Biochemical Characteristics of The Na-alpha-Ketoglutarate Cotransport System in Proximal Convoluted and Straight Tubules of the Rabbit Kidney / 대한신장학회잡지

PURPOSE: alpha-Ketoglutarate (alphaKG), a Krebs cycle intermediate, is extensively used in the kidney as a fuel substrate and as a counter anion for organic acid secretion. It is known to be taken up by the proximal tubule cells via the brush-border as well as basolateral membranes. We explored biochemical characteristics of the brush-border and basolateral alphaKG transport systems in pars convoluta and pars recta of the proximal tubule, respectively. METHODS: Brush-border and basolateral membrane vesicles (BBMV and BLMV) were isolated from rabbit renal outer cortex and outer medulla by Percoll gradient centrifugation. Vesicular uptake of alphaKG was determined by rapid Millipore filtration method using alpha-14[C]KG as a substrate. RESULTS: Both BBMV and BLMV showed a Na-gradient dependent uphill transport of alphaKG. The systems in both membranes were similarly inhibited by Li and activated by Na (Hill coefficient of 1.4). Kinetic analyses indicated that the Na-alphaKG cotransporters in the BBMV had a lower substrate affinity as compared with those in the BLMV. The transport systems in BLMVs showed a similar Km but different Vmax between the outer cortex (Km: 34 uM, Vmax: 3.3 nmol/mg protein/10s) and outer medulla (Km: 37, Vmax: 1.8). On the other hand, the systems in BBMVs were different in both Km and Vmax between the outer cortex (Km: 194, Vmax: 3.3) and outer medulla (Km: 89, Vmax: 1.7). CONCLUSION: The findings suggest that both axial and apical to basolateral heterogeneity of the Na-alphaKG cotransport system in proximal tubules may be due to a physiological adaptation to efficiently utilize alphaKG in the kidney.

Mechanism of Amelioration of Cisplatin Nephrotoxicity by Procaine Treatment in Mice / 대한마취과학회지

BACKGROUND: Procaine binds to DNA and reduces cisplatin nephrotoxicity, but the mechanism is poorly understood. We explored whether procaine amelioration of cisplatin nephrotoxicity was related to down-and/or up-regulation of inflammatory response gene tumor necrosis factor-alpha (TNF-alpha), oxidative stress indicator gene heme oxygenase-1 (HO-1) or cell cycle inhibitor gene p21. METHODS: Cisplatin and procaine were intraperitoneally injected to mice at a single dosage of 16 and 80 mg/kg, respectively. Renal evaluation was performed 72 hours after cisplatin administration. The expression of transcripts and proteins was analyzed using real time RT-PCR and Western blot, respectively. RESULTS: Procaine treatment moderately attenuated necrotic changes of renal proximal tubules and increases in BUN and creatinine concentration by cisplatin administration. Kidney platinum level between the cisplatin (cis) group and the cisplatin + procaine (CisPro) group was not different. Although the level of TNF-alpha mRNA increased 4-fold higher in the Cis group than in the control, this increase was not attenuated by procaine treatment. Gene expression of p21 and HO-1 was elevated 175 and 4-times higher in the Cis group than in the control, respectively. But their expression was no further elevated, rather significantly reduced in the CisPro group compared to the Cis group. Protein abundance of p21 and HO-1 was paralleled by their respective mRNA expression. CONCLUSIONS: Procaine amelioration of cisplatin nephrotoxicity is likely to be achieved through processes other than the regulation of TNF-alpha, HO-1 or p21 gene expression.

Quantification of Endothelin-1 mRNA and Endothelin Receptor B mRNA from Cortex and Inner Medulla of Mouse Kidney Using Real-time RT-PCR / 대한신장학회잡지

BACKGROUND: Endothelin-1 (ET-1) production and ET receptor type B (ETRB) density in the kidney increase along the corticomedullary axis. Northern blot showed that preproET-1 mRNA message was higher in medulla than cortex. ETRB mRNA expression by nested RT-PCR was similar to that of ET-1 mRNA. This study was undertaken to evaluate the renal expression pattern of ET-1 and ETRB mRNAs by Northern blot and nested RT-PCR using a real-time RT-PCR technique. METHODS: The cortex and inner medulla of mouse kidney were dissected out and real-time RT- PCR was performed. Fluorescent ntensity of PCR was recorded using the DNA-intercalating dye SYBR green. Melting curve analysis was utilized for selection of sequence-specific PCR products. For the comparision of relative expression of mRNA in the cortex and inner medulla, Pfaffl's formula (Pfaffl MW: Nucleic Acids Res 29: 2003-2007, 2001) was used. RESULTS: Peak Tms of amplified beta-actin, ET-1 and ETRB genes from inner medulla were 88.2degrees C, 90.5degrees C and 85.5degrees C, respectively. In the cortex, expression of ETRB mRNA was greater on an average by 4.59 cycles (24.59=24 times more abundant) compared to that of ET-1 mRNA. In the inner medulla, ETRB message was 25 times greater than ET-1 message. When ET-1 mRNA expression was compared between cortex and inner medulla the ratio was 3.2, indicating that inner medulla contained three times more ET-1 mRNA than cortex. The expression ratio of cortex to inner medulla of ETRB mRNA was 3.3. CONCLUSION: These results suggest that ET-1 mRNA and ETRB mRNA are more abundantly expressed in medulla than cortex and that the distribution of these mRNAs may be intimately related to that of their respective gene products.

