Nephron filtration rate in conscious rats recovering from anesthesia

Bonvalet, J. P.; Champion, M.; Wanstok, F; Berjal, G

doi:10.1152/ajprenal.1977.232.4.f329

Cited by 10 publications

(6 citation statements)

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“…Though this plasma repletion method can in no way be said to return the ainimal to "normal", the physiology of filtration and reabsorption is most probably closer to the awake state than has been previously reported in plasma volume contracted, hydropenic animals (11)(12)(13). For instance, the SNGFR of 51.6+1.6 nl/min g KWt after plasma repletion is reasonably close to that found in superficial nephrons of the awake Wistar rat of 48.7+4.5 nl/ilin as determiined by the ferrocyanide infusion technique (27). When the surgically induced plasma volume losses were replaced, a 50% increase in the filtered bicarbonate load resulted in an increase in absolute proximal bicarbonate reabsorptioin of 30%.…”

Section: Isohydric Ecf Expansionsupporting

confidence: 72%

Control of Proximal Bicarbonate Reabsorption in Normal and Acidotic Rats

Cogan¹,

Maddox²,

Lucci³

et al. 1979

J. Clin. Invest.

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A B S T R A C T This free-flow micropuncture study examined the dependence ofbicarbonate reabsorption in the rat superficial proximal convoluted tubule to changes in filtered bicarbonate load, and thereby the contribution of the proximal tubule to the whole kidney's response to such changes. The independent effects of extracellular fluid (ECF) volume expansion and of acidosis on proximal bicarbonate reabsorption were also examined.When the plasma volume contraction incurred by the micropuncture preparatory surgery was corrected by isoncotic plasma infusion (-1.3% body wt), single nephron glomerular filtration rate (SNGFR), and the filtered total CO2 load increased by 50%. Absolute proximal reabsorption oftotal CO2 (measured by microcalorimetry) increased by 30%, from 808+47 during volume contraction to 1,081+57 pmol/min g kidney wt after plasma repletion, as fractional total CO2 reabsorption decreased from 0.90 to 0.77. Aortic constriction in these plasma-repleted rats returned the filtered load and reabsorption of total CO2 to the previous volume contracted levels. In other animals isohydric ECF expansion with plasma (5% body wt) or Ringer's solution (10% body wt), or both, produced no further diminution in fractional proximal total CO2 reabsorption (0.76-0.81).Metabolic acidosis was associated with very high fractional proximal total CO2 reabsorptive rates of 0.82 to 0.91 over a wide range of SNGFR and ECF volumes.Portions ofthis work were presented at the VII International

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Section: Isohydric Ecf Expansionsupporting

confidence: 72%

Control of Proximal Bicarbonate Reabsorption in Normal and Acidotic Rats

Cogan¹,

Maddox²,

Lucci³

et al. 1979

J. Clin. Invest.

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“…Values for SNGFR, as with total kidney GFR, were also higher in euvolemic rats, by about 50% for each quantity, relative to normal hydropenia. Using [14C] ferrocyanide technique, Bonvalet et al [7] have recently reported val ues similar to these for superficial SNGFR in Wistar rats recovering from ether anes thesia.…”

Section: Discussionmentioning

confidence: 61%

Dynamics of Glomerular Ultrafiltration in Euvolemic Munich-Wistar Rats

Ichikawa¹,

Maddox²,

Cogan³

et al. 1978

Kidney Blood Press Res

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After restoring plasma volume to conscious levels, glomerular pressures and flows governing single nephron glomerular filtration rate (SNGFR) were measured in Munich-Wistar rats possessing surface glomeruli accessible to micropuncture. Although the mean glomerular transcapillary hydraulic pressure difference in these euvolemic rats was similar to that observed in hydropenic animals, initial glomerular plasma flow rate and SNGFR were at least 50% higher than in hydropenic rats. Nevertheless, filtration pressure equilibrium was generally achieved in euvolemic rats, as in hydropenic rats. Afferent and efferent arteriolar resistances were found to be lower in euvolemic than hydropenic rats, suggesting more potent vasoconstrictor forces in the latter group.

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“…Furthermore, the values of ERPF and GFR, and the mean arterial blood pressure reported here are similar to those obtained by Malvin and Fusco (1967), who also induced a steady-state saline diuresis in the conscious rat. The GFR obtained here is lower than in those rats which had just recovered from ether anaesthesia and surgery (Keeler 1974;Bonvalet et al 1977). Furthermore, Thomsen and Olesen (1981) indicated that awake unoperated and awake catheterized Wistar rats showed almost identical urine flows and clearances of sodium and lithium.…”

Section: Discussionmentioning

confidence: 50%

The Effect of Althesin, Ketamine or Pentothal on Renal Function in Saline Loaded Rats

Chen

Chapman

Munday

1985

Clin Exp Pharma Physio

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Rats were prepared with chronic cannulae in the carotid artery, jugular vein and urinary bladder; they were then kept 2 days to allow recovery from surgery. A steady-state continuous saline diuresis was established, then various anaesthetic agents were injected and changes in the urine flow, sodium and potassium excretion rates, GFR, ERPF, ERBF and blood pressure were measured. Five groups of rats were studied: (1) control animals given saline in place of any anaesthetic agent, all parameters measured remained constant; (2) althesin (1.2 mg/kg), all parameters remained constant except for the blood pressure which decreased slightly for 5 min; (3) althesin (12 mg/kg); (4) ketamine (50 mg/kg); (5) pentothal (50 mg/kg). The above anaesthetics altered all of the measured parameters except urine output. Various mechanisms for these anaesthetic agents are discussed. In althesin anaesthetized rats, all the retarded renal parameters recovered within 30 min. It is concluded that for the study of renal function, if a brief anaesthesia is needed, althesin is a more suitable anaesthetic agent.

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Nephron filtration rate in conscious rats recovering from anesthesia

Cited by 10 publications

References 0 publications

Control of Proximal Bicarbonate Reabsorption in Normal and Acidotic Rats

Control of Proximal Bicarbonate Reabsorption in Normal and Acidotic Rats

Dynamics of Glomerular Ultrafiltration in Euvolemic Munich-Wistar Rats

The Effect of Althesin, Ketamine or Pentothal on Renal Function in Saline Loaded Rats

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