Acute study of interaction among cadmium, calcium, and zinc transport along the rat nephron in vivo

2004 ◽  
Vol 287 (5) ◽  
pp. F1067-F1075 ◽  
Author(s):  
O. Barbier ◽  
G. Jacquillet ◽  
M. Tauc ◽  
P. Poujeol ◽  
M. Cougnon
Keyword(s):  
Renal Function ◽  
Filtration Rate ◽  
Loop Of Henle ◽  
Zinc Transport ◽  
Major Site ◽  
Nephron Segments ◽  
Proximal Tubulopathy ◽  
Acute Study ◽  
Microinjection Techniques

This study investigates the effect in rats of acute CdCl2 (5 μM) intoxication on renal function and characterizes the transport of Ca2+, Cd2+, and Zn2+ in the proximal tubule (PT), loop of Henle (LH), and terminal segments of the nephron (DT) using whole kidney clearance and nephron microinjection techniques. Acute Cd2+ injection resulted in renal losses of Na+, K+, Ca2+, Mg2+, PO4−2, and water, but the glomerular filtration rate remained stable. 45Ca microinjections showed that Ca2+ permeability in the DT was strongly inhibited by Cd2+ (20 μM), Gd3+ (100 μM), and La3+ (1 mM), whereas nifedipine (20 μM) had no effect. 109Cd and 65Zn2+ microinjections showed that each segment of nephron was permeable to these metals. In the PT, 95% of injected amounts of 109Cd were taken up. 109Cd fluxes were inhibited by Gd3+ (90 μM), Co2+ (100 μM), and Fe2+ (100 μM) in all nephron segments. Bumetanide (50 μM) only inhibited 109Cd fluxes in LH; Zn2+ (50 and 500 μM) inhibited transport of 109Cd in DT. In conclusion, these results indicate that 1) the renal effects of acute Cd2+ intoxication are suggestive of proximal tubulopathy; 2) Cd2+ inhibits Ca2+ reabsorption possibly through the epithelial Ca2+ channel in the DT, and this blockade could account for the hypercalciuria associated with Cd2+ intoxication; 3) the PT is the major site of Cd2+ reabsorption; 4) the paracellular pathway and DMT1 could be involved in Cd2+ reabsorption along the LH; 5) DMT1 may be one of the major transporters of Cd2+ in the DT; and 6) Zn2+ is taken up along each part of the nephron and its transport in the terminal segments could occur via DMT1.

Cysteine enhances in vivo natriuretic potency of ethacrynic acid in the rat

1990 ◽  
Vol 68 (9) ◽  
pp. 1275-1277 ◽  
Author(s):  
E. Kompanowska-Jezierska ◽  
L. Dobrowolski ◽  
J. Sadowski
Keyword(s):  
Blood Flow ◽  
Intravenous Infusion ◽  
Filtration Rate ◽  
Ethacrynic Acid ◽  
Loop Of Henle ◽  
Nacl Transport ◽  
Excretory Function ◽  
Electrical Admittance ◽  
Renal Excretory Function

Total renal blood flow, glomerular filtration rate, and renal excretory function were determined in anesthetized rats treated with intravenous infusion of ethacrynic acid, 0.36 mg∙min−1∙kg−1, alone or in combination with cysteine. Simultaneously, the corticomedullary electrolyte gradient was evaluated in vivo from measurement of tissue electrical admittance (reciprocal impedance). Renal hemodynamics was not altered by drag infusion. Sodium excretion increased 1.7-fold with ethacrynic acid alone and 5-fold after the addition of cysteine. Tissue electrolytes of inner medulla decreased much more in rats given ethacrynic acid plus cysteine. We conclude that the addition of cysteine to intravenous infusion of ethacrynic acid greatly enhances its in vivo natriuretic potency in the rat.Key words: tubular NaCl transport, loop diuretics, loop of Henle, tissue electrolyte gradient.

scholarly journals Kidney Function and Net Glucose Production in Normal and Acidotic Sheep

1973 ◽  
Vol 26 (6) ◽  
pp. 1389 ◽  
Author(s):  
GH Mcintosh ◽  
O H Filsell ◽  
IG Jarrett
Keyword(s):  
Blood Flow ◽  
Renal Function ◽  
Body Weight ◽  
Glucose Concentration ◽  
Physiological Response ◽  
Filtration Rate ◽  
Glucose Production ◽  
Acid Base ◽  
Major Site ◽  
Acid Base Status

Net glucose production and renal function were assessed simultaneously in normal sheep which were subsequently made acidotic by ammonium chloride administration. Arteriovenous differences in glucose concentration were measured, together with p-aminohippuric acid and inulin clearances in one kidney. In normal sheep there was a small net output of glucose by the kidney [20 Ilg min- 1 (kg body weight)-l] which was increased threefold during acidosis. The increase was associated with an elevated venous-arterial difference in glucose concentration and a fall in renal blood flow, while glomerular filtration rate did not change. The increase in the proportion of blood being filtered indicates that there is a greater perfusion of the active zone of the cortex, which is the major site of glucose production in the kidney. This suggests that changed intrarenal events are associated with the physiological response of the kidney to altered acid-base status. The contribution by the kidneys to the overall glucose requirements in sheep, even during acidosis, is unlikely to be greater than 6%.

