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Biomedical subjects

J Sudo

Publications and source records attributed to J Sudo.

At least 37 records · Page 2Linked to original sources
PubMed1989

Relieving effect of saline on cephaloridine nephrotoxicity in rats.

To elucidate the mechanism(s) of the relieving effect of saline on cephaloridine (CER) nephrotoxicity, rats were given CER in equal quantity (1 g/kg body weight; i.v.), but at two different concentrations (4 and 25%) in saline. Urinary excretion of glucose, which was investigated as an index for renal proximal tubular injury, revealed that the renal damage was less in the 4% CER 25 ml/kg group than in the 25% CER 4 ml/kg group. As to urinary excretions of CER, sodium, potassium and water, no significant differences were observed between the two groups in the first 2 h, but chloride in the 4% CER 25 ml/kg group showed higher values than in the 25% CER 4 ml/kg group. Plasma concentrations of sodium, potassium, chloride and CER, did not show any definite distinctions between the two groups. At the time-point of 20 min after the CER administration, renal CER content was significantly lower in the 4% CER 25 ml/kg group than in the 25% CER 4 ml/kg group. These results suggest that the sodium ion which is needed for cellular trapping of CER is competitively expended for cellular entry of the chloride ion in the kidney, and that the relieving effect of the saline on CER nephrotoxicity is ascribable to the loaded quantity of chloride ion.

Animals↗
PubMed1989

Changes in lipid peroxidation and activities of xanthine oxidase, superoxide dismutase and catalase in kidneys of cephaloridine-administered rats.

To elucidate the toxic and protective mechanisms responsible for cephaloridine (CER)-induced nephrotoxicity, changes in renal formation of malondialdehyde and renal activities of xanthine oxidase, superoxide dismutase and catalase were mainly investigated for 15 days in rats that received single intravenous injections of CER in doses of 100 and 1,000 mg/kg body weight. In the 100 mg/kg group, the above items determined remained within the control levels. In the 1,000 mg/kg group, renal formation of malondialdehyde was observed to be accelerated with the following two stages: highly in the early stage (the 3rd hour to the 2nd day, especially at the 3rd hour) and more highly in the late stage (the 2nd to the 7th day). Concerning the other items determined, significantly different changes were hardly observed in the 1,000 mg/kg group within the 12th hour of the early stage, while the rises in renal activities of xanthine oxidase and falls in renal activities of superoxide dismutase and catalase were observed in the late stage. These results suggested that the increment in malondialdehyde formation in the late stage might be explained enzymatically by both the rises in the activities of xanthine oxidase and the declines in the activities of superoxide dismutase and catalase and that those in the early stage did not relate directly to the above renal enzymatic systems.

Animals↗
PubMed1989

Changes in glutathione peroxidase system and pyridine nucleotide phosphate levels in kidneys of cephaloridine-administered rats.

To elucidate the nephrotoxic mechanisms of cephaloridine (CER), changes in renal contents of glutathione (GSH), glutathione disulfide (GSSG), reduced and oxidized nicotinamide adenine dinucleotide phosphates (NADPH and NADP) and changes in renal activities of glutathione peroxidase, glutathione reductase and glucose-6-phosphate dehydrogenase were examined for 15 days in rats that received single intravenous injections of CER in doses of 0 (control), 100 and 1,000 mg/kg body weight. Significantly different changes from the control group were observed in the 1,000 mg/kg group. The 1,000 mg/kg group showed elevations in renal NADP and NADPH contents and decrements in renal GSH content in the period of the 1st to 3rd hour after the CER-administration. Thus, the fall in renal GSH content was considered to be a cause for renal injury due to the oxygen radicals observed in the early period. After the 6th hour, the 1,000 mg/kg group showed decreases of renal glutathione peroxidase and glutathione reductase activities and increases of renal glucose-6-phosphate dehydrogenase activity as well as GSH content. Although accumulation of GSH in the kidney was clearly observed in the late period, the more highly aggravated renal injury was speculated to be due to the decreased level in the utilization of GSH according to the fall of renal glutathione peroxidase activity.

