scholarly journals Phosphorus Localization and Its Involvement in the Formation of Concentrated Uranium in the Renal Proximal Tubules of Rats Exposed to Uranyl Acetate

2019 ◽  
Vol 20 (19) ◽  
pp. 4677 ◽  
Author(s):  
Homma-Takeda ◽  
Numako ◽  
Kitahara ◽  
Yoshida ◽  
Oikawa ◽  
...  

Although the kidneys comprise a critical target of uranium exposure, the dynamics of renal uranium distribution have remained obscure. Uranium is considered to function physiologically in the form of uranyl ions that have high affinity for phosphate groups. The present study applied microbeam-based elemental analysis to precisely determine the distribution of phosphorus and uranium in the kidneys of male Wistar rats exposed to uranium. One day after a single subcutaneous injection of uranyl acetate (2 mg/kg), areas of concentrated phosphorus were scattered in the S3 segments of the proximal tubule of the kidneys, whereas the S3 segments in control rats and in rats given a lower dose of uranium (0.5 mg/kg) contained phosphorus without concentrated phosphorus. Areas with concentrated phosphorus contained uranium 4- to 14-fold more than the mean uranium concentration (126–472 vs. 33.1 ± 4.6 μg/g). The chemical form of uranium in the concentrated phosphorus examined by XAFS was uranium (VI), suggesting that the interaction of uranyl ions with the phosphate groups of biomolecules could be involved in the formation of uranium concentration in the proximal tubules of kidneys in rats exposed to uranium.

2020 ◽  
Vol 1 (1) ◽  
pp. 33
Author(s):  
Wenni Juniarni Tripani ◽  
Muhammad In’am Ilmiawan ◽  
Willy Handoko

Background: Physical exercise aims to improve or maintain physical fitness. However, excessive physical exercise may cause increase of oxidative stress which leads to cellular injury, including in the proximal tubules of kidney. This research aims to find out the effect of single- and repeated- excessive swimming exercise to the kidney histopathology of male wistar rats (Rattus norvegicus). Methods: This research was an experimental study with complete random and post test only control group design. Twenty seven male wistar rats were divided into three treatment groups: control group, single- excessive swimming exercise group (45 minutes for one day), and repeated- excessive swimming exercise group (45 minutes/day for seven days). In the end of the treatment, the kidney of the rats were taken to be analyzed by using hematoxylin-eosin stain. The mean of proximal tubules injury of kidneys were counted by two observers using blinded method. Data were analyzed by using one way anova test. Result: The analysis showed there was a significant difference in the mean percentage of proximal tubules injury between control group and single swimming group as well as the repeated swimming group (Anova p=0,000), also there was significant difference between the treatment groups (p=0,020). The highest average of proximal tubules injury was in the single swimming group. Conclusion: Single- and repeated- excessive swimming exercise causes the proximal tubules injury of kidney.


1989 ◽  
Vol 256 (6) ◽  
pp. H1747-H1751 ◽  
Author(s):  
Y. Ouchi ◽  
S. Kim ◽  
A. C. Souza ◽  
S. Iijima ◽  
A. Hattori ◽  
...  

This study was conducted to investigate the effect of intracerebroventricular administration of endothelin (EDT), a novel potent vasoconstricting peptide, on blood pressure in conscious rats. The lateral cerebral ventricle of male Wistar rats was cannulated, and the femoral artery was also cannulated to measure the mean arterial blood pressure (MABP) and heart rate (HR). EDT dissolved in 10 microliters of artificial cerebrospinal fluid (ACSF) (8.25-66 pmol icv) provoked a dose-dependent increase in MABP. EDT also increased HR, although the effect of 66 pmol was variable. Intracerebroventricular ACSF did not provoke any effects on MABP and HR. Intracerebroventricular EDT also provoked contralateral rotational behavior. Pretreatment with 2 mg/kg iv phenoxybenzamine significantly suppressed the 16.5 pmol icv EDT-induced increase in MABP. Moreover, 16.5 pmol icv EDT markedly increased plasma epinephrine and norepinephrine concentration. These results indicate that EDT has a central pressor action, and the action might be mediated, at least in part, by catecholamine release to the periphery. EDT might play a role in the central control of blood pressure, although the physiological implications have not yet been determined.


