Renal blood flow distribution measured by microspheres during isovolemic hematocrit alteration in rats

1980 ◽  
Vol 58 (4) ◽  
pp. 368-372 ◽  
Author(s):  
U. Ackermann ◽  
A. T. Veress ◽  
H. Sonnenberg
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Rat Kidney ◽  
Urine Volume ◽  
Flow Distribution ◽  
Urinary Volume ◽  
Outer Cortex ◽  
Before And After ◽  
Renal Blood Flow Distribution ◽  
Sodium And Potassium

The distribution of 15-μm microspheres was measured in rat kidneys before and after the animals had undergone either isovolemic hematocrit increase or isovolemic hematocrit decrease. Raising the systemic arterial hematocrit from 46 ± 1% (mean ± SEM) to 59 ± 1% caused a significant decrease in the rates of urinary sodium and potassium excretion [Formula: see text], but no significant changes in total renal blood flow (RBF), filtration fraction (FF), outer cortical flow, inner cortical flow, or rate of urinary volume excretion [Formula: see text]. Fractional sodium excretion was also unchanged suggesting that the decreased [Formula: see text] was the result of a decreased glomerular filtration rate (GFR). The measured decrease in GFR was not statistically significant. Lowering the systemic hematocrit from 45 ± 1% to 33 ± 1% caused a significant fall in FF as well as significant increases in the rate of urine volume excretion [Formula: see text], [Formula: see text], and GFR. There was a significant increase in RBF but again no change in the flow distribution between inner and outer cortex. The findings show that hematocrit alterations alone do not immediately lead to a redistribution of blood flow between inner and outer cortex of the rat kidney.

Neonatal changes in renal blood flow distribution in puppies

1975 ◽  
Vol 228 (5) ◽  
pp. 1453-1461 ◽  
Author(s):  
LC Aschinberg ◽  
DI Goldsmith ◽  
H Olbing ◽  
A Spitzer ◽  
Edelmann CM ◽  
...  
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Renal Cortex ◽  
Flow Distribution ◽  
Blood Flow Distribution ◽  
Outer Cortex ◽  
Outer Medulla ◽  
Inner Cortex ◽  
Renal Blood Flow Distribution ◽  
Intrarenal Distribution

The intrarenal distribution of blood flow was studied in 31 newborn mongrel puppies from 18 h to 70 days using xenon washout and krypton autoradiography. Mean renal blood flow increased from 0.39 plus or minus 0.05 ml/g per min (SE) the 1st wk to 2.06 plus or minus 0.12 ml/g per min at 6 wk. During the 1st wk of life renal cortex was perfused homo-geneously at 0.88 plus or minus 0.19 ml/g per min (SE) and accounted for 35 plus or minus 4% of the renal blood flow. During the 2nd wk a narrow, rapidly perfused zone of outer cortex was identified which was perfused at 3.35 plus or minus 0.26 ml/g per min, received 19.53 plus or minus 5.05% of the total renal blood flow, and represented 15 plus or minus 4% of the mass of the total cortex. The inner cortex and outer medulla at this time received 53.40 plus or minus 4.12% of the flow at 1.07 plus or minus 0.08 ml/g per min. Outer cortical flow increased with age reaching adult values by about 6-10 wk when the rapidly perfused area represented 40 plus or minus 8% of the cortex. These changes are parallel to the results of previously reported studies with microspheres in newborn puppies and are compatible with the well established maturational changes noted in neonates of several species. They represent the first gas-washout studies in animals during the first 6 wk of life.

Failure to abolish reactive hyperemia by indomethacin in denervated kidneys of rabbits

1977 ◽  
Vol 233 (2) ◽  
pp. F89-F93
Author(s):  
C. Aizawa ◽  
N. Honda
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Reactive Hyperemia ◽  
Fractional Flow ◽  
Outer Cortex ◽  
Cortical Blood Flow ◽  
Before And After ◽  
Inner Cortex ◽  
Postocclusive Reactive Hyperemia

The effect of indomethacin (10 mg/kg) on the distribution of cortical blood flow during postocclusive reactive hyperemia was evaluated in denervated kidneys of anesthetized rabbits by the radioactive microsphere technique. Renal denervation caused a slight but not significant increase in renal blood flow with no remarkable alteration in the distribution of cortical blood flow. After release of 1-min occlusion of the renal artery, hyperemic responses developed with a fractional flow redistribution toward the inner cortex. The absolute perfusion rate increased in the inner cortex but did not significantly change in the outer cortex. Indomethacin produced a decrease in renal blood flow despite elevated blood pressure. Even in the indomethacin-treated animals, postocclusive reactive hyperemia appeared concomitantly with the fractional flow redistribution to the inner cortex. The percentage repayment by reactive hyperemia of ischemia during the artery clamping was not significantly different before and after indomethacin administration. The findings indicate that indomethacin did not significantly affect the postocclusive vascular response in denervated kidneys of rabbits, thereby giving evidence against the role of prostaglandins as mediators of reactive hyperemia.

Left ventricular cannulation for microsphere estimation of rabbit renal blood flow

1980 ◽  
Vol 238 (5) ◽  
pp. H736-H739 ◽  
Author(s):  
J. Bhattacharya ◽  
L. J. Beilin
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Renal Blood Flow ◽  
Regional Blood Flow ◽  
Flow Distribution ◽  
Left Ventricular ◽  
Blood Flow Distribution ◽  
Per Se ◽  
Conscious Animals ◽  
Renal Blood Flow Distribution

When cannulation of the left ventricle and the left atrium were compared as methods for measuring for measuring renal blood flow distribution with radioactive microspheres in 9 conscious and 6 anesthetized rabbits, there were no differences between the two injection routes. Left ventricular cannulation per se did not affect cardiac output, nor the percentage of the cardiac output supplying the kidneys; but cardiac outputs estimated by thermodilution by injections via this route were up to 10% greater than those from left atrial injection. The advantages of left ventricular cannulation for experiments on regional blood flow distribution in conscious animals are discussed.

Renal blood flow distribution at varying perfusion pressure in the alloperfused dog kidney

1979 ◽  
Vol 382 (1) ◽  
pp. 91-98 ◽  
Author(s):  
Jiří Heller ◽  
Vladislav Horáček ◽  
Jan Kasalický ◽  
V. Harudová ◽  
J. Hollyová ◽  
...  
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Perfusion Pressure ◽  
Flow Distribution ◽  
Blood Flow Distribution ◽  
Dog Kidney ◽  
Renal Blood Flow Distribution
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