Animals↗
PubMed1989

Influence of endogenous and exogenous Jaffé-reaction-positive pseudo-creatinine chromogens in determination of creatinine in blood of normal and cephaloridine-administered rats.

To investigate a magnitude of analytic errors brought by certain interfering substances to the chemical method using Jaffé-reaction for determination of creatinine, two sorts of values determined by the chemical method and by the HPLC method were compared between each other, in blood samples obtained from control and cephaloridine (CER)-administered rats. The rats that received an intravenous injection of CER in dose of 1,000 mg/kg body weight, showed two peaks at the 1-hour and on the 3-day. Since the color development of CER determined in the chemical method showed that 1 g of CER corresponded to 0.0208 g of creatinine, the results of plasma CER determination proved that the first peak was ascribable to the color development of CER. As to the second peak, no significant difference was observed between the values of the two methods. This finding denoted that, when the creatinine levels were elevated, the two sorts of values due to the two methods approached to one another, and suggested that the ratio of "endogenous Jaffé-reaction-positive pseudo-creatinine chromogens" to "total Jaffé-reaction-positive chromogens" would be decreased according as the "true" creatinine was increased. In the control rats, the ratio to "total Jaffé-reaction-positive chromogens" was 60% in terms of "true" creatinine, and 40% in terms of "endogenous Jaffé-reaction-positive pseudo-creatinine chromogens."

Animals↗
PubMed1988

Activities of aromatic L-amino acid decarboxylase with L-dopa as substrate in brush-border- and basolateral membranes and cytoplasm obtained from rat renal cortex.

Activities of aromatic L-amino acid decarboxylase (AADC) with L-dopa as its substrate were determined in the plasma membranes and other cellular components isolated from rat renal cortex. The cytoplasm contained a high level of AADC activity, but much lower levels were found in the brush-border- and basolateral membranes. The main site involved in the formation of dopamine from L-dopa was considered to be the cytoplasm, with participation of neither the brush-border- nor the basolateral membranes.

Animals↗
PubMed1988

Reevaluation of analytical procedures on quantitation of urinary protein in rats.

In this study, the original method (Lowry method) of Lowry et al. (1951), its modified method (Lowry-TCA method) with protein precipitation by trichloroacetic acid (TCA) and the new method (BCA method) with bicinchoninic acid reaction, were reexamined as to whether these three methods were applicable to urinary protein quantitation of rats. Because of the presence of the urinary interfering substances, the quantitations in the Lowry- and BCA methods were found to be overestimated more than 3 times as large as in the Lowry-TCA method. When the urine sample was dialyzed against water and determined by the Lowry- and BCA methods, more than 24 hours were found to be needed in order to completely exclude the interfering substances from the urine. From these findings, the Lowry-TCA method is recommended for quantitation of urinary protein in rats.

Animals↗
PubMed1988

Time-dependent changes in plasma levels of cationic electrolytes produced by hypertonic solutions of low potent substance intraperitoneally administered to rats.

In order to investigate interrelations of plasma levels of potassium with those of the other electrolytes in case of intraperitoneal administration of hypertonic solution consisting of low potent substance, each of the three hypertonic solutions (2,800 mOsm/L), i.e., 50% glucose, 8.12% sodium chloride, and 13.16% sodium sulphate, was intraperitoneally injected to rats in a dose of 3.5 ml/kg body weight. Blood was sampled from the femoral artery at 0, 5, 10, 20, 30 and 45 min after the administration and at the time-point of death. In all cases of the three administered groups, the plasma levels of magnesium was observed to start increasing from 5 min, and, then, the potassium levels from 10 min. The phosphorus levels did not show a significant increase until 20 min, showing later an abrupt increase until the death. Calcium, on the other hand, did not show any significant change in the plasma level until the death. These findings denote that a high osmotic pressure moves first intracellular water and magnesium ion to the outside of the cell, and , with a time delay, intracellular potassium ion is forced to move slowly to the outside. Finally, intracellular phosphorus seems to be released into the extracellular space as a result of damages by suppression of mitochondrial oxidative phosphorylation and by activation of phospholipase both of which were caused directly or indirectly by a critical osmotic force.