1988 ◽  
Vol 22 (2) ◽  
pp. 122-126 ◽  
Author(s):  
H. L. Bartels ◽  
B. van der Lei

130 Male Wistar rats, 2-3 months old and weighing 250-350 g were operated on to implant biodegradable small-calibre vascular prostheses (length 10 mm; internal diameter 1-5 mm) in their infrarenal abdominal aorta. The mean operation time was 40 min, the mean aortic cross-clamping time 25 min. The early patency rate was 100% the late patency rate was 97-7%, and the operative mortality was 3-1%. Microscopical examination of the biodegradable prostheses from 1 h up to 1 year after implantation demonstrated reproducable morphological results; in these prostheses a new arterial wall regenerated which had a structure very similar to the normal arterial wall. It was concluded that the rat is an appropriate experimental laboralory animal for testing new types of small-calibre vascular prostheses.


1980 ◽  
Vol 26 (5) ◽  
pp. 562-567 ◽  
Author(s):  
R Bouillon ◽  
P De Moor ◽  
E G Baggiolini ◽  
M R Uskokovic

Abstract We describe a radioimmunoassay for 1,25-dihydroxycholecalciferol in human serum. We raised antisera in rabbits to 1,25-dihydroxycholecalciferol-3-hemisuccinate coupled to bovine serum albumin, and obtained sensitive, high-titer antibodies. These antibodies had a high affinity for 1,25-dihydroxycholecalciferol and cross reacted mainly with 25-hydroxycholecalciferol and 24,25-dihydroxycholecalciferol. Addition of 1 mL of normal rabbit serum per liter reduced this interference to 5 and 4%, respectively. However, these interfering steroids are present in large excess, so extensive purification of 1,25-dihydroxycholecalciferol from serum is necessary. The steroid was extracted with ethyl acetate/cyclohexane, purified on Sephadex LH-20, and then chromatographed on a column of silicic acid. The radioimmunoassay is sensitive to 5 pg/tube (3 ng/L of serum). The between-assay CV was 14%. The mean concentration of 1,25-dihydroxycholecalciferol in the serum of 54 healthy adults was 38 (SD 12) ng/L, with no sex-related difference. The assay was further validated by the finding of low or undetectable concentrations in patients with chronic renal failure and of increased concentrations in the serum of patients with primary hyperparathyroidism. In comparison with previously described methods, the major advantage of the present assay is the use of stable gamma-globulins, which are available in large amounts, as binding protein.


1987 ◽  
Vol 252 (2) ◽  
pp. F226-F231 ◽  
Author(s):  
J. J. Walker ◽  
T. S. Yan ◽  
G. A. Quamme

Renal brush-border membrane phosphate transport was studied in early and late segments of the pig proximal tubule. Vesicles were prepared from early proximal tubules (outer cortical tissue) and late proximal tubules (outer medullary tissue). Sodium-dependent phosphate uptake into brush-border membrane vesicles was determined using voltage clamp at 5-6 s, 21 degrees C. Sodium-dependent D-glucose uptake was determined to verify the cortical and medullary tissue cuts. At pH 8.0 (pHi = pHo), two sodium-dependent phosphate transport systems were evident in the early proximal tubule: a high-affinity system [Km, 0.06 +/- 0.01 mM; maximal transport activity (Vmax), 3.6 +/- 1.1 nmol X mg protein-1 X min-1] and a low-affinity system (Km, 4.11 +/- 0.02 mM; Vmax, 9.7 +/- 0.7 nmol X mg protein-1 X min-1). In the late proximal tubule at pH 8.0, only a single high-affinity transport process (Km, 0.19 +/- 0.7 mM; Vmax, 3.4 +/- 0.5 nmol X mg protein-1 X min-1) was evident. D-Glucose kinetics at pH 7.0 revealed both a high-affinity (Km, 0.55 +/- 0.09 mM) and a low-affinity (Km, 20.09 +/- 1.39 mM) system in the early proximal segment and a single high-affinity (Km, 1.27 +/- 0.36 mM) process in the late segment. These data suggest that two systems, distinct in their affinities and capacities, are involved in both D-glucose and phosphate transport across the brush-border membrane of the early proximal tubule, but that only a single high-affinity system is present in the late segment.


