SODIUM CHLORIDE INTAKE OF ADRENALECTOMIZED RATS WITH LATERAL HYPOTHALAMIC LESIONS

Rats which had recovered from a temporary adipsia and aphagia following lateral hypothalamic lesions were adrenalectomized and given access to a saline solution to determine whether they would respond to the heightened need for sodium by increased voluntary saline ingestion. In the first experiment the rats were given milk as the sole source of food so that intake of additional fluid would not be necessary to maintain water balance. An isotonic saline solution was also available ad lib. Unlesioned rats began to ingest the saline after adrenalectomy. Lesioned rats did not ingest the saline after adrenalectomy and developed symptoms of sodium deficiency. In the second experiment the rats were fed dry Purina chow and given a choice between isotonic saline and water to drink. The lesioned rats manifested some increase in saline intake after adrenalectomy but did not accurately regulate saline and water intake when the concentration of saline was altered.