Renal Tubular Acidosis in Cadmium-Intoxicated Rats

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 CdCl2 at a dose of 2 mg Cd/kg/day for 3-4 weeks. In Cd-intoxicated animals, arterial pH, PCO2 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.

Cadmium inhibition of renal endosomal acidification

Chronic exposure to cadmium (Cd) results in an inhibition of protein endocytosis in the renal proximal tubule, leading to proteinuria. In order to gain insight into the mechanism by which Cd impairs the protein endocytosis, we investigated the effect of Cd on the acidification of renal cortical endocytotic vesicles (endosomes). The endosomal acidification was assessed by measuring the pH gradient-dependent fluorescence change, using acridine orange or FITC-dextran as a probe. In renal endosomes isolated from Cd-intoxicated rats, the Vmax of ATP-driven fluorescence quenching (H -ATPase dependent intravesicular acidification) was significantly attenuated with no substantial changes in the apparent Km, indicating that the capacity of acidification was reduced. When endosomes from normal animals were directly exposed to free Cd in vitro, the Vmax was slightly reduced, whereas the Km was markedly increased, implying that the biochemical property of the H -ATPase was altered by Cd. In endosomes exposed to free Cd in vitro, the rate of dissipation of the transmembrane pH gradient after H -ATPase inhibition appeared to be significantly faster compared to that in normal endosomes, indicating that the H -conductance of the membrane was increased by Cd. These results suggest that in long-term Cd-exposed animals, free Cd ions liberated in the proximal tubular cytoplasm by lysosomal degradation of cadmium-metallothionein complex (CdMT) may impair endosomal acidification 1) by reducing the H -ATPase density in the endosomal membrane, 2) by suppressing the intrinsic H -ATPase activity, and 3) possibly by increasing the membrane conductance to H+ ion. Such effects of Cd could be responsible for the alterations of proximal tubular endocytotic activities, protein reabsorption and various transporter distributions observed in Cd-exposed cells and animals.

Phagocytosis and Acid Phosphatase Activity against Candida Albicans in Cultured Rabbit Keratocyte

It has been reported that keratocytes endocytose foreign particles both in vitro and in vivo, suggesting the active participation of keratocytes in corneal wound healing and host defense mechanism. This study was conducted to investigate the phagocytosis of keratocytes against Candida albicans[C.albicans]and the intracellular response after phagocytosis. C.albicans were fixed with glutaraldehyde and then coated with fibronectin. After exposing these C.albicans to the cultured rabbit keratocytes, the phagocytosis of keratocytes against C.albicans was evaluated by light microscope[LM]and transmission electron microscope[TEM], while the intracellular response was evaluated by changes of acid phosphatase activity. Also the study about latex beads was performed at the same time to know even if keratocytes can phagocytose foreign particles, regardless of wheather or not the particles are biodegradable. After Wright staining, phagocytosed latex beads and C.albicans were observed on LM and these were recognized to be surrounded by limiting membranes inside the cytoplasm of keratocytes on TEM. The phagocytic rates of fibronectin-coated were increased to 1.5 times , as compared with that of non-coated group. Acid phosphatase activities were higher in C.albicans-exposed groups than in control[keratocytes cultured without C.albicans or latex beads]during the culture period of 24 hours and they also increased according to culture duration and reached to the plateau after 12 hours. In comparison with non-coated group, fibronectin-coated groups showed a increasing tendency of acid phosphatase activity. These results suggest that keratocytes can phagocytose not only foreign particles but also C.albicans and that fibronectin may act as effective opsonin on phagocytosis, and that keratocytes phagocytosing C.albicans increase acid phosphatase activity to digest engulfed C.albicans when corneal stroma was wounded or inflammed.

