Effect of albumin on the function of perfused rat kidney

Schurek, H. J.; Alt, J.

doi:10.1152/ajprenal.1981.240.6.f569

Cited by 43 publications

(37 citation statements)

References 25 publications

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“…Although the colloid osmotic pressure was comparable in both experimental perfusion fluids, a higher perfusate flow was necessary with albumin in the perfusion fluid, to maintain the perfusate pressure at approximately 90 mmHg. GFR decreased in the presence of 2% BSA, owing to enhanced oncotic pressure within the glomerulus and peritubular capillaries; this is in agreement with the concept of Starling (Maack 1980;Schurek & Alt 1981).…”

Section: Renal Excretion and Accumulationsupporting

confidence: 87%

Renal Excretion and Accumulation Kinetics of 2-Methylbenzoylglycine in the Isolated Perfused Rat Kidney

Masereeuw

Moons

Rüssel

1996

Journal of Pharmacy and Pharmacology

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The effect of protein binding on kidney function has been studied by investigating the renal accumulation and secretion of the hippurate analogue 2-methylbenzoylglycine in the isolated perfused rat kidney in the absence and presence of bovine serum albumin (BSA), Experiments were performed with either 2-5% pluronic or a combination of 2-2% pluronic and 2% BSA as oncotic agents; a wide concentration range (1-190 fig inL~1) of 2-methylbenzoylglycine was studied. Tubular secretion appeared to be a function of the amount of unbound drug in the perfusate and was best described by a model consisting of a high and low affinity Michaelis-Menten term. Parameters obtained after the analysis^of renal excretion data were maximum transport velocity for the high affinity site (TM iH ) -3 -0 db 2-8 fig min" , Michaelis-Menten constant for tubular transport for the high affinity site (KTfH ) = 0-5 ± 0-8 fig mL , maximum transport velocity for the low affinity site ^, 0 -2503:36 ¿¿g_min~ , and Michaelis-Menten constant for tubular transport for the low affinity site ( K T(l ) = 62 ±17 fig mL-1 . The compound accumulated extensively in kidney tissue, ratios up to 175 times the perfusate concentration were reached. Accumulation data were best analysed by a two-site model similar to the model used to describe renal excretion. Calculated parameters were theoretical maximum capacity of the high affinity site (Rm,h) = 26 ± 23 f i g g~\ affinity constant for renal accumulation at the high affinity site (KaiH ) = 0*2±04 ¿¿gmL" 1, theoretical maximum capacity of the low affinity site (RM<) = 1640± 1100 jug g and affinity constant for renal accumulation at the low affinity site (K a ,l) = 60± 58 fig mL-1 .TThe very high accumulation in kidney tissue could be explained by active tubular uptake, mediated by the secretory mechanisms involved, and dependent on the amount of free drug in the perfusate. This study shows that anionic drugs, subject to active secretion, may reach high concentrations in tubular cells even at low plasma concentrations.

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Section: Renal Excretion and Accumulationsupporting

confidence: 87%

Renal Excretion and Accumulation Kinetics of 2-Methylbenzoylglycine in the Isolated Perfused Rat Kidney

Masereeuw

Moons

Rüssel

1996

Journal of Pharmacy and Pharmacology

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“…A comparison with renal parameters from blood-free perfused kidneys illustrates the advantages of the present model. Blood-free perfused organs display an non-physiologic filtration fraction, and adding of albumin as oncotic agent also does not alter this constellation [30, 31, 32, 33]. …”

Section: Discussionmentioning

confidence: 99%

A Model of Isolated Autologously Hemoperfused Porcine Slaughterhouse Kidneys

Große-Siestrup¹,

Unger²,

Fehrenberg³

et al. 2002

Nephron

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Background: The rapidly evolving field of transplantation research with a focus on ischemic and reperfusion injuries has gained importance since the methodology of organ preservation significantly limits graft survival. Numerous models of isolated perfused kidneys have been established in the past years but limitations such as organ size, perfusate and ethical standards have restricted a widespread research in this area. Methods: A model of hemoperfused isolated porcine slaughterhouse kidneys was established which encompasses the advantages of autologous blood as optimal perfusate and a reduction of animal experiments. Results: The size and geometry of the porcine kidney is more comparable to human conditions and various renal functions, blood parameters and morphology can easily be accessed in the present model. Stable organ function can be maintained over 2 h with an amount of 500–1,000 ml of autologous blood which is metabolically controlled via a dialysis system. Conclusion: In summary, the present model describes a new and economic approach for targeting renal function in transplantation models by combining autologous blood as optimal perfusate with a well-defined organ geometry and function and slaughterhouse animals as a source.

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“…Kidney perfusion was performed in a recycling system according to the technique of Schurek and Alt [24] with minor modifications as described in detail previously [20,22]. In brief, animals were anaesthetized with 150 mg kg 1 thiobutabarbitone (Inactin, Byk Gulden, Konstanz, Germany).…”

Section: Methodsmentioning

confidence: 99%

Role of calcium ions in the pressure control of renin secretion from the kidneys

Scholz

Hamann

et al. 1994

Pfl�gers Arch

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Abstract. In this study we examined the role of calcium ions in the control of renin release by the renal artery pressure. For this purpose renin secretion rates (RSR) were measured in isolated rat kidneys perfused at pressures of 140, 100, 80 and 40 mmHg [19,13,11, 5 kPa) with media containing either 1.5 retool/1 ("normal") or zero calcium concentrations (calcium-free perfusate with 0.5 mmol/1 EGTA). At normal calcium the RSR was inversely related to the renal artery pressure, whereas calcium withdrawal resulted in an almost linear and proportional relationship between RSR and perfusion pressure. As a consequence, RSR at 140 mmHg (19 kPa) with a calcium-free medium was similar to renin release at 40 mmHg (5 kPa) with normal calcium. The nitric oxide (NO) donor sodium nitroprusside (1 t~mol/1) stimulated RSR in a pressure-dependent fashion at a calcium concentration of 1.5 mmol/1. With a calcium-free perfusate, sodium nitroprusside did not restore the inverse pressure dependence of RSR seen with normal calcium but almost doubled the RSR across the whole pressure range. Whilst RSR was significantly reduced by angiotensin II (1 nmol/1) in the range between 40 mmHg and 140mmHg (5-19kPa) with normal calcium, withdrawal of extracellular calcium ions practically abolished the inhibitory action of angiotensin II. Since angiotensin II attenuated RSR especially at low renal perfusion pressure, our results indicate that renin release in this pressure range is still inhibitable by calcium mobilization in renal juxtaglomerular cells. Thus, the enhancement of renin secretion at lower pressures cannot be explained by a decreased sensitivity of renin release towards calcium ions. Instead, our data support the hypothesis that the "baroreceptor" control of renin secretion is maintained through a pressure-related calcium influx mechanism into juxtaglomerular cells which counteracts the stimulatory effect of locally released NO.

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Effect of albumin on the function of perfused rat kidney

Cited by 43 publications

References 25 publications

Renal Excretion and Accumulation Kinetics of 2-Methylbenzoylglycine in the Isolated Perfused Rat Kidney

Renal Excretion and Accumulation Kinetics of 2-Methylbenzoylglycine in the Isolated Perfused Rat Kidney

A Model of Isolated Autologously Hemoperfused Porcine Slaughterhouse Kidneys

Role of calcium ions in the pressure control of renin secretion from the kidneys

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