The effect of saline infusion and hemorrhage on glomerular filtration pressure and single nephron filtration rate

1969 ◽  
Vol 310 (3) ◽  
pp. 193-205 ◽  
Author(s):  
K. H. Gertz ◽  
M. Brandis ◽  
G. Braun-Schubert ◽  
J. W. Boylan
Keyword(s):  
Glomerular Filtration ◽  
Filtration Rate ◽  
Saline Infusion ◽  
Nephron Filtration Rate ◽  
Filtration Pressure ◽  
Single Nephron Filtration Rate ◽  
Single Nephron

Measurement of Single Nephron Filtration Rate in the Kidney of the River Lamprey, Lampetra Fluviatilis L

1978 ◽  
Vol 77 (1) ◽  
pp. 57-69 ◽  
Author(s):  
R. J. MORIARTY ◽  
A. G. LOGAN ◽  
J. C. RANKIN
Keyword(s):  
Filtration Rate ◽  
Gel Filtration ◽  
Reference Substance ◽  
Nephron Filtration Rate ◽  
River Lamprey ◽  
Peritubular Capillaries ◽  
Single Nephron Filtration Rate ◽  
Single Nephron ◽  
51Cr Edta ◽  
Renal Clearances

The reliability of [3H]inulin as a reference substance for the measurement of glomerular filtration rate (GFR) in river lampreys was investigated. Simultaneously measured renal clearances of [3H]inulin and [14C]-polyethylene glycol (PEG) were not significantly different. Recoveries of [3H]inulin in the urine following its injection into the proximal tubule and urinary duct averaged 83.5±4.0% (n = 14) and 93.0±4.6% (n = 9) respectively. No evidence was obtained to suggest penetration of the tubular wall by [3H]inulin following its introduction into peritubular capillaries. Gel-filtration of lamprey plasma and urine produced no signs of any significant degradation of the inulin to fructose. [3H]inulin recoveries, though significantly below 100% (P < 0.001), were considered adequate to justify its use after allowing for possible sources of error. A mean single nephron filtration rate (SNGFR) value of 7.02±0.27 nl/min (n = 89) was obtained from the kidneys of anaesthetized freshwater lampreys. [51Cr]EDTA was found to be totally unsuitable for the measurement of GFR in this species.

Nephron filtration rate in conscious rats recovering from anesthesia

1977 ◽  
Vol 232 (4) ◽  
pp. F329-F334
Author(s):  
J. P. Bonvalet ◽  
M. Champion ◽  
F. Wanstok ◽  
G. Berjal
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Experimental Conditions ◽  
Nephron Filtration Rate ◽  
Conscious Rats ◽  
Anesthetized Rats ◽  
Saline Loading ◽  
Single Nephron ◽  
Infusion Technique

Single-nephron glomerular filtration rate (SNGFR) of superficial (S) and juxtamedullary (JM) nephrons was measured in conscious rats with a [14C]ferrocyanide infusion technique. Experiments were carried out in nondiuretic (ND), salt-loaded (SL), and hemorrhagic hypotensive (HH) rats. Mean SNGFR values of S and JM nephrons were 48.7 +/- 4.5 SE and 61.7 +/- 4.2 in ND, 73.6 +/- 8.7 and 87.5 +/- 10.8 in SL, and 29.9 +/- 5.9 and 36.4 +/- 7.1 in HH rats. These values are higher than the values reported in anesthetized rats. The S-to-JM SNGFR ratio was not significantly different in the three experimental conditions (ND, 0.788 +/- 0.032; SL, 0.843 +/- 0.018; and HH, 0.824 +/- 0.030), and did not differ from the values reported in anesthetized rats in similar experimental conditions. It is concluded that anesthesia exerts a depressive effect on GFR, but does not modify intrarenal SNGFR distribution. Neither saline loading nor hemorrhagic hypotension induces SNGFR intrarenal redistribution in conscious rats.