1999 ◽  
Vol 45 (6) ◽  
pp. 807-813 ◽  
Author(s):  
Katinka A Schatteman ◽  
Filip J Goossens ◽  
Simon S Scharpé ◽  
Hugo M Neels ◽  
Dirk F Hendriks

Abstract Background: Procarboxypeptidase U (proCPU) is a novel proenzyme found in human plasma. The active form, carboxypeptidase U (CPU; EC 3.4.17.20), retards the rate of fibrinolysis through its ability to cleave C-terminal lysine residues on fibrin partially degraded by plasmin. This reduces the number of high-affinity plasminogen-binding sites on fibrin. Methods: We developed an assay to determine the proCPU concentration in human plasma. The assay involved quantitative conversion of proCPU to active CPU by thrombin-thrombomodulin, a very efficient activator of proCPU, followed by determination of the enzymatic activity of CPU with the substrate hippuryl-l-arginine, using an HPLC-assisted determination of the released hippuric acid. Using this method, we established a reference interval based on 490 healthy individuals. Results: The mean proCPU concentration, determined after activation of the zymogen in diluted plasma and expressed as CPU activity, was 964 U/L, with a SD of 155 U/L. The population showed a gaussian distribution. However, we noticed important differences related to age and the use of hormone preparations. Conclusions: The sensitivity and precision of the method make it suitable for routine clinical determinations and as a reference procedure.


2019 ◽  
Vol 10 (1) ◽  
pp. 73-81
Author(s):  
Faezeh Nemati Karimooy ◽  
Alireza Ebrahimzadeh Bideskan ◽  
Abbas Mohammadi Pour ◽  
Seyed Mahmoud Hoseini

AbstractStanozolol is an anabolic-androgenic steroid which is commonly abused by athletes for improved energy, appearance, and physical size. It has been previously shown to cause changes in behaviour and has various physical effects. Studies have previously been conducted on its neurotoxic effect on the central nervous system (CNS), which are typically psychological in nature. This study was performed to investigate the apoptotic effect of stanozolol on different parts of the rat hippocampus. Sixteen male Wistar rats were divided randomly into two groups (experimental and control). The experimental group received subcutaneous injections of stanozolol (5mg/kg/day) for consecutive 28 days, whereas the control group received saline using the same dosing schedule and administration route. After routine procedures, coronal sections of rat brain were stained with Toluidine blue and TUNEL for pre-apoptotic and apoptotic cell detection, respectively. In order to compare groups, the mean number of TUNEL-positive and pre-apoptotic neurons per unit area were calculated and analysed. Histopathological examination revealed that the mean number of pre-apoptotic and apoptotic neurons in the CA1, CA2, CA3 and DG areas of the hippocampus were significantly increased in the stanozolol treated group. In conclusion, stanozolol abuse may induce pre-apoptotic and apoptotic cell formation in different regions of the hippocampus.


1974 ◽  
Vol 29 (9-10) ◽  
pp. 597-601 ◽  
Author(s):  
K. Hartmut Richter ◽  
Constantin E. Sekeris

Abstract Rat liver chromatin was titrated by poly-ᴅ-lysine of mol.wt. 140,000. Approximately 32% of the phosphate groups of the chromatin were found to react with the polycation. By submitting the chromatin-poly-ᴅ-lysine complex to pronase and DNase I digestion and by further submitting the obtained DNA-lysine complex to hydroxy-apatite-chromatography, "free" DNA was isolated. The mean S-value of this DNA was found to be 10 ± 0 .8 , corresponding to approximately 2100 nucleo­ tide pairs, its renaturation kinetics similar to total DNA. On the basis of these results and on the findings that histone-saturated DNA-histone recombinates are digested with DNase I up to 65% a model of chromatin structure was proposed, taking into account protein covered-and free DNA regions


2016 ◽  
Vol 58 (4) ◽  
pp. 505-510 ◽  
Author(s):  
Ken Miya ◽  
Shonosuke Matsushita ◽  
Kazuyuki Hyodo ◽  
Chiho Tokunaga ◽  
Hiroaki Sakamoto ◽  
...  

