scholarly journals Effect of Fenoldopam Continuous Infusion on Glomerular Filtration Rate and Fractional Excretion of Sodium in Healthy Dogs

2016 ◽  
Vol 30 (5) ◽  
pp. 1655-1660 ◽  
Author(s):  
K.L. Kelly ◽  
K.J. Drobatz ◽  
J.D. Foster
Keyword(s):  
Glomerular Filtration Rate ◽  
Continuous Infusion ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Fractional Excretion ◽  
Fractional Excretion Of Sodium ◽  
Healthy Dogs

Supersensitivity to norepinephrine in chronically denervated kidneys: evidence for a postsynaptic effect

1987 ◽  
Vol 65 (11) ◽  
pp. 2219-2224 ◽  
Author(s):  
J. Krayacich ◽  
R. L. Kline ◽  
P. F. Mercer
Keyword(s):  
Blood Flow ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Renal Blood Flow ◽  
Sodium Excretion ◽  
Filtration Rate ◽  
Fractional Excretion ◽  
Urine Flow ◽  
Fractional Excretion Of Sodium ◽  
Infusion Of Norepinephrine

Denervation supersensitivity in chronically denervated kidneys increases renal responsiveness to increased plasma levels of norepinephrine. To determine whether this effect is caused by presynaptic (i.e., loss of uptake) or postsynaptic changes, we studied the effect of continuous infusion of norepinephrine (330 ng/min, i.v.) and methoxamine (4 μg/min, i.v.), an α1 adrenergic agonist that is not taken up by nerve terminals, on renal function of innervated and denervated kidneys. Ganglionic blockade was used to eliminate reflex adjustments in the innervated kidney and mean arterial pressure was maintained at preganglionic blockade levels by an infusion of arginine vasopressin. With renal perfusion pressure controlled there was a significantly greater decrease in renal blood flow (−67 ± 9 vs. −33 ± 8%), glomerular filtration rate (−60 ± 9 vs. −7 ± 20%), urine flow (−61 ± 7 vs. −24 ± 11%), sodium excretion (−51 ± 15 vs. −32 ± 21%), and fractional excretion of sodium (−50 ± 9 vs. −25 ± 15%) from the denervated kidneys compared with the innervated kidneys during the infusion of norepinephrine. During the infusion of methoxamine there was a significantly greater decrease from the denervated compared with the innervated kidneys in renal blood flow (−54 ± 10 vs. −30 ± 14%), glomerular filtration rate (−51 ± 11 vs. −19 ± 17%), urine flow (−55 ± 10 vs. −39 ± 10%), sodium excretion (−70 ± 9 vs. −59 ± 11%), and fractional excretion of sodium (−53 ± 10 vs. −41 ± 10%). These results suggest that vascular and tubular supersensitivity to norepinephrine in chronically denervated kidneys is due to postsynaptic changes involving α1-adrenergic receptors.

Unimpaired excretion of an acute salt load in conscious hypoproteinaemic dogs

1988 ◽  
Vol 75 (3) ◽  
pp. 271-276 ◽  
Author(s):  
J. A. Joles ◽  
H. A. Koomans ◽  
P. Boer ◽  
E. J. Dorhout Mees
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Plasma Protein ◽  
Filtration Rate ◽  
Renal Plasma Flow ◽  
Isotonic Saline ◽  
Fractional Excretion ◽  
Sodium Reabsorption ◽  
Filtration Fraction ◽  
Fractional Excretion Of Sodium

1. The role of hypoproteinaemia in the sodium retention seen in conditions such as the nephrotic syndrome is incompletely known. 2. To define the influence of severe hypoproteinaemia on kidney function, we studied the effect of an intravenous infusion of an isotonic saline load (133 mmol of sodium), as 1 litre of Ringer lactate solution, on sodium excretion and renal haemodynamics in conscious dogs before and after reduction of plasma protein from 68 ± 3 to 36 ±2 g/l by repeated plasmapheresis and a low protein diet. 3. During hypoproteinaemia, 2 days after a period of plasmapheresis, glomerular filtration rate and effective renal plasma flow were lower than in the control study. After the sodium load, both rose to values nearly identical with the pre-infusion levels found in normoproteinaemia, the filtration fraction remaining unchanged. This contrasted with the rise in filtration fraction after expansion in normoproteinaemia, where filtration fraction increased from 32 to 39% due to a rise in glomerular filtration rate. 4. After expansion, natriuresis rose to similar levels in normoproteinaemia (0.18 ±0.06 mmol/min) and hypoproteinaemia (0.20 ± 0.06 mmol/min), and increments in fractional excretion of sodium, potassium and chloride were also similar. However, baseline excretion was higher in the hypoproteinaemic dogs due to their overhydrated condition in this period immediately after plasmapheresis. 5. The fractional excretion of lithium, an alleged marker of proximal tubular sodium reabsorption, rose to comparable levels. 6. Hence, both the increase in filtration and decrease in reabsorption of sodium after an isotonic saline load are not affected by severe reduction in plasma protein concentration. Apparently, the pathways to augment natriuresis after acute expansion function normally in hypoproteinaemia.