Measurement of nephron filtration in the dog: role of proximal intratubular pressure

1981 ◽  
Vol 241 (3) ◽  
pp. F238-F243
Author(s):  
D. A. Hartupee ◽  
A. H. Gillies ◽  
F. G. Knox
Keyword(s):  
Proximal Tubule ◽  
Filtration Rate ◽  
Free Flow ◽  
Nephron Filtration Rate ◽  
Intratubular Pressure ◽  
Single Nephron Filtration Rate ◽  
Single Nephron ◽  
Proximal Tubular ◽  
Pressure Controlled

Previous studies concerning the measurement of single nephron filtration rate have shown that collections of proximal tubular fluid, in which an oil drop is held in a constant position, do not affect intratubular pressure in the early proximal tubule in the hydropenic rat. Since intratubular pressures are higher in the dog than the rat, we investigated the effect of position-controlled collections on proximal pressure and single nephron filtration rate (SNGFR) in the dog. During position-controlled collections, early proximal pressure fell 5.8 +/- 0.9 mmHg and SNGFR was 76.3 +/- 5.3 nl/min. During proximal re-collections, in which proximal pressure was maintained near the free-flow value using a long immobile oil block, SNGFR was significantly less, 44.4 +/- 5.5 nl/min. For each micropunctured kidney, SNGFR was also estimated by dividing GFR by the number of glomeruli (mean, 5.4 +/- 0.5 X 10(5)). Estimated SNGFR (50.9 +/- 6.3 nl/min) was not significantly different from pressure-controlled SNGFR but was significantly less than position-controlled SNGFR. Accordingly, in the dog, early proximal pressure decreases during position-controlled collection of proximal tubular fluid, resulting in an overestimation of SNGFR. This artifact can be avoided by controlling the intratubular pressure during collection of tubular fluid.

scholarly journals Autoregulation of Single Nephron Filtration Rate in the Presence and the Absence of Flow to the Macula Densa

1974 ◽  
Vol 34 (6) ◽  
pp. 836-840 ◽  
Author(s):  
FRANKLYN G. KNOX ◽  
COBERN OTT ◽  
JEAN-LOUIS CUCHE ◽  
JOSIANNE GASSER ◽  
JOHN HAAS
Keyword(s):  
Filtration Rate ◽  
Macula Densa ◽  
Nephron Filtration Rate ◽  
Single Nephron Filtration Rate ◽  
Single Nephron

Single-nephron filtration rate in the dog

1972 ◽  
Vol 222 (3) ◽  
pp. 667-673 ◽  
Author(s):  
EG Schneider ◽  
RE Lynch ◽  
LR Willis ◽  
FG Knox
Keyword(s):  
Filtration Rate ◽  
Nephron Filtration Rate ◽  
Single Nephron Filtration Rate ◽  
Single Nephron

Effect of parathyroid hormone on the determinants of glomerular filtration in dogs

1985 ◽  
Vol 248 (4) ◽  
pp. F482-F486 ◽  
Author(s):  
G. R. Marchand
Keyword(s):  
Glomerular Filtration Rate ◽  
Parathyroid Hormone ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Apparent Discrepancy ◽  
Oncotic Pressure ◽  
Concomitant Increase ◽  
Filtration Pressure ◽  
Effective Filtration Pressure ◽  
Single Nephron

Elevated levels of parathyroid hormone (PTH) often are associated with reduced glomerular filtration rate (GFR) in humans. Although PTH has been reported to reduce the ultrafiltration coefficient (Kf) in rats, GFR declined only if they were plasma expanded. In contrast, PTH does not reduce GFR in dogs, despite filtration pressure disequilibrium. To evaluate this apparent discrepancy, the determinants of GFR were measured in acutely thyroparathyroidectomized dogs. In the absence (n = 8) and presence (n = 10) of synthetic bovine PTH, GFR was 29 +/- 3 and 26 +/- 2 ml/min; Single nephron glomerular filtration rate was 58 +/- 4 and 51 +/- 3 nl/min; glomerular plasma flow was 248 +/- 22 and 250 +/- 24 nl/min; glomerular capillary pressure was 58 +/- 2 and 61 +/- 3 mmHg; Bowman's space pressure was 19 +/- 2 and 19 +/- 1 mmHg; and systemic oncotic pressure was 19 +/- 0.8 and 18 +/- 0.5 mmHg. Average effective filtration pressure (EFP) was significantly greater in the presence (18.6 +/- 1.3 mmHg) than in the absence (14.6 +/- 0.9 mmHg) of PTH. Therefore, Kf per glomerulus calculated from these data was significantly (P less than 0.01) less in the presence than in the absence of PTH (2.91 +/- 0.29 and 3.98 +/- 0.16 nl X min-1 X mmHg-1, respectively). It is concluded that PTH reduced Kf. Whereas this effect predicts reduced GFR in dogs, given filtration pressure disequilibrium, a concomitant increase in EFP maintained GFR in the present study.

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