Background No non-invasive method of observing renal microcirculation in vivo has been established as yet. Although angiography is considered to be ideally suited for the purpose, conventional X-rays cannot be used to image structures smaller than 100 µm. Purpose To develop a method for visualizing the renal arterioles, glomeruli, and proximal tubules of rats in vivo making use of synchrotron radiation. Material and Methods Male Wistar rats were anesthetized, and a catheter was inserted via laparotomy into the abdominal aorta with its tip placed above the renal arteries. The rats were paralyzed with a neuromuscular blocking agent and mechanically ventilated. An inorganic iodine contrast medium was injected via the catheter. The SR derived X-rays transmitted through the subjects were recorded with a CCD camera. Two-dimensional images with a pixel size of 9 µm were obtained. The exposure time was fixed at 50 ms, with a maximum acquisition rate of three images/s. Results Renal arterioles as small as 18 µm in diameter, glomeruli with an average diameter of 173 ± 21 µm, as well as proximal tubules, were clearly visualized. In addition, glomerular density at the peripheral renal cortex was measurable. Conclusion Rat renal microcirculation could be successfully observed in real-time, without exteriorization of the kidney in this study.


1982 ◽  
Vol 48 (3) ◽  
pp. 467-475 ◽  
Author(s):  
Andrea Caprez ◽  
Susan J. Fairweather-Tait

1. The effect of heat treatment of bran on true zinc absorption was measured using an isotope-dilution technique. A bran-based breakfast cereal (heated to 204° for 40 min during manufacture) was incorporated into a semi-synthetic diet at a level of 180 g/kg, A parallel diet was formulated containing an identical weight of untreated bran from the same source plus other ingredients used to make the cereal.2. Young male Wistar rats (mean weight 80 g) were injected intramuscularly with 65Zn to label body Zn. They were given the heat-treated- and untreated-bran diets for 9 d. During the last 6 d of this period Zn intakes and faecal and urinary Zn were measured in order to calculate apparent Zn retention. True Zn retention was measured by taking into account losses of Zn of endogenous origin (labelled with 65Zn), by measuring faecal and urinary 65Zn taking the mean specific radioactivity of Zn in kidneys and upper small intestine to represent specific radioactivity of endogenous origin.3. Heat treatment of bran removed approximately one-third of the phytate, but this was not enough to improve Zn absorption from the diet. True Zn retention measured by isotope dilution was significantly higher (P < 0.02) than apparent Zn retention measured bv the conventional balance technique.4. The hypothesis that a reduction in particle size of bran would improve mineral availability was tested by feeding coarse and milled bran (100 g/kg diet) in a semi-synthetic diet to rats and measuring true Fe and apparent Zn absorptions. The importance of phytate was also investigated by feedino a diet containing dephytinized bran.5. Male Wistar rats (mean weight 172 g) were given diets containing coarse, milled or dephytinized bran for 9 d. Fe and Zn intakes were measured and faeces and urine collected for Fe and Zn analysis.6. The mean (±SE) particle size of the bran was reduced on milling from 3.5 (± 1.8) to 0.2–0.5 mm. There were no differences in the fraction of Fe retained between the three groups. Particle size had a small effect on Zn retention which was marginally higher in rats on the milled-bran diet (0.126 (± 0.023)) than in those on the coarse-bran diet (0.087 (± 0.012)). Total removal of phytate had a greater effect and apparent Zn retention from the dephytinized-bran diet was significantly higher (0.182 (±0.027), P < 0.01).


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