Influence of Cortical Plasma Transit-Time on p-Aminohippurate Extraction during Induced Renal Vasodilatation in Anaesthetized Dogs

1972 ◽  
Vol 43 (3) ◽  
pp. 401-411 ◽  
Author(s):  
M. T. Velasquez ◽  
A. V. Notargiacomo ◽  
J. N. Cohn
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Transit Time ◽  
Prostaglandin E1 ◽  
Renal Cortex ◽  
Flow Distribution ◽  
Blood Flow Distribution ◽  
Pooled Data ◽  
Intrarenal Blood Flow ◽  
High Degree

1. The influence of intrarenal blood-flow distribution and plasma transit-time through the renal cortex on the reduction in p-aminohippurate (PAH) extraction (EPAH) induced by renal vasodilator agents was evaluated in anaesthetized dogs by an indicator-dilution technique. 2. Increases in renal blood flow during graded intravenous iso-osmotic saline or hyperosmotic mannitol infusions and during renal arterial infusions of acetylcholine or prostaglandin E1 were consistently associated with reduced EPAH. 3. The cortical fraction of renal blood-flow increased during vasodilatation induced by saline or acetylcholine but was unchanged during mannitol or prostaglandin infusions. Cortical blood volume (CBV) increased with saline infusion but was reduced with mannitol. Changes in CBV with acetylcholine and prostaglandin E1 were insignificant. No correlation could be found between changes in EPAH and changes in intrarenal blood flow distribution. 4. A high degree of correlation (r = 0·81) was noted between EPAH and the simultaneously determined mean cortical plasma transit-time. A significant correlation existed with pooled data for all infusions as well as with individual drug infusions. 5. We interpret these data to indicate that a shortened transit-time of plasma through the cortex, indicative of an increased velocity of cortical plasma flow, is the most important determinant of the lowering of EPAH during renal vasodilatation.

Measurement of Intrarenal Blood-Flow Distribution in the Rabbit Using Radioactive Microspheres

1975 ◽  
Vol 48 (1) ◽  
pp. 51-60 ◽  
Author(s):  
D. J. Warren ◽  
J. G. G. Ledingham
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Renal Cortex ◽  
Flow Distribution ◽  
Rabbit Kidney ◽  
Radioactive Microspheres ◽  
Injection Dose ◽  
Intrarenal Blood Flow ◽  
Total Renal Blood Flow

1. Total renal blood flow and its distribution within the renal cortex of the conscious rabbit were studied with radioactive microspheres of 15 and 25 μm diameter. 2. The reliability of the microsphere technique was influenced by microsphere diameter and number (dose). The optimum microsphere diameter for determination of flow distribution in the rabbit kidney was 15 μm and dose 100–150 000 spheres. 3. Spheres of 15 μm nominal diameter were randomly distributed within the renal cortex of adult rabbits. The larger spheres in batches nominally 15 μm in diameter in young rabbits and 25 μm diameter in adult rabbits were preferentially distributed to the superficial cortex. 4. In adult rabbits 15 μm diameter spheres lodged in glomerular capillaries. Larger spheres occasionally lodged in interlobular arteries causing intrarenal haemorrhage. 5. Microspheres of 15 μm caused a decrease in renal clearance of creatinine and of p-aminohippurate when the total injection dose was about 200 000 spheres. These effects were greater when the injection dose was increased to 500 000 spheres. 6. The reduction in total renal blood flow observed with large doses of spheres largely reflected decreased outer cortical flow, as measured by a second injection of spheres, and confirmed by a decrease in p-aminohippurate extraction. 7. The reproducibility of multiple injection studies was limited by these intrarenal effects of microspheres. 8. Total renal blood flow measured in six rabbits in acute experiments by the microsphere technique was 107 ± 12 (mean±sd) ml/min and by p-aminohippurate clearance was 100 ± 10 ml/min. 9. Total renal blood flow in twelve conscious, chronically instrumented rabbits was 125 ± 11 ml/min, of which 92 ± 6 ml/min was distributed to the superficial cortex and 33 ± 4 ml/min to the deep cortex.

EFFECTS OF CHRONIC CYCLOSPORINE ADMINSTRATION ON RENAL BLOOD FLOW AND INTRARENAL BLOOD FLOW DISTRIBUTION

1991 ◽  
Vol 51 (2) ◽  
pp. 503-508 ◽  
Author(s):  
DEBBIE F. YOUNGELMAN ◽  
KIM U. KAHNG ◽  
BROOKE D. ROSEN ◽  
LISA S. DRESNER ◽  
RICHARD B. WAIT
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Flow Distribution ◽  
Blood Flow Distribution ◽  
Intrarenal Blood Flow

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.

