• Environmental Mutagens and Carcinogens
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• v.25 no.2
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• pp.60-65
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• 2005

The human solute carrier, SLC41Al, is a $Mg^{2}+$ transporter that is regulated by extracellular magnesium. Although intracellular magnesium plays a fundamental role in cellular metabolism, little is known about how $Mg^{2}+$ is taken up and controlled by cells. Magnesium plays a fundamental role in cellular metabolism so that its control within the body is critical. Magnesium homeostasis is principally a balance between intestinal absorption of dietary magnesium and renal excretion of urinary magnesium. The kidney, mainly the distal convoluted tubule, controls magnesium reabsorption. Although renal reabsorption is under the influence of many hormones, selective regulation of magnesium transport is due to intrinsic control involving transcriptional processes and synthesis of transport proteins. Using microarray analysis, identification of the genetic elements involved with this transcriptional control has been begun. SLC41A1(GenBank Accession No. AJ514402), comprises 10 putative transmembrane domains, two of which are highly homologous to the integral membrane part of the prokaryote transports $Mg^{2}+$ and other divalent cations $Sr^2+,\;Zn^2+,\;Cu^2+,\;Fe^2+,\;Co^2+,\;Ba^2+,\;and\;Cd^2+,\;but\;not\;Ca^2+,\;Mn^2+,\;and\;Ni^2+.$ Transport of $Mg^{2}+$ by SLC41Al is rheogenic, voltage dependent, and not coupled to Na or Cl. Expressed SLC41Al transports a range of other divalent cations: $Mg^{2+},\;Sr^{2+},\;Zn^{2+},\;Cu^{2+},\;Fe^{2+},\;Co^{2+},\;Ba^{2+},\;and\;Cd^{2+}$. The divalent cations $Ca^{2+},\;Mn^{2+},\;and\;Ni^{2+}$and the trivalent ion $Gd^{3+}$ did not induce currents nor did they inhibit $Mg^{2+}$ transport. The nonselective cation $La^{3+}$ abolishes $Mg^{2+}$ uptake. Computer analysis of the SLC41Al protein structure reveals that it belongs to MgtE protein family & suggested that the human solute carrier, SLC41Al, might be a eukaryotic $Mg^{2+}$ transporter closely related $(60-70\%)$ protein encoded by SLC41A2 is a $Mg^{2}+$ transporter that might be involved in magnesium homeostasis in epithelial cells also transports a range of other divalent cations: $Ba^2,\;Ni^2,\;CO^2,\;Fe^2,\;or\;Mn^2,\;but\;not\;Ca^2,\;Zn^2,\;or\;Cu^{2+}$ that may have related functional properties.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.3
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• pp.325-335
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• 1997

Evidence for the existance of at least two subclasses of renal adenosine receptors has been presented. N-6-cyclohexyladenosine (CHA) is a relatively selective $A_1$ adenosine agonists, whereas 5'-N-ethylcarboxamidoadenosine (NECA) acts as a preferential agonist of $A_2$ adenoisne receptor. N6-(L-2-phenylisoproryl)-adenosine (PIA) almost unselectively activates both $A_1\;and\;A_2$ adenosine receptors at micromolar concentrations. During the characterization of adenosine receptor in the kidney, we have discovered a novel phenomenon, that is, an intramuscular administration of CHA for 3 days caused a diuresis and a suppression of urinary concentrating ability. To further characterize this novel phenomenon, an intramuscular administration of adenosine and other adenosine angonists, PIA and NECA, and prior treatment of adenosine antagonists, caffeine, theophylline and 1,3-diethyl-8-phenyl-xanthine (DPX) were performed. Systemic administration of CHA, PIA, and NECA for 3 days caused a suppression in heart rate, blood pressure and general motor activity without change in rectal temperature. Systemic administration of CHA, 0.5, 1 and 2 mg/kg/day, for 3 days caused a dose-dependent increase in urine volume and decrease in urinary osmolarity and free water reabsorption. This phenomenon was reversible and repeatable. Administration of adenosine (40 mg/kg/day) produced no apparent effect on the renal function, whereas PIA (2 mg/kg/day) produced an similar effect to CHA on the renal function. Systemic adminstration of NECA, 0.025, 0.05 and 0.25 mg/kg/day, for 3 days caused a dose-dependent increase in urine volume and dose-dependent increases in excreted amount of creatinine, urinary osmolarity and free water reabsorption. These renal effects of adenosine agonist were maximum at second day during the drug administration. In terms of increase in urine volume and the suppression of urinary concentrating ability, NECA was potent than CHA. Prior treatment of caffeine (50 mg/kg/day) or theophylline (50 mg/kg/day) abolished the diuretic effect of CHA, whereas DPX (50 mg/kg/day) did not affect the CHA effect. CHA, 0.5 mg/kg/day, produced no change in plasma renin activity and plasma levels of aldosterone, epinephrine, and norepinephrine. These results suggest that this novel phenomenon produced by an activation of renal adenosine receptors plays an important role in urinary concentrating mechanism.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.3
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• pp.315-323
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• 1997

