Comparative renal effects of isoncotic and colloid-free volume expansion in the rat

Daugharty, TM; Ueki, IF; Nicholas, D. Allen; Brenner, B M

doi:10.1152/ajplegacy.1972.222.1.225

Cited by 55 publications

(51 citation statements)

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“…The increase in urinary flow rate may be related to the increase in systemic blood pressure seen during this time. However, changes in filtration fraction and/or intrarenal distribution of blood flow in these animals cannot explain the effects of stress on urine flow and sodium excretion as has been suggested for other situations (7,20).…”

Section: Discussionmentioning

confidence: 83%

Effects of Asphyxia on Renal Function in the Newborn Piglet

et al. 1978

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Summarveter was advanced into the abdominal aorta from the right femoral artery. This catheter was used for the determinatioiof This investigation was undertaken to determine the nature of blood pressure and heart rate and for sampling arterial blood. acute alterations in renal function following the production of Radioactive injections were made through a third h~~o x e m i a , h~~e r c a r b i a , and acidosis in newborn piglets 6-96 catheter (PE-90) placed in the ascending aorta by way of the left hr of age* After com~letion of the procedure piglets carotid artery. The urinary bladder was isolated through a small were allowed to recover from the effects of anesthesia. When midline abdominal incision and catheterizedThe posidead space was increased arterial Oxygen tion of all catheters was confirmed by inspection at the end of decreased whereas arterial carbon dioxide tension and hydrogen the experiment. ion concentration increased. There was little change in glomerAfter suturing the skin incisions all wounds were infiltrated ular fdtration rate. Total renal blood flow decreased and renal with lidocaine. Anesthesia was discontinued and the piglets were increased * 78 mm Hg/ placed upright in a supporting sling and allowed to recover from liter/mm/m2 to 1422 * 504). There was no change in distribu-anesthesia for hr. During the surgical procedure and the tion of intrarenal blood flow. Sodium excretion and urinary flow experiment the piglets were maintained at a body temperature rate demonstrated significant parallel increases following the of 380 using a Merco infant Under these conditions the increase in dead space. Plasma renin concentration increased animals remained calm and undisturbed in the sling, often from 67 to 110 ng/ml.sleeping during the experiment. Rectal temperature was continuously monitored using a Yellow Springs thermister. After Speculation completion of the surgical procedure the piglets were intubated Hypoxia, hypercarbia, and acidosis produced changes in renal with a 3.5 mm Portex endotracheal tube. Baseline determinafunction in newborn piglets. Therapeutic approaches to the tions were made and then a dead space 45 cc/ newborn human with respiratory distress must consider the kg) Was added to the tube in order to produce potential for modifications of renal function which may be hypoxia and hypercarbiadetrimental to the infant.Tritiated methoxy inulin (1 pCi/ml) was infused into the femoral vein at a rate of 0.04 ml/min beginning 1 hr before the onset of the experiment. During each clearance period urine The effects of respiratory distress on cardiopulmonary func-collections were made in preweighed flasks under oil. Urine tion in the newborn infant have been extensively studied. flow rate was estimated from the change in weight without However, renal function during this disease process has not ~0"ection for Specific gravity. Urine Was collected for determibeen adequately described. Recent observations have indicated nation of i n~l i n and sodium and potassium concentration. Artethat newbo...

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Section: Discussionmentioning

confidence: 83%

Effects of Asphyxia on Renal Function in the Newborn Piglet

et al. 1978

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“…After anesthetization with Inactin intraperitoneally (100 mg/kg body weight) the rat was placed on a temperature-regulated micropuncture table and prepared for clearance and/or micropuncture study in the manner previously described for this laboratory (1)(2)(3)(4)(5)(6). In addition to this routine preparation, a loose snare of surgical silk was inserted so as to encircle the left renal artery for subsequent use in reducing blood flow to the left kidney.…”

