[Effect of hydrocortisone on the sodium and potassium content and distribution in rat hippocampus sections]

Slices of the rat hyppocampus (CA2 region) were incubated in blood plasma, and the content of Na and K in them, and also distribution of these elements in the extra- and intracellular space (by the inulin method) after hydrocortisone (HC) administration was investigated. Special morphological studies had shown that the first slices embraced the dense neuron cell bodies layer; the next slices (deeper ones) had much less neurons. A single dose of HC given 3 hours before the experiment in doses of 1 and 5 mg per 100 g of body weight caused a decrease of intracellular Na concentration and an increase of intracellular K in the first slices; the transmembrane distribution coefficient was elevated for both ions. After 7-day HC administrattion the changes described practically disappeared. The second slices (having only a few neuron cell bodies) showed no significant changes in the electorlyte composition in all the experiments conducted.