Central tryptaminergic system has been shown to play an important role in the regulation of renal function: $5-HT_1(5-hydroxytryptamine_1)$ receptors might seem to mediate the diuresis and natriuresis, whereas the $5-HT_2\;and\;5-HT_3$ receptors mediate the antidiuretic and antinatriuretic effects. This study attempted to delineate the role of central $5-HT_{1A}$ subtype in the regulation of rabbit renal function by observing the renal effects of intracerebrovent-ricularly(icv)-administered PAPP(p-aminorhenylethyl-m-trifluoromethytphenyl piperazine, LY165163), a selective agonist of $5-HT_{1A}$ receptors. PAPP in doses ranging from 40 to $350{\mu}g/kg$ icv induced significantly diuresis, natriuresis, and kaliuresis, along with increased renal perfusion and glomerular filtration. Systemic blood pressure was also increased. Free water reabsorption$(T^cH_2O)$, a measure of ADH(antidiuretic hormone) secretion, was increased also. Intravenous $350{\mu}g/kg$ of PAPP elicited antidiuresis and antinatriuresis together with decreased blood pressure, thus indicating that the effects of icv PAPP were brought about through the central mechanisms, not by direct peripheral effects of the drug on kidney. Ketanserin, a selective $5-HT_2$ antagonist, $40{\mu}g/kg$ icv, did not affect the renal effects of the icv PAPP. Methysergide, a non-selective $5-HT_1$ antagonist, also did not block the renal functional responses by the icv PAPP. NAN-190, a $5-HT_{1A}$ antagonist, also did not antagonized the renal action of the icv PAPP. However the increased free water reabsorption was abolished by both methysergide or ketanserin pretreatment. The increments of blood pressure by icv PAPP was blocked only by NAN-190 pretreatment. These observations suggest that the central $5-HT_{1A}$ receptor might be involved in the central regulation of rabbit renal function by exerting the diuretic and natriuretic influences.

• Journal of Nutrition and Health
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• v.47 no.2
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• pp.99-105
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• 2014

Purpose: This study was conducted in order to investigate the diuretic effects of Erythritol (ET) salt on urinary electrolyte excretion in Sprague-Dawley Rats. Methods: Animals were divided into two groups: Salt group (n = 7) and Salt + ET fed group (n = 7). Animals were provided food and water ad libitum. Supplements were administered orally to animals for one week. Results: Body weights were not statistically different between groups either on Day 1 or Day 7. However, water consumption of the Salt + ET group was significantly higher than that of the Salt group on Day 1 and Day 7. Urine volume of the Salt + ET group was approximately 27% and 38% higher than that of the Salt group on Day 1 and Day 7. In addition, we found that the total amounts of urinary electrolytes, such as sodium and potassium, of the Salt + ET group were significantly higher than those of the Salt group on Day 7. We also found that serum electrolyte concentrations did not differ between two groups. These results demonstrated that salt intake with ET was effective in increasing urinary electrolyte excretion, which might be caused by higher water intake and diuretic effect inhibiting reabsorption of water, sodium, and potassium in renal tubules. Conclusion: The results suggest that short-term supplementation of ET salt can be a potential diuretic agent by inhibiting sodium and potassium reabsorption and inducing loss of water.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.8
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• pp.1178-1182
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• 2008

