,304, when administered into carotid artery($3.0{\mu}g/kg,\;10.0{\mu}g/kg$). exhibited the same aspect as shown in intravenous UK 14.304 at smaller dose than the intravenous dose. Diuretic action of intravenous UK 14,304 were produced together with increase of $C_{H_2O}$ in situation of water diuresis too, changes of renal function in this state were the increase of $C_{osm},\;E_{Na},\;and\;E_K$ (excreted amounts of potassium in urine), and the decrease of $R_{Na}\;and\;R_K$, these were different appearances from situation of saline diuresis. Diuretic action of intravenous UK 14,304 were blocked completely by post or pretreatment of yohim-bine, ${\alpha}_2$-adrenergic blocking agents, and inhibited by pretreatment of vasopressin, antidiuretic hormone. Above results suggest that UK 14,304 produces the diuretic action by the inhibition of vasopressin secretion and suppression of electrolytes reabsorption of electrolytes in renal tubules mediated with central ${\alpha}_2$-adrenoceptor in dog.

• YAKHAK HOEJI
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• v.29 no.3
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• pp.130-143
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• 1985

Bumetanide, when given intravenously in dogs, induced a potent diuresis with an increased amounts of sodium and potassium excreted in urine due to inhibition of reabsorbing them in renal tubule. Furthermore, clearances of osmolar substance and para-aminohippuric acid were increased, but clearace of free water diminished without any change of creatinine clearance. Bumetanide, administered directly into a renal artery, elicited diuresis only in the infused(experimental) kidney by the same mode of action as in the intravenous cases in renal function of the dog. Renal effects of intravenous bumetanide after pretreatment with the small dose of indomethacin (5.0mg/kg) revealed reduction only in clearance of paraaminohippuric acid. However the much dose of indomethacin (5.0mg/kg+5.0mg/kg/hr) or arachidonic acid showed a significant inhibition in the change rates of all renal function by bumetanide. Morover, pretreatment of probenecid also made a marked reduction in renal effects induced by bumetanide. From the above results, it is thought that bumetanide causes diuretic action due to dual mechanism inhibiting reabsorption of electrolytes in loop of Henle and increasing blood flow in kindney, that are provoked through the mediation of prostaglandins.

• Journal of Pharmaceutical Investigation
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• v.1 no.1
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• pp.85-89
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• 1971

The renal action of furosemide was investigated in the chicken, a species which has poorly developed loops of Henle and only rudimentary counter-current system in the kidney. Furosemide was infused into a hindleg vein, which is known to lead to the peritubular capillaries, forming renal portal system. A dose of 0.03 mg/kg/20 min. furosemide elicited a profound diuresis with saluresis, limited only to the infused side. This action rests on the inhibition of sodium reabsorption in the tubules, as the GFR remained unchanged or even decreased. It is thus inferred that the action of furosemide on Henle's loop contributes to the overall diuretic action only a negligible degree.

• Journal of Pharmaceutical Investigation
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• v.1 no.1
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• pp.34-46
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• 1971

The existence of oxytocin in the pituitary gland of chicken has been ascertained, but its physiological roles are still obscure. In the study the action of oxytocin on renal function of the chicken was investigated during water diuresis, utilizing clearance and the Sperber technique. The results obtained are summarized as follows: Oxytocin, like in many species of mammals, elicited a profound diuretic response in the chicken. Urine flow, excretion of electrolytes, as well as glomerular filteration rate increased, with intravenous infusion of $3{\sim}10\;m{\mu}/kg/min$. Oxtocin, infused into the renal portal circulation via hindleg vein in a dose of $3{\sim}13\;m{\mu}/kg/min$. elicited marked increase in urine flow, glomerular filteration rate and sodium excreted in the urine. The diuretic effect was more pronounced in the infused side. It is suggested that diuretic response to oxytocin in the chicken results from dual action of oxytocin: increase of GFR and inhibition of sodium reabsorption on the renal tubule. The possibility that oxytocin might act through some endogenous substances could be ruled out.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.4
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• pp.513-516
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• 1994