Changes in phosphate transporter activity evaluated by phosphonoformic acid binding in cadmium-exposed renal brush-border membranes

Direct exposure of renal tubular brush-border membranes (BBM) to free cadmium (Cd) causes a reduction in phosphate (Pi) transport capacity. Biochemical mechanism of this reduction was investigated in the present study. Renal proximal tubular brush-border membrane vesicles (BBMV) were isolated from rabbit kidney outer cortex by Mg precipitation method. Vesicles were exposed to 50~200 muM CdCl2 for 30 min, then the phosphate transporter activity was determined. The range of Cd concentration employed in this study was comparable to that of the unbound Cd documented in renal cortical tissues of Cd-exposed animals at the time of onset of renal dysfunction. The rate of sodium-dependent phosphate transport (Na+-Pi cotransport) by BBMV was determined by 32P-labeled inorganic phosphate uptake, and the number of Na+/-Pi cotransporters in the BBM was assessed by Pi-protectable 14C-labeled phosphonoformic acid ((14C)PFA) binding. The exposure of BBMV to Cd decreased the Na+-Pi cotransport activity in proportion to the Cd concentration in the preincubation medium, but it showed no apparent effect on the Pi-protectable PFA binding. These results indicate that an interaction of renal BBM with free Cd induces a reduction in Na+-Pi cotransport activity without altering the carrier density in the membrane. This, in turn, suggest that the suppression of phosphate transport capacity (Vmax) observed in Cd-treated renal BBM is due to a reduction in Na+-Pi translocation by existing carriers, possibly by Cd-induced fall in membrane fluidity.

Changes in renal brush-border sodium-dependent transport systems in gentamicin-treated rats

To elucidate the mechanism of gentamicin induced renal dysfunction, renal functions and activities of various proximal tubular transport systems were studied in gentamicin-treated rats (Fisher 344). Gentamicin nephrotoxicity was induced by injecting gentamicin sulfate subcutaneously at a dose of 100 mg/kg cntdot day for 7 days. The gentamicin injection resulted in a marked polyuria, hyposthenuria, proteinuria, glycosuria, aminoaciduria, phosphaturia, natriuresis, and kaliuresis, characteristics of aminoglycoside nephropathy. Such renal functional changes occurred in the face of reduced GFR, thus tubular transport functions appeared to be impaired. The polyuria and hyposthenuria were partly associated with a mild osmotic diuresis, but mostly attributed to a reduction in free water reabsorption. In renal cortical brush-border membrane vesicles isolated from gentamicin-treated rats, the Na+ gradient dependent transport of glucose, alanine, phosphate and succinate was significantly attenuated with no changes in Na+/-independent transport and the membrane permeability to Na+. These results indicate that gentamicin treatment induces a defect in free water reabsorption in the distal nephron and impairs various Na+/-cotransport systems in the proximal tubular brush-border membranes, leading to polyuria, hyposthenuria, and increased urinary excretion of Na+ and other solutes.

A Case of Renal Papillary Necrosis Associated with Diabetes Mellitus / 대한비뇨기과학회지

Renal papillary necrosis is rare. It usually occurs in association with diabetes mellitus, pyelonephritis, urinary tract obstruction, analgesic abuse and sickle cell hemoglobinopathies. The basic pathophysiologic process in renal papillary necrosis appears to be ischemic necrosis. We experienced a case of renal papillary necrosis associated with diabetes mellitus. This 59 years old female was diabetic for 10 years and had persistent pyuria, not controlled with antibiotics. The excretory urography showed nonvisualized left kidney and retrograde pyelography showed multiple irregular filling defect in pelvis and ureter. The nephrectomized kidney showed typical findings of papillary necrosis, grossly and microscopically.

The Results of Prostatectomy :The Use of the Flow Rate Nomogram / 대한비뇨기과학회지

The uroflowmetry was accurate, noninvasive method in the assessment of infravesical obstruction, but it was difficult to differentiate normal from obstructed individuals. The use of the flow rate nomogram appeared to differentiate reliably normal from obstructed individuals. The uroflowmetries using flow rate nomogram which was previously reported by our hospital, were performed on 35 BPH patients, 12 patients preoperatively and postoperatively (Group I) and 23 patients postoperatively only due to preoperative urinary retention (Group 2). The following results were obtained. 1. In group 1, the mean preoperative maximal flow rate was 9.4 (ml/sec) and the mean postoperative maximal flow rate was 15.3 (ml/sec). 2. In group 2, the mean postoperative maximal flow rate was 18.3 (ml/sec) 3. In group 1, nine of twelve patients (75%) were improved in the maximal flow rate. But six of twelve patients (50% ) were improved in the flow rate nomogram. 4. In group 2, fourteen of twenty-three patients (70%) were improved in the flow rate nomogram. In summary, this study shows much difference in the results between maximal flow rate and flow nomogram. So uroflowmetry using flow rate nomogram, we consider, will show more objective result in the evaluation of prostatectomized patient.