Clinical Renal Function Testing by External Double Isotope Monitoring Technique

1971 ◽  
Vol 10 (01) ◽  
pp. 16-24
Author(s):  
J. Fog Pedersen ◽  
M. Fog Pedersen ◽  
Paul Madsen
Keyword(s):  
Renal Function ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Plasma Flow ◽  
Filtration Rate ◽  
Renal Plasma Flow ◽  
Correlation Coefficients ◽  
Feedback System ◽  
Effective Renal Plasma Flow ◽  
Advantages And Disadvantages

SummaryAn accurate catheter-free technique for clinical determination simultaneouslyof glomerular filtration rate and effective renal plasma flow by means of radioisotopes has been developed. The renal function is estimated by the amount of radioisotopes necessary to maintain a constant concentration in the patient’s blood. The infusion pumps are steered by a feedback system, the pumps being automatically turned on when the radiation measured over the patient’s head falls below a certain preset level and turned off when this level is again readied. 131I-iodopyracet was used for the estimation of effective renal plasma flow and125I-iothalamate estimation of the glomerular filtration rate. These clearances were compared to the conventional bladder clearances and good correlation was found between these two clearance methods (correlation coefficients 0.97 and.90 respectively). The advantages and disadvantages of this new clearance technique are discussed.

RENAL FUNCTION AND KIDNEY SIZE FOLLOWING HYPOPHYSECTOMY IN MAN

1965 ◽  
Vol 48 (3) ◽  
pp. 348-354 ◽  
Author(s):  
Thomas Falkheden ◽  
Ingmar Wickbom
Keyword(s):  
Renal Function ◽  
Diabetic Retinopathy ◽  
Glomerular Filtration Rate ◽  
Plasma Flow ◽  
Mammary Carcinoma ◽  
Filtration Rate ◽  
Renal Plasma Flow ◽  
Kidney Weight ◽  
Kidney Size ◽  
Before And After

ABSTRACT Measurements of glomerular filtration rate (GFR) and renal plasma flow (RPF) were performed in close connection with roentgenographic estimation of kidney size, before and after hypophysectomy, in 10 patients (four cases of metastatic mammary carcinoma, five cases of diabetic retinopathy and one case of acromegaly). Hypophysectomy was regularly followed by a decrease in GFR and RPF. In most cases, a reduction in the roentgenographic kidney size was also observed. However, the changes in the roentgenographic kidney size and calculated kidney weight after hypophysectomy were smaller and occurred at a slower rate than the alterations in GFR and RPF. The results favour the view that, primarily, the decrease in GFR and RPF following hypophysectomy is essentially functional rather than due to a reduced kidney mass.

Early Renal Dysfunction in Obese Patients with Insulin Resistance

2019 ◽  
Vol 26 (3) ◽  
pp. 261-265
Author(s):  
Natalia Pertseva ◽  
Mariia Rokutova
Keyword(s):  
Insulin Resistance ◽  
Renal Function ◽  
Renal Dysfunction ◽  
Filtration Rate ◽  
Diagnostic Value ◽  
Glomerular Hyperfiltration ◽  
Model Assessment ◽  
Homa Index ◽  
Obese Patients ◽  
Homeostasis Model Assessment

Abstract Background and aims. Obese individuals have insulin resistance status assessed in the present study by the HOMA index (“Homeostasis model assessment”). This prospective study assessed renal disorders in the insulin resistance in obese patients. Material and Methods. The study included 73 young obese patients. The assessment included the HOMA index before meal and parameters of renal function (glomerular filtration rate, albuminuria, β2-microglobulinuria). Results. In young obese, insulin-resistance patients, glomerular hyperfiltration and β2-microglobulinuria are found in 77.0 and 93.4% of cases respectively. The albuminuria is noted in some cases, which reduces diagnostic value. Conclusions. In young obese patients with insulin resistance, glomerular hyperfiltration and β2-microglobulinuria are main diagnostic markers of renal dysfunction.

STUDY OF RADIATION CHARACTERISTICS THE RENAL FUNCTION IN PATIENTS WITH TYPE 2 DIABETES

2014 ◽  
pp. 73-77
Author(s):  
Van Chuong Nguyen ◽  
Thi Kim Anh Nguyen
Keyword(s):  
Type 2 Diabetes ◽  
Renal Function ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Disease Duration ◽  
Left Kidney ◽  
Cross Sectional ◽  
The Right