Effect of inhibition of peptidase activity on distribution of intrarenal blood flow

1975 ◽  
Vol 228 (3) ◽  
pp. 850-853 ◽  
Author(s):  
MD Bailie ◽  
JA Barbour
Keyword(s):  
Blood Flow ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Renal Blood Flow ◽  
Filtration Rate ◽  
Flow Distribution ◽  
Blood Flow Distribution ◽  
Angiotensin I ◽  
Intrarenal Blood Flow ◽  
Total Renal Blood Flow

Experiments were performed in dogs to determine the effects of the intravenous administration of the dipeptide hydrolase inhibitor SQ 20,881 on renal hemodynamics, intrarenal blood flow distribution, and renal function. Dipeptide hydrolase converts angiotensin I to angiotensin II and inactivates bradykinin. SQ 20,881 causes an inhibition of the vasoconstrictor response after angiotensin I and potentiation of the vasodilatory activity of bradykinin. Total renal blood flow, cortical distribution of blood flow, and glomerular filtration rate were determined. In seven animals administration of SQ 20,881 (1 mg/kg) resulted in a decrease in mean systemic blood pressure of 11 mmHg, an increase in total renal blood flow of 0.71 ml/min per g, and a significant fall in glomerular filtration rate. Fractional blood flow to the superficial cortex decreased and to the juxtamedullary cortex increased. Absolute flow was unchanged in the superficial cortex and increased significantly in the deep cortex. The findings are compatible with reported effects of bradykinin on intrarenal blood flow distribution, although the experiments do not distinguish between potentiation of bradykinin or inhibition of angiotensin I conversion.

Intrarenal blood flow distribution during adenosine-mediated vasoconstriction

1983 ◽  
Vol 244 (1) ◽  
pp. H138-H141 ◽  
Author(s):  
J. F. Macias ◽  
M. Fiksen-Olsen ◽  
J. C. Romero ◽  
F. G. Knox
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Late Phase ◽  
Flow Distribution ◽  
Adenosine Infusion ◽  
Blood Flow Distribution ◽  
Intrarenal Blood Flow ◽  
Renal Blood Flow Distribution ◽  
Uniform Reduction ◽  
Intrarenal Distribution

Intrarenal infusion of adenosine induces an initial vasoconstriction followed by a subsequent vasodilation. The intrarenal distribution of blood flow in the vasoconstriction phase is unknown. The present study was undertaken to assess the effect of intrarenal infusion of adenosine on intracortical distribution of renal blood flow during both the vasoconstriction and vasodilation phases. Renal blood flow distribution was measured with radiolabeled microspheres in anesthetized sodium-depleted dogs before and during the early vasoconstriction phase and the late vasodilation phase of intrarenal infusion of adenosine. During the vasoconstriction phase, there was a uniform decrease in blood flow in each renal cortical zone. In the late phase of adenosine infusion, there was a significant increase in deep cortical flow without significant changes in superficial cortical flow compared with control. The effects of adenosine were also compared with those exerted by norepinephrine in which decreased blood flow was demonstrated in all zones. We conclude that the vasoconstrictor phase of adenosine infusion is characterized by a uniform reduction of renal blood flow to all cortical zones, whereas the vasodilator phase is characterized by a selective deep cortical vasodilation.

The Effect of Furosemide on the Intrarenal Blood Flow Distribution in the Dog

1972 ◽  
Vol 50 (8) ◽  
pp. 774-783 ◽  
Author(s):  
Serge Carrière ◽  
Michel Desrosiers ◽  
Jacques Friborg ◽  
Michèle Gagnan Brunette
Keyword(s):  
Blood Flow ◽  
Flow Rate ◽  
Urine Volume ◽  
Flow Distribution ◽  
Blood Flow Rate ◽  
Initial Distribution ◽  
Blood Flow Distribution ◽  
Intrarenal Blood Flow ◽  
Femoral Blood ◽  
Furosemide Administration

Furosemide (40 μg/min) was perfused directly into the renal artery of dogs in whom the femoral blood pressure was reduced (80 mm Hg) by aortic clamping above the renal arteries. This maneuver, which does not influence the intrarenal blood flow distribution, produced significant decreases of the urine volume, natriuresis, Ccreat, and CPAH, and prevented the marked diuresis normally produced by furosemide. Therefore the chances that systemic physiological changes occurred, secondary to large fluid movements, were minimized. In those conditions, however, furosemide produced a significant increase of the urine output and sodium excretion in the experimental kidney whereas Ccreat and CPAH were not affected. The outer cortical blood flow rate (ml/100 g-min) was modified neither by aortic constriction (562 ± 68 versus 569 ± 83) nor by the subsequent administration of furosemide (424 ± 70). The blood flow rate of the outer medulla in these three conditions remained unchanged (147 ± 52 versus 171 ± 44 versus 159 ± 54). The initial distribution of the radioactivity in each compartment remained comparable in the three conditions. In parallel with the results from the krypton-85 disappearance curves, the autoradiograms, silicone rubber casts, and EPAH did not suggest any change in the renal blood flow distribution secondary to furosemide administration.

Measurement of Intrarenal Blood Flow Distribution

1978 ◽  
pp. 41-74 ◽  
Author(s):  
Norbert H. Lameire ◽  
Elaine L. Chuang ◽  
Richard W. Osgood ◽  
Jay H. Stein
Keyword(s):  
Blood Flow ◽  
Flow Distribution ◽  
Blood Flow Distribution ◽  
Intrarenal Blood Flow

scholarly journals Intrarenal Blood Flow Distribution (IRBF) in the Puppy Using Xenon Washout and Microspheres

1970 ◽  
Vol 4 (5) ◽  
pp. 446-446
Author(s):  
Pedro A Jose ◽  
Alexander G Logan ◽  
Gilbert M Eisner ◽  
Lawrence M Slotkoff ◽  
Charles E Hollerman ◽  
...  
Keyword(s):  
Blood Flow ◽  
Flow Distribution ◽  
Blood Flow Distribution ◽  
Intrarenal Blood Flow ◽  
Xenon Washout
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