Animals↗
PubMed1988

Determination of deoxymononucleotides and deoxynucleosides as a tool for toxicological examination--a trial for conversion of absorbance unit into molar amount in deoxydinucleotide.

Conversion of absorbance unit into molar amount was tried as to deoxydinucleotide. In order to achieve this trial, a reversed-phase high-performance liquid chromatographic method with a linear gradient mode was established for separation and quantification of deoxymononucleotides and deoxynucleosides. Selecting 2'-deoxycytidylyl-(3'-5')-thymidylic (5') acid as an example of deoxydinucleotides, this compound dissolved in water was estimated in absorbance unit at 260 nm, and it was treated by alkaline phosphatase and furthermore by snake venom phosphodiesterase. Based on quantification of the cleaved nucleic acid constituents including 2'-deoxycytidine 5'-monophosphoric acid and thymidine by the above method, the molar amount per 1.000 absorbance unit at 260 nm in the deoxydinucleotide was determined. Thus, the conversion of absorbance unit into molar amount is considered to be applicable to other deoxyoligonucleotides.

Chromatography, High Pressure Liquid↗
PubMed1987

Possible mechanism responsible for allopurinol-nephrotoxicity: lipid peroxidation and systems of producing- and scavenging oxygen radicals.

In order to elucidate toxic and protective mechanisms responsible for allopurinol-induced nephrotoxicity in rats, we investigated changes in plasma creatinine concentration, renal lipid peroxidation, and renal activities of xanthine oxidase, superoxide dismutase and catalase, as enzymatic factors in producing and scavenging oxygen radicals. The rats received subcutaneous injections of allopurinol in a dose of 100 mg/kg body weight, once a day for 3 days. In comparison to the control rats, the following changes were observed in the allopurinol-administered rats: an increase in plasma creatinine concentration, increases in renal contents of malonaldehyde, hypoxanthine and xanthine, and an increase of renal activity of xanthine oxidase, and decreases in renal activities of superoxide dismutase and catalase. Peaks in these changes were observed coincidentally on the third day after the administration of the drug was started. Afterwards, these parameters all returned to the control levels. These results strongly suggested that the allopurinol nephrotoxicity was attributed to the increase of lipid peroxidation which had been caused both by an increase in the ability of producing the oxygen radicals and by a decrease in the ability of scavenging the radicals.

Allopurinol↗
PubMed1987

Comparative study of colorimetric method using diazotization reaction and high-performance liquid chromatographic method in determination of para-aminohippuric acid.

In this study, colorimetric method and high-performance liquid chromatographic (HPLC) method were improved and established, respectively, in order to minimize analytical errors in determination of para-aminohippuric acid (PAH) in rat urine and plasma. In terms of the colorimetric method, an operative step following addition of Tsuda reagent was modified as follows: after the addition of Tsuda reagent, reaction mixture was kept at 40 degrees C for 70 min before spectrophotometry. Linearities were observed both in the higher range of 0 and 2.5 to 12.5 micrograms and in the lower range of 0 and 100 to 1,000 ng per test tube, and its practical detection limit was 100 ng per test tube. In terms of HPLC method, using a reversed-phase column (Nucleosil 5 C18), PAH was separated by a mobile phase of acetonitrile/50 mM KH2PO4 (pH 2.8) = 9/95. Linearities were observed in the higher range of 0 and 10 ng to 2 micrograms and in the lower range of 0 and 1 to 10 ng per injection, and its practical detection limit was 1 ng per injection. These results denote that the above two methods are applicable to routine PAH determination. In addition, our HPLC method is considered to be applicable to microassay of PAH, because its sensitivity is more sensitive and minimization of volume system is more easily achieved as compared with the colorimetric method.

Aminohippuric Acids↗