An Investigation of Renal Function during Histogenesis in the Late Foetal and Neonatal Rat by means of the Uptake and Autoradiographic Localization of Radioactive Potassium Available to Purchase

A technique has been developed for studying the uptake of K⁴² by the foetal rat kidney.

Using this technique the exchange rate for K⁴² of the foetal and neonatal metanephros relative to the foetal and neonatal liver has been investigated. It was found that the metanephros of the 20- and 21-day foetus shows a rate of exchange which is twice that of the liver, whereas the neonatal metanephros shows a rate of exchange which is less than half that of the liver.

The results of this investigation demonstrate that the ratio of K⁴² uptake by the metanephros of the 20- and 21-day rat foetus, relative to that of the foetal liver, is one-quarter of that reported for the adult rat.

An autoradiographic study of the distribution of K⁴² in the foetal kidney has shown that histological localization of the isotope in the proximal and distal tubules, found in the adult, does not occur.