Abstract
The effect of rapid extracellular fluid expansion with saline was studied in 9 fetal lambs with intact umbilical circulation between 100-120 days gestation. After control measurements of UV, UNaV, GFR, % TNa, CH2O, serum total protein (T.P.), Hct and [Na+], 0.45 N NaCl was infused rapidly into the fetus until the increase in UV was stable. After expansion, serum [Na+] did not change but the T.P. and Hct fell significantly. There was a 13 fold increase in UV from 0.24 ml/min to 3-31 ml/min. The control GFR increased from a mean of 3.21 ml/min to 7.42 ml/min. The initial % TNa decreased from 97.2 to 85.9 and UNaV increased from 13.6 mnoles/min to 368.2 mmoles/min. CH2O increased from 5.1 to 15.4 ml/min. These data indicate that the control % TNa in the fetal lamb is relatively low and might reflect the larger basal ECF volume during this period. This low % TNa produces an increase in distal delivery of filtrate and a relatively high control CH2O and dilute urine. Rapid hypotonic ECF expansion results in a significant decrease in % TNa and a significant increase in GFR, UV, CH2O, and UNaV. These data show that the fetal proximal renal tubule is sensitive to ECF expansion and that distal TNa is efficient as CH2O significantly increased as UV and UNaV increased.
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Moore, E., Galvez, M., Paton, J. et al. RENAL RESPONSE TO HYPOTONIC VOLUME EXPANSION IN THE FETAL LAMB. Pediatr Res 8, 458 (1974). https://doi.org/10.1203/00006450-197404000-00710
Issue Date:
DOI: https://doi.org/10.1203/00006450-197404000-00710