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.

The effect of vasopressin and oxytocin on glomerular filtration rate in the conscious rat: contribution to the natriuretic response

1994 ◽  
Vol 141 (1) ◽  
pp. 59-67 ◽  
Author(s):  
M L Forsling ◽  
J M Judah ◽  
R J Windle
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Plasma Concentrations ◽  
Fractional Excretion ◽  
Conscious Rat ◽  
Arterial Blood ◽  
Fractional Excretion Of Sodium ◽  
Dose Dependent ◽  
Higher Doses

Abstract Urine flow, sodium excretion, mean arterial blood pressure and glomerular filtration rate (GFR) were detennined in the conscious unrestrained rat infused with hypotonic saline. The effects of vasopressin infused at 24 and 160 pmol/min and oxytocin infused at 30 and 200 pmol/min were determined. The lower doses of each hormone gave plasma concentrations within the physiological range whereas the higher doses produced plasma concentrations equivalent to those seen following dehydration. Vasopressin produced dose-dependent antidiuretic and natriuretic responses. Hormone infused at both rates increased the clearance of sodium, but only the higher dose caused a significant increase in GFR. Fractional excretion of sodium was significantly elevated by both doses. Oxytocin produced dose-dependent diuretic and natriuretic responses. Again both rates of infusion increased the clearance of sodium, but only the higher dose caused a significant increase in GFR. The lower dose caused a significant increase in the fractional excretion of sodium. It appears, therefore, that increases in GFR may have a role in the natriuretic response to both hormones. However, this response can also be seen when GFR remains unchanged. This fact, together with the observed increases in the fractional excretion of sodium, indicates that these hormones have additional tubular actions. Journal of Endocrinology (1994) 141, 59–67

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.

Estimating glomerular filtration rate in healthy dogs using inulin without urine collection

2012 ◽  
Vol 93 (1) ◽  
pp. 398-403 ◽  
Author(s):  
Miki Nishida ◽  
Masami Uechi ◽  
Shota Kono ◽  
Kayoko Harada ◽  
Megumi Fujiwara
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Urine Collection ◽  
Healthy Dogs

Determinants of the Renal Clearance of Exogenous Lithium in a Large Sample of a White Male Working Population

1993 ◽  
Vol 85 (4) ◽  
pp. 479-485 ◽  
Author(s):  
Francesco P. Cappuccio ◽  
Pasquale Strazzullo
Keyword(s):  
Body Mass Index ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Renal Clearance ◽  
Filtration Rate ◽  
Renal Excretion ◽  
Fractional Excretion ◽  
Working Population ◽  
Proximal Tubular ◽  
Sodium Handling

1. The associations between the renal clearance of ingested lithium (used as a marker of renal proximal tubular sodium handling) and a number of biological variables have been investigated in an unselected sample of 592 healthy and untreated white men (aged 21–68 years) under their usual living conditions and drawn from a population at work. 2. Renal excretion of lithium was expressed both as clearance of lithium and as fractional excretion of lithium, i.e. normalized for unit of glomerular filtrate. 3. Clearance of lithium was positively associated with a number of anthropometric variables such as weight (r = 0.215; P <0.001), height (r = 0.212; P <0.001), body mass index (r = 0.122; P <0.01) and body surface area (r = 0.244; P <0.001). However, when expressed as fractional excretion of lithium many of these associations were lost or tended to be negative (weight, r = −0.107, P <0.01; body mass index, r = −0.119, P <0.01), greatly depending on the strong relationship between body size and/or mass and glomerular filtration rate. The associations between clearance of lithium and other renal variables reflected, in part, a spurious association mediated by the common relationship with glomerular filtration rate. However, when expressed as fractional excretion of lithium, only some associations were apparent (fractional excretion of sodium, r = 0.256, P <0.001; fractional excretion of uric acid, r = 0.336; P <0.001), probably indicating some plausible biological relationships. These results were confirmed by analysis of co-variance by quintiles of clearance of lithium and fractional excretion of lithium. 4. The results of the present study show that the renal excretion of ingested lithium (an approximate index of proximal tubular sodium handling in man) could be used in an epidemiological setting. However, the use of the fractional excretion of lithium rather than the clearance of lithium as such would be advisable to remove the confounding effects of age and anthropometry, at least in a white middle-aged male working population.

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

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