Micropuncture study of avian kidney: effect of prolactin

1992 ◽  
Vol 262 (5) ◽  
pp. R933-R937 ◽  
Author(s):  
J. R. Roberts ◽  
W. H. Dantzler
Keyword(s):  
Renal Function ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Fractional Excretion ◽  
Slight Reduction ◽  
Plasma Parameters ◽  
Single Nephron ◽  
Ovine Prolactin ◽  
Fractional Excretion Of Phosphate

Renal function was studied in anesthetized European starlings (Sturnis vulgaris) by micropuncture and clearance techniques. A previous study had shown some changes in the renal function of birds in molt. Endogenous prolactin levels have been shown to be elevated at this time. In the present study, renal function was studied during the infusion of an isotonic sodium chloride solution and then when ovine prolactin was added to the infusion. Ovine prolactin resulted in an elevation of plasma urate concentration but had no significant effects on other plasma parameters or on the concentration of the various ions in tubular fluid samples. Urine flow rate was significantly higher during prolactin infusion, although whole animal glomerular filtration rate, single nephron glomerular filtration rate, and the percentage fluid reabsorption in the proximal tubule (up to the point of micropuncture) were unaltered. The whole animal fractional excretions of sodium and chloride were significantly higher, those of magnesium and potassium were significantly lower, and the fractional excretion of phosphate tended to be lower during prolactin infusion. At the level of the proximal tubules of the reptilian-type nephrons, prolactin infusion caused a slight reduction in the net reabsorption of sodium and chloride. Therefore the main effects of prolactin on renal function are occurring in the distal nephron of the reptilian-type nephrons or in the mammalian-type nephrons. It appears that prolactin may affect renal function in avian species and that these actions may be modulated by a range of factors as has been demonstrated in mammals.

scholarly journals Observations on some renal function indices in dogs under ketamine-xylazine anaesthesia

2014 ◽  
Vol 12 (2) ◽  
pp. 47-51
Author(s):  
ES Ajibola ◽  
SA Rahman ◽  
KT Biobaku ◽  
N Okwelum ◽  
JA Oyewusi ◽  
...  
Keyword(s):  
Renal Function ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Fractional Excretion ◽  
Sodium Concentration ◽  
Plasma Sodium ◽  
Treatment Groups ◽  
Plasma Sodium Concentration ◽  
Sodium Clearance

This study was done to evaluate the effect of an increased dose of ketamine on some renal function indices of Ketamine−Xylazine anaesthetised dogs. Five adult female mongrel dogs assigned to two different treatment groups in a randomized cross over design were used for this study. Each of the dogs received either 10mg/kg or 20mg/kg ketamine at a week interval. The mean glomerular filtration rate (GFR) of creatinine, absolute and fractional excretion of sodium (UNaV, FENa), urine flow rate (UFR), and plasma sodium clearance were all found to be insignificantly increased in dogs that received the higher dose regime of ketamine. All the dogs in the two treatment groups exhibited levels of glycosuria and hyposthenuria. When plasma sodium concentration of dogs treated with 10mg/kg was correlated with UNaV it was found to be significant and strong (P < 0.05; r =0.86). It was however strong but insignificant with sodium clearance (P>0.05; r = 0.82) and creatinine clearance (P> 0.05; r = 0.39). At 20mg/kg, the UNaV, sodium clearance and glomerular filtration rate all correlated weakly and insignificantly with plasma sodium concentration. The enhanced diuresis and natriuresis observed in the two treatment groups could be attributed to the effect of xylazine on either the alpha-2 adrenoceptor of the brain or those on the tubules of the kidney. These effects of xylazine could not be reversed by attempting to competitively antagonize it with a 100% increase in ketamine dose.Keywords: Diuresis, GFR fractional excretion, Ketamine, Natriuresis, xylazine

Effect of Prolactin on Glomerular Filtration Rate

1978 ◽  
Vol 55 (4) ◽  
pp. 335-339 ◽  
Author(s):  
A. L. Riley ◽  
T. C. Hagen ◽  
J. E. Stefaniak
Keyword(s):  
Blood Flow ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Free Water ◽  
Flow Distribution ◽  
Fractional Excretion ◽  
Free Water Clearance ◽  
Fractional Excretion Of Sodium ◽  
Ovine Prolactin

1. The effect of infusion of ovine prolactin was studied in anaesthetized dogs pretreated with bromocryptine to reduce the release of endogenous prolactin. 2. Prolactin, injected intravenously and also directly into one kidney, resulted in a 12–18% increase in glomerular filtration rate (GFR) by both kidneys. 3. This increased GFR was not associated with any demonstrable changes in whole-kidney blood flow, distribution of intrarenal blood flow, fractional excretion of sodium or osmolar or free-water clearance. 4. We conclude that ovine prolactin produced an increase in GFR not dependent on an increase in whole-kidney plasma flow.