Background: A Research glomerular filtration rate (GFR) of 61 patients with type 2 diabetes mellitus with renal scanning 99mTc-DTPA glomerular filtration rate at the hospital 175. Objective: (1) To study characteristics of imaging of renal function. (2) Understanding the relationship between GFR with blood sugar, HbA1c, blood pressure and albuminuria in patients with type 2 diabetes. Methods: Descriptive, prospective, cross-sectional study. Clinical examination, Clinical tests and 99mTc-DTPA GFR gamma - camera renography for patients. Result: GFR of the study group was 75,4 ± 22,3 ml/phut/1,73m2, the left kidney was 35,0 ± 13,0 is lower than the right kidney and 39,8 ± 11,9; p <0,01. There is no correlation between GFR with blood glucose and HbA1c, the risk of reduced GFR in hypertensive group associated is OR = 6,5 with p<0,01; albuminuria (+) is OR = 4,2 with p <0,01; and disease duration > 10 years is OR = 3,5 with p <0.01. Conclusion: GFR of the left kidneys is lower than the right kidney; correlation decreased GFR associated with hypertension, albuminuria and disease duration. Keywords: GFR, diabetes, albuminuria

scholarly journals Assessing glomerular filtration rate in healthy adult potential kidney donors in Bangladesh: A comparison of various prediction equations with measured glomerular filtration rate by diethylentriamine pentaacetic acid renogram

2014 ◽  
Vol 39 (2) ◽  
pp. 74-79
Author(s):  
F Jahan ◽  
MNU Chowdhury ◽  
T Mahbub ◽  
SM Arafat ◽  
S Jahan ◽  
...  
Keyword(s):  
Renal Function ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Healthy Adult ◽  
Healthy Population ◽  
Prediction Equations ◽  
Estimated Gfr ◽  
Kidney Donors ◽  
Measured Gfr

To ensure that potential kidney donors in Bangladesh have no renal impairment, it is extremely important to have accurate methods for evaluating the glomerular filtration rate (GFR). We evaluated the performance of serum creatinine based GFR in healthy adult potential kidney donors in Bangladesh to compare GFR determined by DTPA with that determined by various prediction equations. In this study GFR in 61 healthy adult potential kidney donors were measured with 99mTc-diethylenetriamine penta-acetic acid (DTPA) renogram. We also estimated GFR using a four variable equation modification of diet in renal disease (MDRD), Cockcroft-Gault creatinine clearance (CG CrCl), Cockcroft-Gault glomerular filtration rate (CG-GFR). The mean age of study population was 34.31±9.46 years and out of them 65.6% was male. In this study mean mGFR was 85.4±14.8. Correlation of estimated GFR calculated by CG-CrCl, CG-GFR and MDRD were done with measured GFR DTPA using quartile. Kappa values were also estimated which was found to be 0.104 for (p=0.151), 0.336 for (p=0.001) and 0.125 for (p=0.091) respectively. This indicates there is no association between estimated GFR calculated by CG-CrCl, CG-GFR, MDRD with measured GFR DTPA. These results show poor performance of these equations in evaluation of renal function among healthy population and also raise question regarding validity of these equations for assessment of renal function in chronic kidney disease in our population. DOI: http://dx.doi.org/10.3329/bmrcb.v39i2.19646 Bangladesh Med Res Counc Bull 2013; 39: 74-79

Electrolyte handling by the superficial nephron of the rabbit

1986 ◽  
Vol 250 (4) ◽  
pp. F590-F595 ◽  
Author(s):  
N. L. Wong ◽  
S. J. Whiting ◽  
C. L. Mizgala ◽  
G. A. Quamme
Keyword(s):  
Glomerular Filtration Rate ◽  
Proximal Tubule ◽  
Concentration Ratio ◽  
Filtration Rate ◽  
Distal Tubule ◽  
Mean Value ◽  
Loop Of Henle ◽  
Collection Site ◽  
Micropuncture Study ◽  
The Mean

A micropuncture study of the rabbit was performed to evaluate the function of the superficial nephron. The mean glomerular filtration rate of the left micropunctured kidney was 4.0 +/- 0.8 ml/min. The concentration profile of electrolytes within the proximal tubule was similar to that of species previously investigated except for potassium. The mean tubular fluid (TF)-ultrafilterable (UF) concentration ratios were as follows: sodium, 1.01 +/- 0.03; chloride, 1.14 +/- 0.04; calcium, 1.12 +/- 0.04; magnesium, 1.47 +/- 0.08; and phosphate, 0.94 +/- 0.09, with a mean TF-plasma (P) inulin concentration ratio of 1.78 +/- 0.14 (n = 32). The TF/UF potassium value significantly increased in association with TF/P inulin to a mean value of 1.26 +/- 0.06. Accordingly, 29% of the filtered potassium was reabsorbed in the superficial proximal tubule compared with 43% of the filtered sodium. The loop of Henle reabsorbed 55-60% of the filtered sodium, chloride, and calcium, whereas considerably less magnesium (33%) was reabsorbed. Segments beyond the distal tubule collection site reabsorbed little of the delivered magnesium, which supports the notion that the loop of Henle is the principal segment accounting for adjustments in magnesium balance. These studies indicate that the superficial nephron of the rabbit performs similar to other species reported, except potassium reabsorption is significantly less in the proximal convoluted tubule.

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