The present study was designed to assess the influence of caeca on the availability of calcium, phosphorus, magnesium, manganese and copper from soybean, sunflower, rapeseed, sesame, fish and meat cum bone meal in adult roosters. The excretion of endogenous origin minerals viz., copper, magnesium, manganese and calcium was significantly (p<0.001) higher in caecectomized than in normal roosters. The difference in the endogenous excretion was 50; 60.45; 40.35 and 29.63 per cent for copper, magnesium, manganese and calcium, respectively, in caecectomized roosters. The caeca played a pivotal role in the reabsorption of endogenous origin calcium, magnesium, manganese and copper. The mechanism of phosphorus absorption by the caecal epithelium was negligible. The caecectomized roosters underestimated the bioavailability of copper in sunflower meal and manganese in almost all the test feedstuffs. The present investigation revealed that the caeca played a critical role in the absorption of minerals from vegetable protein feedstuffs which escape digestion and absorption in the small and large intestinal segments.

• The Korean Journal of Malacology
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• v.30 no.4
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• pp.333-342
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• 2014

Ultrastructural studies of oogenesis in oocytes, oocyte degeneration associated with the follicle cells in female Coecella chinensis were investigated for clams collected from Namhae, Geongsangnam-do, Korea. In this study, vitellogenesis during oogenesis in the oocytes occured by way of endogenous autosynthesis and exogenous heterosynthesis. Of two processes of vitellogenesis during oogenesis, the process of endogenous autosynthesis involved the combined activity of the Golgi complex, mitochondria and rough endoplasmic reticulum. whereas the process of exogenous heterosynthesis involved endocytotic incorporation of extraovarian precursors at the basal region of the oolema of the early vitellogenic oocytes prior to the formation of the vitelline coat. It is assumed that the follicle cells were involved in the development of previtellogenic and early vitellogenic oocytes and appear to play an integral role in vitellogenesis in the early and late vitellogenic oocytes by endocytosis of yolk precursors, and also they were involved in oocyte degeneration by assimilating products originating from the degenerated oocytes, thus allowed the transfer of york precursors needed for vitellogenesis (through phagocytosis by phagolysosomes after spawning). Follicle cells presumably have a lysosomal system for breakdown products of oocyte degeneration. and for reabsorption of various phagosomes (phagolysosomes) in the cytoplasm for nutrient storage during the period of oocyte degeneration.

• The Korean Journal of Pharmacology
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• v.16 no.2 s.27
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• pp.9-14
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• 1980

The influence of penicillin G infusion(7.5 units/min/kg) on the diuretic action of furosemide$(250{\mu}g/kg)$ in rabbits was studied to investigate the drug interaction between penicillin G and furosemide. The results were as follows: 1) There was no significant change in renal function in the penicillin G infused rabbits compared with the normal ratbit. 2) In comparison with the control group, a significant increase in ${\triangle}U_{flow},\;{\triangle}U_{Na}V,\;{\triangle}U-kV\;and{\triangle}U_{cl}V$ was noted by 30 minutes following the administration of furosemide in the penicillin G infused group. There was no significant difference in ${\triangle}C_{In},\;{\triangle}C_{PAH}$ between the two groups and ${\triangle}Na^+$ reabsorption rate was significantly decreased in the latter. The potentiating effect of penicillin G on the diuretic action of furosemide should be due to the increased luminal concentration of free form of furosemide, and it may be related to the competitive inhibition of plasma protein binding between the two drugs.