Section: Methodsmentioning

confidence: 99%

Dynamics of Glomerular Ultrafiltration in the Rat V. RESPONSE TO ISCHEMIC INJURY

Daugharty¹,

Ueki²,

Mercer³

et al. 1974

J. Clin. Invest.

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A B S T R A C T An experimental model of postischemic, acute renal failure has been developed in Wistar rats with surface glomeruli, thereby making possible a direct assessment of the mechanisms responsible for the fall in glomerular filtration rate that characterizes this disorder. Whole kidney and cortical single nephron filtration rates were reduced proportionately, on average by approximately 40%, after 3 h of nearly complete occlusion of the ipsilateral renal artery. The possibility of a significant transtubular leak of inulin was excluded. This decline in filtration rate occurred in the absence of measured changes in mean arterial pressure, mean glomerular transcapillary hydrostatic pressure, or net ultrafiltration pressure at afferent and efferent ends of the glomerular capillary. Net ultrafiltration pressure at the efferent end of the capillary approached zero both before and after ischemic injury, demonstrating that filtration pressure equilibrium was achieved throughout this study. Single nephron filtration fraction remained unchanged, indicating that the fall in filtration rate was accompanied by a proportional decline in glomerular plasma flow. The results indicate that the fall in filtration rate was solely the consequence of this fall in glomerular plasma flow. Since filtration rate per nephron is equal to the product of the ultrafiltration coefficient and mean ultrafiltration pressure, this product must also have fallen in proportion to the decline in glomerular plasma flow. Evidence is presented to indicate that a change in ultrafiltration coefficient is not required to This work has been published in abstract form. 1973. Clin. Res.

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“…There is abundant evidence in the rat to indicate that the natriuresis that attends the acute expansion of extracellular volume with colloid-free solutions is associated with an increase in the rate of delivery of proximal tubule fluid to more distal segments of the nephron, an effect due both to a rise in glomerular filtration rate (GFR)1 and a fall in absolute proximal reabsorption (1)(2)(3)(4)(5). The latter change has been shown to be causally mediated, at least in part, by the accompanying dilutional reduction in postglomerular vascular protein concentration (3).…”

Section: Introductionmentioning

confidence: 99%

“…Immediately upon insertion of the femoral arterial catheter, blood was obtained for repeat determination of hematocrit. Using this and the original (preinfusion) hematocrit, the percentage change in plasma volume was estimated (5). The rate of fluid infusion in chronically loaded rats was unaltered throughout the period of micropuncture and resulted in no consistent change in extracellular volume, as evidenced by the finding that systemic hematocrit changed, on average, by less than 2 vol/100 ml from the period immediately after induction of anesthesia to the point of completion of the experiment.…”

Section: Introductionmentioning

confidence: 99%

Renal Response to Chronic Intravenous Salt Loading in the Rat

Daugharty¹,

Ueki²,

Nicholas³

et al. 1973

J. Clin. Invest.

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A B S T R A C T The natriuresis of acute Ringer's loading is associated with a rise in the rate of delivery of fluid beyond the proximal tubule due both to a rise in glomerular filtration and a fall in absolute reabsorption, the latter being causally mediated, at least in part, by the accompanying fall in postglomerular vascular [protein]. To determine whether these factors also contribute to the renal response to chronic Ringer's loading, nine rats given continuous infusions, 30% body weight/ day over 5-14 days, were studied using free-flow micropuncture techniques. Results were compared with data from 10 chronic control rats given less than 1.5% body wt/day. Late proximal tubule fluid-to-plasma [inulin] ratios, (TF/P) IN, single nephron glomerular filtration rate (SNGFR), absolute proximal reabsorption, and postglomerular vascular [protein] in chronic control rats and chronically loaded rats averaged 2.2± SE 0.1 (n=35) and 1.5±0 (35), P<0.001; 37+-2 (35) and 47±4 nl/min (35), P < 0.05; 19±1 (35) and 16±2 nl/min (35), P > 0.2; and 9.5±0.3 (8) and 8.6±0.3 g/100 ml (8), P > 0.05, respectively. Thus the fall in (TF/P)IN and the rise in distal delivery during chronic Ringer's loading were due almost entirely to the rise in SNGFR, and not to any large fall in absolute reabsorption. Hence chronic and acute Ringer's loading increase delivery of proximal tubule fluid by different mechanisms, with chronic sodium homeostasis being governed overwhelmingly by adjustments in GFR.

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Comparative renal effects of isoncotic and colloid-free volume expansion in the rat

Cited by 55 publications

References 0 publications

Effects of Asphyxia on Renal Function in the Newborn Piglet

Effects of Asphyxia on Renal Function in the Newborn Piglet

Dynamics of Glomerular Ultrafiltration in the Rat V. RESPONSE TO ISCHEMIC INJURY

Renal Response to Chronic Intravenous Salt Loading in the Rat

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