Male Flow Rate Nomogram and Clinical Correlation (l) / 대한비뇨기과학회지

The flow rate nomogram was based on 204 flow rate measurements in l65 Korean normal men who ranged in age from 20 to 45 years. Using this nomogram, we tested 10 patients with clinically evident outflow obstruction by flowmetry. In 9 of the maximal flow measurements, the nomogram values were less than minus Z standard deviations. The maximal flow rate value after prostatectomy increased an average 2.41 standard deviations. (p=0.006) The use of flow rate nomogram appears to differentiate reliably normal from obstructed individuals and also is highly useful in the postoperative follow up of urinary outflow obstruction.

A Case of Transverse Testicular Ectopia / 대한비뇨기과학회지

Transverse testicular ectopia is a rare anatomical abnormality in which both gonads migrate toward the same hemiscrotum. Herein we report a case of transverse testicular ectopia in a 4 years old boy with review of literature.

A Case of Posterior Urethral Valve / 대한비뇨기과학회지

Posterior urethral valve is the most common obstructive abnormality in male children affecting both Kidneys and likely arise from maldevelopment of the mesonephric duct. We report a case of posterior urethral valve in 4 year old male child with brief review of literature.

A Case of Adrenal Cyst / 대한비뇨기과학회지

Adrenal cyst is a rare pathologic lesion in all patients which can pose difficult problems in terms of diagnosis and treatment. Most are small and found incidentally on autopsy. We report one case of a large adrenal cyst in a 54-year- old female with review of the literature.

Importance of Urologic Evaluation in Staging Gynecologic Carcinoma / 대한비뇨기과학회지

A clinical observation was male on 1,366 patients of gynecologic carcinoma with I.V.P., cystoscopy and T U.R. bladder biopsy at the Department of Urology, Presbyterian Medical Center, Keimyung University School of Medicine, Daegu, Korea during the period from September 1970 through December 1979. The results were as follows: 1. The most common gynecologic carcinomas were cervical carcinoma, adenocarcinoma (endocervical and endometrial), vaginal carcinoma, ovarian carcinoma, vulvar carcinoma, choriocarcinoma and leiomyosarcoma uteri. 2. Of gynecologic carcinoma patients, abnormal I.V.P. findings were noted in 12.96%, abnormal cystoscopic findings in 7.39% and T.U.R. bladder biopsy was done in 2.64% with positive findings in 47.22%. 3. Of cervical carcinoma, it was classified as follows : stage II b (33.81%). stage II a (30.96%), stage III b(16.07%), stage IV(13.O6%), stage IV(33.33%). stage III a(1.66%) and stage la(1.11%) in order. 4. Of cervical carcinoma, abnormal I.V.P findings were noted in 12.5%(stage I-1. 12%, stage II-5. 99%, stage III-34.82%, stage lV-71.43%) with abnormal cystoscopic findings in 6.8%(stage I-1. 12t, stage II-2. 20%, stage III-17. 89%. stage lV_64.29%). 5. Of cervical carcinoma, T.U.R. bladder biopsy was done in 9 cases of II b with 6 positive fin dings, 14 cases of III b with 4 positive findings and 5 cases of IV with 4 positive findings of gynecologic carcinoma. Therefore, it is emphasized that urologic evaluation including I.V.P. and cystoscopy should be per formed in all gynecologic carcinoma patients before treatment.

Conservative Treatment of Renal Injury / 대한비뇨기과학회지

A clinical observation was made on patients of renal injury at the Department of Urology, Presbyterian Medical Center, Daegu, Korea during the period from September 1970 through December 1978. The results were as follows: 1. Most favorable age was from 10 to 39 years(74%), sex ratio, male to female, was 4.4:1, and increasing trend of renal injury was observed. 2. The most common causes of renal injury were falling accident, kick and blow, traffic accident, and stab injury in order. 3. Renal injury was classified as minor injury(30%), major injury(52%) and shattered kidney with or without pedicle injury(18%). 4. Associated injuries were present in 9 patients. 5. Abnormal findings on D.I.P. were presented in 72% of renal injuries. 6. All minor injuries were treated conservatively, all shattered kidney or pedicle injuries operatively, and all major injuries were managed conservatively, except 30% of major injury in which nephrectomy was performed following failure of conservative treatment. 7. Complication was noted in 28% of conservative treatment and in 29% of operative treatment. 8. Patients manged by emergency surgical treatment had average 8.9 days hospital stay, conservative treatment 9.2 days and those by nephrectomy following failure of conservative treatment had average 24.1 days.