• Biomolecules & Therapeutics
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• v.9 no.1
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• pp.26-32
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• 2001

This study was investigated about the effect of glibenclamide (GLY) which is $K^{+}$ channel blocker on renal function in rabbit, GLY, when given into the vein, produced the diuretic action accompanied with the increases of amounts of N $a^{+}$ and $K^{+}$ excreted into urine ( $E_{Na}$ , $E^{K}$), and then osmolar and negative free water clearances ( $C_{osm}$, $T^{C}$$_{H2O}$), fraction excretory rates of filtered N $a^{+}$ and $K^{+}$ ( $F_{Na}$ , $F_{K}$) and ratios of $E_{K}$ against $E_{Na}$ were augmented. Filtration fraction (FF) were reduced because renal plasma flow (RPF) were not changed but glomerular filtration rates (GFR) were diminished. GLY administered into a renal artery exhibited significant reduction of urine volume along with the decreases of GFR and RPF in only experimented kidney whereas changes of renal function was not observed in control kidney. GLY given intracerebroventricularly exhibited diuretic action along with the increase of $E_{Na}$ , $E_{K}$ and $F_{Na}$ , $F_{K}$ by small dose which was not affect on renal function when it given into the vein. Above results suggest that GLY given into the vein in rabbit produce the diuretic action by inhibition of electrolytes reabsorption in renal tubules through central function. function.n. function.ion.

• Journal of Nutrition and Health
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• v.37 no.4
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• pp.291-301
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• 2004

We studied the effects of soy isoflavones supplementation with exercise on bone mineral density and the urinary excretion of deoxypyridinoline as an index of bone resorption rates in postmenopausal women. A total of 67 postmen-opausal women were assigned to Isoflavone (90 mg/day) or placebo groups. These group were further divided into groups that undergone a regular exercise or a rather sedentary state performing daily activity only. Four groups were Placebo-control group (n = 16), Placebo-exercise group (n = 16), Isoflavone-sedentary group (n = 19) and Isofla-vone-exercise group (n = 16). After the intervention, we compared anthropometric mesurement, dietary recall, bone mineral density (femoral neck, lumbar spine), urinary deoxypyridinoline between the groups and between the pre and post studies. There were no significant differences between the four groups in terms of average age, height, weight, period after menopause at the baseline. The average age of the subjects were 55.2 yrs, average height, weight, period after menopause were 154.7 cm, 59.3 kg, 5.58 yrs, respectively. After eight week intervention period, there were no significant differences between the four groups in bone mineral density, but urinary deoxypyridinoline excretion was significantly decreased both in Isoflavone-sedentary and Isoflavone-Exercise groups. These results suggest that Isofla-vone supplementation alone or with exercise may be preventive measures through the decrease of bone reabsorption rate in post-menopausal subjects. Whereas exercise alone did not appear to be an effective measure in bone loss with these subjects.

• Journal of Pharmacopuncture
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• v.10 no.1 s.22
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• pp.23-36
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• 2007

Objective : We performed this study in order to investigate the effects of Paljeongsan-gamibang(八正散加味方) on the renal failure. Methods : We injected 8ml/kg of 50% glycerol on the rats. And then administered Paljeongsan-gamibang extract ; 209mg/200g/day to sample group during 3 days and observed the body temperature, urine volume, stool volume and the levels of creatinine, glucose, inorganic phosphorus, Na+, K+, Cl-, threonine, tyrosine in blood and creatinine, glucose, threonine, tyrosine in urine. Results : 1, The sample group administered Paljeongsan-gamibang showed a suppressive effect of body temperature, an improving effect in capability of concentrating urine at convoluted tubule and showed an increasing effect of stool volume. 2. The sample group administered Paljeongsan-gamibang showed a lowering effect in creatinine level in blood and showed an increasing effect in the levels of inorganic phosphorus, Na+, K+, Cl-, threonine and tyrosine in blood. 3. The sample group administered Paljeongsan-gamibang showed an increasing effect in creatinine level in urine and showed a lowering effect in the levels of glucose, inorganic phosphorus, threonine and tyrosine in urine. Conclusions : Conclusively, Paljeongsan-gamibang was recognized to have a curative effect against the damage of rat kidney induced by 50% glycerol, especially to improve the capability of reabsorption in proximal convoluted tubule.