The effects of the prevention of micelle formation and bile acid reabsorption, by using cholestyramine (CHOLN), a bile acid binding polymer, on the plasma lipid of Single Comb White Leghorn male chicks given diets containing medium chain triacylglycerol (MCT) and long chain triacylglycerol (LCT) were investigated. Corn oil and glyceryl tricaprylate were used as LCT and MCT sources, respectively. Plasma HDL cholesterol was reduced by CHOLN in all treatments. Plasma LDL cholesterol was reduced by CHOLN in chicks given LCT diet but not in MCT diet which could be accounted to the reduced plasma total cholesterol in LCT diet with CHOLN. It is concluded that bile acid binding does not alter the cholesteremic effect of MCT in the plasma of chicks.

• The Korean Journal of Malacology
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• v.24 no.1
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• pp.33-40
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• 2008

Ultastructural studies of oocyte degeneration and follicle cells in female Spisula sachalinensis are described for clams collected from Jumunjin, Gangwondo, Korea. The follicle cells playan integral role in vitellogenesis and oocyte degeneration by assimilating products originating from the degenerated oocytes (thus allowed the transfer of yolk precursors needed for vitellogenesis). The functions of the follicle cells include phagocytosis and intracellular digestion of products originating from oocyte degeneration. During the period of oocyte degeneration, follicle cells of this species probably have lysosomal systems for the breakdown and reabsorption of various phagosomes(phagolysosomes) in the cytoplasm for nutrient storage; this process has been observed in other bivalves.

• The Korean Journal of Pharmacology
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• v.13 no.2
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• pp.35-39
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• 1977

Cyclic adenosine monophosphate (cAMP), known as a versatile regulator of cellular processes and as a secondary messenger of various hormones and other biogenic agents, such as prostaglandins and histamine, induced prompt and transient antidiuresis followed by mild natriuresis and diuresis, when it was administered into the lateral ventricle of the rabbit in doses ranging from $100\;{\mu}g$ to 1 mg. The initial antidiuresis was brought about by the systemic hypotension, whereas the secondary diuresis seemed to be resulted from the decreased tubular reabsorption of sodium, suggestive of participation of certain endogenous natriuretic agent. This observation suggests that cAMP might be involved in the center-mediated renal action of prostaglandins.

• Korean Journal of Veterinary Research
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• v.35 no.4
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• pp.729-733
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• 1995

This study was carried out to determine the effect of renal ischemia on renal function and excretion of amino acid in rabbit. The animal models of renal ischemia induced experimentally by clamping the renal artery for different lengths of time. These results were summarized as follows: 1. Ischemia for 30 or 60 min produced a polyuria which is accompanied by an increase in $Na^+$ excretion. Glomerular filtration rate (GFR) and p-aminohippurate plasma($C_{PAH}$) were not altered by 30 min of ischemia, indicating that transient ischemia results in a marked tubular dysfuction before a reduction in GFR or renal blood flow. 2. Reabsorption of glucose and amino acids such as alanine and lysine was markedly reduced after 30 min of ischemia, and the effect was more pronounced after 60 min of ischemia.

• Clinical and Experimental Pediatrics
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• v.50 no.5
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• pp.430-435
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• 2007

Even though we drink and excrete water without recognition, the amount and the composition of body fluid remain constant everyday. Maintenance of a normal osmolality is under the control of water balance which is regulated by vasopressin despite sodium concentration is the dominant determinant of plasma osmolality. The increased plasma osmolality (hypernatremia) can be normalized by the concentration of urine, which is the other way of gaining free water than drinking water, while the low plasma osmolality (hyponatremia) can be normalized by the dilution of urine which is the only regulated way of free water excretion. On the other hand, volume status depends on the control of sodium balance which is regulated mainly by renin-angiotensin-aldosterone system, through which volume depletion can be restored by enhancing sodium retention and concomitant water reabsorption. This review focuses on the urine concentration and dilution mechanism mediated by vasopressin and the associated disorders; diabetes insipidus and syndrome of inappropriate antidiuretic hormone secretion.