Effect of Hypertonic Mannitol on Accumulation Rate and Distribution of Albumin in the Renal Papilla.

This study describes a modified technique to fill the renal vasculature with a silicon rubber (Microfil) compound and obtain morphologic information about the intrarenal distribution of capillary blood flow under a variety of conditions. Kidneys and cremaster muscles of rats were perfused in vivo with Microfil using a perfusion pressure equal to the animal's mean arterial pressure at body temperature. Microfil did not alter arteriolar diameter or the pattern of flow in the microcirculation of the cremaster muscle. The modified protocol reproducibly filled the renal vasculature, including; glomerular, peritubular, and vasa recta capillaries. We compared the filling of the renal circulation in control rats with that seen in animals subjected to maneuvers reported to alter the intrarenal distribution of blood flow. Infusion of angiotensin II , hypotension, volume expansion, and mannitol‐ or furosemide‐induced diuresis redistributed flow between renal cortical and medullary capillaries. The advantage of the current technique is that it provides anatomical information regarding the number, diameter, and branching patterns of capillaries in the postglomerular circulation critical in determining the intrarenal distribution of cortical and medullary blood flow.

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“…This conclusion is consistent with the previous results of Pilkington et al. () and Goldberg and Lilienfield () in dogs treated with mannitol.…”

Section: Discussionsupporting

confidence: 94%

Visualization of the intrarenal distribution of capillary blood flow

Wang

Gonzalez-Fernandez

et al. 2019

Physiol Rep

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“…After injection of radiolabeled albumin, total accumulation in the inner medulla provides a measure of medullary blood flow, provided that there is no rapid washout of albumin from the medulla. The albumin accumulation technique was developed by Lilienfield and coworkers (20)(21)(22) who injected 131 I albumin into the ascending aorta of dogs, tied off the renal pedicle at timed intervals, and quickly froze the kidneys. The authors observed a linear increase in the volume of distribution of albumin up to one minute after injection and determined a papillary plasma flow rate of 0.25 ml min -1 g -1 .…”

Section: Albumin Accumulationmentioning

confidence: 99%

Renal medullary microcirculation

Pallone

Robertson

Jamison

1990

Physiological Reviews

158

136

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“…assuming a capillary hematocrit of 25% [ 14). The corresponding value for the dog is 0.27-0.31 ml • min"1 • g"1 kw' [15,16,17], These control values are considerably lower compared with other methods.…”

Section: Albumin Accumulationmentioning

confidence: 88%

Evaluation of Methods for Estimating Renal Medullary Blood Flow

Hansell¹

1992

Kidney Blood Press Res

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Although only 10-15% of renal blood flow enters the medulla, renal medullary hemodynamics have been implicated as a key factor for the ability of the kidney to excrete concentrated or diluted urine and to be involved in sodium homeostasis. Due to the obvious importance of medullary hemodynamics, several methods have been developed or modified for estimating regional renal blood flow. The aim of the present paper is to evaluate critically the most commonly used methods available today. Those which are considered in this paper are: (1) albumin accumulation (Lilienfield), (2) rubidium-86 uptake, (3) transit time-indicator dilution, (4) red cell velocity tracking, (5) red cell flux (fluorescently labeled red cells) and (6) laser-Doppler flowmetry. Depending on the method of choice, the reported control values for renal medullary blood flow differ up to tenfold. Overall, it appears that the discrepancies in values obtained from the different methods will not be resolved until the methods are compared directly in the same animal and during different experimental conditions. Furthermore, one needs to understand and describe accurately the involved errors so that proper corrections can be made. It seems likely, however, that the majority of the techniques can be used to study relative changes, but attempts should not be made to draw conclusions about the absolute flow value. In this regard the laser-Doppler method seems to be superior in its simplicity of use and its large advantage of continuous and relatively noninvasive measurement.

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Effect of Hypertonic Mannitol on Accumulation Rate and Distribution of Albumin in the Renal Papilla.

Cited by 10 publications

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Visualization of the intrarenal distribution of capillary blood flow

Visualization of the intrarenal distribution of capillary blood flow

Renal medullary microcirculation

Evaluation of Methods for Estimating Renal Medullary Blood Flow

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