It is well known that unilateral nephrectomy induces a series of morphological changes in the remaining kidney. These morphological changes called as "compensatory hypertrophy and hyperplasia" are associated with numerous functional changes of the remnant kidney, such as relative increase in the glomerular filtration rate and the renal plasma flow as well as changes in the renal concentrating ability. However, changes in the water and electrolytes excretion following unilateral nephrectomy have not been extensively studied. Hence, this investigation was undertaken to study the excretory pattern of water and electrolytes through the remaining kidney following unilateral nephrectomy. Experiments were carried out in 23 hydropenic dogs, weighing 10~16 kg, of which 5 dogs were used for acute experiments (4 hrs. after nephrectomy) and 18 dogs for chronic experiments (2 weeks, 4 weeks and 6 weeks after nephrectomy). Following intravenous administration of appropriate amounts of inulin and PAH, plasma and urine samples were obtained and were analyzed for the concentration of inulin, PAH, osmolarity, Na, K and urea. In chronic experiments, Animals were allowed to have free access to the food and water during intervals. Four slices of the tissue from papilla to cortex were cut for each kidney. The Na, K, Cl and urea concentrations of the slice were then determined in slice extracts. Also four slices of the kidney cortex were obtained and analyzed for concentration of PAH. Results may be briefly summarized as follows. 1. After unilateral nephrectomy, the weight of the remaining kidney increased about 30 percent in 2-6 Weeks. 2. During 1 hours after unilateral nephrectomy, the glomerular filtration rate (GFR) of the remaining kidney showed no significant changes while the renal plasma flow (RPF) decreased gradually to a level below the control. In chronic experiments, the GFR showed no change after the nephrectomy whereas the RPF showed a 20 percent increased, thus reducing the filtration fraction. 3. During 1 hours after unilateral nephrectomy, the urine osmolarity revealed no significant changes while the fractional excretion of the filtered osmotic substance, water, sodium and potassium were gradually increased, indicating relative impairments of the tubular reabsorption of these substances. 4. During 2.-,6 weeks after unilateral nephrectomy, the renal concentrating ability of the remaining kidney was significantly impaired. The fractional excretion of the filtered water was most markedly increased while the tubular reabsorption of urea was somewhat increased. 4. No significant changes in plasma composition was noted in all animals, indicating that the overall homeostatic mechanism is apparently well maintained even after unilateral nephrectomy, 6. PAH concentration in the slices of renal cortex after unilateral nephrectomy were markedly increased, suggesting that the increase of PAH uptake on the renal cortex is partially attributable to a increase of the tubular mass of remaining kidney. 7. Medullary and papillary Na and Cl concentration was somewhat lower in the chronic experiments, indicating that the renal concenting operation is impaired in unilateral nephrectomized kidney primarily because of corresponding reduction in the medullary osmotic gradient. However, total papillary osmotic concentration at a given urine osmolarity was no significantly changed in before and after unilateral nephrectomy.
Administration, Intravenous ; Animals ; Dogs ; Electrolytes ; Filtration ; Glomerular Filtration Rate ; Hypertrophy ; Inulin ; Kidney ; Kidney Cortex ; Nephrectomy* ; Osmolar Concentration ; Plasma ; Potassium ; Renal Plasma Flow ; Sodium ; Urea ; Water

BACKGROUND/AIMS: Race and ethnicity are important determinants when estimatingglomerular filtration rate (GFR). The Korean coefficients for the isotope dilution mass spectrometry (IDMS) Modification of Diet in Renal Disease (MDRD) Study equations were developed in 2010. However, the coefficients have not been validated. The aim of this study was to validate the performance of the Korean coefficients for the IDMS MDRD Study equations. METHODS: Equation development and validation were performed in separate groups (development group, n = 147 from 2008 to 2009; validation group, n = 125 from 2010 to 2012). We compared the performance of the original IDMS MDRD equations and modified equations with Korean coefficients. Performance was assessed by comparing correlation coefficients, bias, and accuracy between estimated GFR and measured GFR, with systemic inulin clearance using a single injection method. RESULTS: The Korean coefficients for the IDMS MDRD equations developed previously showed good performance in the validation group. The new Korean coefficients for the four- and six-variable IDMS MDRD equations using both the development and validation cohorts were 1.02046 and 0.97300, respectively. No significant difference was detected for the new Korean coefficients, in terms of estimating GFR, between the original and modified IDMS MDRD Study equations. CONCLUSIONS: The modified equations with Korean coefficients for the IDMS MDRD Study equations were not superior to the original equations for estimating GFR. Therefore, we recommend using the original IDMS MDRD Study equation without ethnic adjustment in the Korean population.
Adult ; Aged ; *Asian Continental Ancestry Group ; Biomarkers/blood ; Case-Control Studies ; Chromatography, High Pressure Liquid ; Creatinine/blood ; Female ; *Glomerular Filtration Rate ; Humans ; Indicator Dilution Techniques ; Inulin/administration & dosage/blood ; Kidney/*physiopathology ; Male ; Mass Spectrometry ; Middle Aged ; *Models, Biological ; Oligosaccharides/administration & dosage/blood ; Predictive Value of Tests ; Renal Insufficiency, Chronic/blood/*diagnosis/ethnology/physiopathology ; Reproducibility of Results ; Republic of Korea

Prebiotics modulate microbial composition and ensure a healthy gastrointestinal tract environment that can prevent colon cancer development. These natural dietary compounds are therefore potential chemopreventive agents. Thirty Sprague-Dawley rats (4 months old) were experimentally treated with procarcinogen dimethylhydrazine to induce colon cancer development. The rats were randomly assigned to three groups: a control group (CG), a group treated with dimethylhydrazine (DMH), and a group given DMH and inulin, a prebiotic (DMH+PRE). The effects of inulin on the activities of bacterial glycolytic enzymes, short-chain fatty acids, coliform and lactobacilli counts, cytokine levels, and cyclooxygenase-2 (COX-2) and transcription nuclear factor kappa beta (NFkappaB) immunoreactivity were measured. Inulin significantly decreased coliform counts (p < 0.01), increased lactobacilli counts (p < 0.001), and decreased the activity of beta-glucuronidase (p < 0.01). Butyric and propionic concentrations were decreased in the DMH group. Inulin increased its concentration that had been reduced by DMH. Inulin decreased the numbers of COX-2- and NFkappaB-positive cells in the tunica mucosae and tela submucosae of the colon. The expression of IL-2, TNFalpha, and IL-10 was also diminished. This 28-week study showed that dietary intake of inulin prevents preneoplastic changes and inflammation that promote colon cancer development.
Animals ; Bacterial Proteins/genetics/metabolism ; Colon/enzymology ; Colonic Neoplasms/chemically induced/*drug therapy/metabolism ; Colony Count, Microbial ; Cyclooxygenase 2/genetics/metabolism ; Cytokines/blood/genetics ; Diet ; Dietary Supplements/analysis ; Dimethylhydrazines/toxicity ; Enterobacteriaceae/drug effects/physiology ; Fatty Acids, Volatile/genetics/metabolism ; Female ; Gene Expression Regulation/drug effects ; Inulin/administration & dosage/*metabolism ; Lactobacillaceae/drug effects/physiology ; Male ; NF-kappa B/genetics/metabolism ; Prebiotics/*analysis ; Rats ; Rats, Sprague-Dawley