Compensatory renal hypertrophy in dogs: single nephron glomerular filtration rate

1977 ◽  
Vol 55 (1) ◽  
pp. 105-110 ◽  
Author(s):  
Serge Carrière ◽  
Michèle Gagnan-Brunette
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Left Kidney ◽  
Urine Volume ◽  
Free Water ◽  
Fractional Excretion ◽  
Fractional Excretion Of Sodium ◽  
Significant Difference ◽  
Single Nephron

Sodium ferrocyanide was used to measure the intrarenal distribution of single nephron glomerular filtration rate (SNGFR) in remaining kidneys of dogs, 10 d after contralateral nephrectomy. It was first demonstrated that the renal function of both kidneys in situ was comparable. Following right nephrectomy, the urine volume, p-aminohippuric acid clearance, creatine clearance, osmolar clearance, fractional excretion of potassium, and sodium excretion of the left kidney increased. Fractional excretion of sodium, free water clearance, and filtration fraction remained unchanged. Following that 10-d period, left kidney weight exceeded that of the previously removed contralateral kidney by 50%, indicating that most of the compensatory hypertrophy had already occurred. No significant difference in the length of the proximal tubule nor in the diameter of the glomeruli of superficial (SUP) and juxtamedullary (JM) nephrons of either kidney could be demonstrated. Most importantly, the ratio of radioactivity in the SUP/JM nephrons of the residual kidney was comparable with that previously observed in normal dog kidneys. Thus, the increase in total kidney GFR is explained through a proportional increase in the SNGFR of the SUP and JM nephrons.

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.

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

Pathogenesis and Assessment of Renal Function in Patients With Liver Cirrhosis

Folia Medica ◽  
2012 ◽  
Vol 54 (4) ◽  
pp. 5-13 ◽  
Author(s):  
Bilyana H. Teneva
Keyword(s):  
Renal Function ◽  
Liver Cirrhosis ◽  
Glomerular Filtration Rate ◽  
Serum Creatinine ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Serum Markers ◽  
Meld Score ◽  
Kidney Damage ◽  
Early Assessment

Abstract In liver cirrhosis patients awaiting liver transplantation, it is prognostically equally important to assess the renal function before and after transplantation. This is evidenced by the inclusion of serum creatinine in the Model for End-Stage Liver Disease (MELD) score. Most of the causes of renal failure in liver cirrhosis are functional, the acute kidney damage including prerenal azotemia, acute tubular necrosis and hepatorenal syndrome. A major index of the renal function, the glomerular filtration rate (GFR) is determined in a specific way in patients with liver cirrhosis. Clinically, serum creatinine is considered the best indicator of kidney function, although it is rather unreliable when it comes to early assessment of renal dysfunction. Most of the patients with liver cirrhosis have several concomitant conditions, which are the reason for the false low creatinine levels, even in the presence of moderate to severe kidney damage. This also holds for the creatinine clearance and creatinine-based estimation equations for assessment of the glomerular filtration rate (the Cockroft-Gault and MDRD formulas), which overestimate the real glomerular filtration. Clearance of exogenous markers is considered a gold standard, but the methods for their determination are rather costly and hard to apply. Alternative serum markers (e.g., cystatin C) have been used, but they should be better studied in cases of liver cirrhosis assessment.

Abstract 6277: Predictive Value of Estimated Glomerular Filtration Rate for Cardiovascular Events: The Treating to New Targets Study

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
James Shepherd ◽  
Chuan-Chuan Wun ◽  
Daniel J Wilson ◽  
Andrea L Zuckerman
Keyword(s):  
Renal Function ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Cardiovascular Events ◽  
Filtration Rate ◽  
Estimated Glomerular Filtration Rate ◽  
Lipid Lowering ◽  
Final Visit ◽  
The Relationship ◽  
Dose Dependent

We previously demonstrated a dose-dependent improvement in renal function and reduction in cardiovascular risk in TNT with intensive lipid lowering with atorvastatin (ATV) 80 mg vs 10 mg. This post hoc analysis examines the relationship between the observed improvement in estimated glomerular filtration rate (eGFR) and reduction of major cardiovascular events (MCVE). After 8 weeks open-label therapy with ATV 10 mg, 10,001 patients with CHD were randomized to double-blind therapy with either ATV 10 or 80 mg. Patients were followed for a median of 4.9 years for the occurrence of MCVEs (CHD death, nonfatal MI, and stroke). The relationship between change from baseline eGFR (using the MDRD equation) at the final visit prior to a MCVE and the risk of MCVE was assessed using a Cox proportional hazards model adjusting for baseline eGFR and other baseline characteristics. Of 9656 patients with complete renal data, 156 had a MCVE before follow-up eGFR assessment and were excluded. In the remaining 9500 patients, mean baseline eGFR was 65.3 mL/min/1.73 m 2 and mean change from baseline was 4.3 mL/min/1.73 m 2 . This represented a reduction in the risk of MCVE of 2.7% per mL increase in eGFR (HR 0.973, 95% CI 0.967– 0.980, P <0.0001). This association remained significant in patients with eGFR <60 and those with eGFR ≥60 mL/min/1.73 m 2 at baseline, with no significant interaction between eGFR change and baseline renal status ( P =0.98). A 5 mL/min on-treatment improvement in eGFR was associated with a 12.6% reduction in MCVE, while a 5 mL/min reduction was associated with a 14.4% increase in MCVE. Mean change from baseline eGFR was 3.5 mL/min/1.73 m 2 with ATV 10 mg and 5.2 mL/min/1.73 m 2 with ATV 80 mg, representing significant 9.3% and 12.4% reductions in risk, respectively. Analysis of interaction between treatment and eGFR change for prediction of MCVE demonstrated a stronger association between eGFR change and MCVE in the ATV 80 mg treatment group ( P =0.011). Improvement in eGFR was highly associated with a reduction in MCVE, irrespective of baseline renal function. This relationship was dose dependent. Improvement in eGFR may be a biomarker for the response to atorvastatin, and for the stabilization of atherosclerotic cardiovascular disease.

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