The Effect of Saline Infusion on Sodium Reabsorption by the Proximal Tubule of the Dog*

Dirks, John H.; Cirksena, William J.; Berliner, Robert W.

doi:10.1172/jci105223

Cited by 322 publications

(171 citation statements)

References 17 publications

Supporting

Mentioning

143

Contrasting

Unclassified

Order By: Relevance

“…During hypotonic saline loading, expansion of extracellular fluid resulted in a progressive inhibition of sodium reabsorption at the proximal tubule, thereby increasing delivery of filtrate to the distal nephron [7,9,14]. At peak free water diuresis, when antidiuretic hormone activity is minimal or absent, (C H20 + C Na ) [18,19] provides an indirect index of distal sodium supply and the urinary flow represents the volume of filtrate reaching the ascending limb [16].…”

Section: Discussionmentioning

confidence: 99%

Studies on the Site of Renal Salt Loss in a Patient with Bartter's Syndrome

et al. 1973

View full text Add to dashboard Cite

A child with growth retardation, hypokalemic alkalosis, and urinary salt losing is described. Pressor response to angiotensin II was reduced and renal biopsy showed striking hyperplasia of the juxtaglomerular apparatus.Renal tubular function was studied in the patient and in healthy control subjects during hypotonic saline diuresis. Glomerular filtration rate (GFR) was 128 ml/min/ 1.73 m 2 in the patient and 129 ±30 ml/min/1.73 m 2 in the control subjects. Fractional sodium delivery to the distal nephron, as estimated by (C H2 o + C Na )/100 ml GFR, was 13.3 ml and 11.1 ± 3.5 ml in the patient and normal subjects, respectively. Sodium transport at the diluting segment [(CH 2 O/CH 2 O + C Na ) X100] was markedly impaired in the patient, 32% versus 80% ± 9.2% in the control subjects. The natriuretic effect of chlorothiazide was normal in the patient, which suggests that the reabsorptive capacity of the thiazide-sensitive segment of the distal nephron is preserved. The evidence presented suggests that the defective reabsorption of sodium in the patient is due to an impaired sodium transport in the ascending limb of Henle's loop. The present study raises the possibility that a similar tubular defect may be responsible for the impaired renal handling of sodium that is often observed in patients with Bartter's syndrome. Speculation

show abstract

Section: Discussionmentioning

confidence: 99%

Studies on the Site of Renal Salt Loss in a Patient with Bartter's Syndrome

et al. 1973

View full text Add to dashboard Cite

show abstract

“…The natriuresis of saline loading is chiefly a result of increased tubular rejection of sodium because the net tubular reabsorption of sodium follows in parallel with the filtered load (Stein, Bercovitch & Levitt, 1964). Dirks, Cirksena & Berliner (1965) and Watson (1966) have further shown that this natriuresis of saline loading in the dog is accompanied by an increased tubular rejection fraction of sodium in the proximal tubule during micropuncture studies. Watson (1966) concluded that all the increased sodium excreted could be accounted for by the decreased fractional reabsorption of sodium in the proximal tubule.…”

Section: Relative Importance Of Tubular Rejection and Filtered Loadsmentioning

confidence: 91%

Analysis of Direct Renal Actions of Alpha and Beta Adrenergic Stimulation Upon Sodium Excretion Compared to Acetylcholine

Pearson

Williams

1968

British Journal of Pharmacology and Chemotherapy

View full text Add to dashboard Cite

“…In the doses used in this study and in the absence of secondary contraction of extracellular volume, this is likely the case (16)(17)(18)(19)(20). The high concentration of amiloride required to block Na+-H' exchange in the proximal tubule makes it unlikely that this action is physiologically relevant (2 1).…”

Section: Discussionmentioning

confidence: 99%

Effects of Euvolemic and Hypervolemic Hyperbicarbonemia on Segmental Nephron HCO3 Reabsorption in the Newborn Dog1

Lorenz

1990

Pediatr Res

View full text Add to dashboard Cite

ABSTRACT. Studies were undertaken to determine the effect of elevated plasma bicarbonate concentration (PHC03) with and without volume expansion on segmental nephron H C 0 3 reabsorption in newborn and adult dogs using the technique of distal blockade. Reabsorption of bicarbonate per mL glomerular filtrate (RHC03lGFR) in the proximal nephron was more suppressed in euvolemic newborns than euvolemic adults as PHC03 was increased from baseline to 50-70 mM. Inasmuch as total nephron reabsorption has been shown to be essentially complete under these conditions in both newborns and adults, distal nephron H C 0 3 delivery and the fraction of the distal H C 0 3 load reabsorbed must have been greater in euvolemic newborns than adults when P H C 0 3 was elevated. Total nephron RHC03/GFR was less suppressed by NaHC03 volume expansion in the newborn than it was in the adult. However, proximal nephron RHC03/GFR was similarly suppressed by NaHC03 volume expansion in newborns and adults. Thus, the NaHC03-expanded newborn must have reabsorbed a greater proportion of the increased distal HC03 load than did the NaHC03-expanded adult. Proximal nephron H C 0 3 reabsorption is a balance between reabsorption effected by active proton secretion and passive H C 0 3 back leak. Euvolemic increase in peritubular HCO3 concentration has been shown to suppress proximal tubular proton secretion; volume expansion increases proximal tubule H C 0 3 permeability and back leak. Thus, we interpret these results to indicate that: 1 ) the limited capacity of the immature proximal tubule for proton secretion is most likely responsible for the greater suppression of proximal RHC03/GFR by increased PHC03 in euvolemic newborn dogs compared with adults; 2) the increase in H C 0 3 permeability of the immature proximal nephron with volume expansion is no greater than that which occurs in the mature proximal nephron with volume expansion; and 3) the immature distal nephron displays a greater propensity for HCO3 reabsorption as PHC03 is increased than does the mature distal nephron, with or without volume expansion. (Pediatv Res 27: 604-611, 1990) Abbreviations FRHC03, fractional reabsorption of the filtered bicarbonate load GFR, glomerular filtration rate PHC03, plasma bicarbonate concentration

show abstract

The Effect of Saline Infusion on Sodium Reabsorption by the Proximal Tubule of the Dog*

Cited by 322 publications

References 17 publications

Studies on the Site of Renal Salt Loss in a Patient with Bartter's Syndrome

Studies on the Site of Renal Salt Loss in a Patient with Bartter's Syndrome

Analysis of Direct Renal Actions of Alpha and Beta Adrenergic Stimulation Upon Sodium Excretion Compared to Acetylcholine

Effects of Euvolemic and Hypervolemic Hyperbicarbonemia on Segmental Nephron HCO3 Reabsorption in the Newborn Dog1

Contact Info

Product

Resources

About