Abstract
Transport systems for organic compounds are immature in the kidney of most newborn animals. Measured in vitro, uptake of p-aminohippuric acid (PAH) into renal cortical slices is low in tissue from 2-week-old rabbits, peaks at 4 weeks and declines to adult levels. To minimize limitations encountered with the slice technique, a separated tubule preparation was employed to estimate transport. Segments of proximal tubules were prepared by incubating renal cortex in 0.375% collagenase-Ringer solution. The tubules were washed, filtered, suspended in a Ringer-acetate solution containing dilute PAH, oxygenated and incubated at 25°C. The tubules from young animals consumed oxygen to the same extent as those from adult. Intracellular concentrations of sodium and potassium were similar at each age tested. Maximal PAH uptake (T/M ratio) was Obtained after approximately 30 minutes of incubation in tissue from animals of all ages. Adult T/M ratios were significantly higher in the presence of acetate. The maximal PAH T/M ratio was less at 2 weeks than at 4 weeks which was less than adult. pretreatment with penicillin significantly enhanced T/M ratios at 2 weeks. This technique may serve as a superior method of studying the normal development of organic anion transport and factors influencing this developmental process.
Footnotes
- Received January 15, 1974.
- Accepted April 22, 1974.
- © 1974 by The Williams & Wilkins Co.
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