THE EFFECT OF CERTAIN ANALGESIC DRUGS AND ADRENAL CORTICAL HORMONES ON THE BRAIN OF NORMAL AND HYPOPHYSECTOMIZED RATS AS MEASURED BY THE THIOBARBITURIC ACID REAGENT

¹ Department of Physiology and Pharmacology, Duke University School of Medicine, Durham, North Carolina

1. Morphine, meperidine, and methadone as well as epinephrine when injected into animals for a period of time increased the ascorbic acid catalyzed oxidation of linolenic acid in the brain as measured by the TBA test. Codeine, dionin, and apomorphine produced a lesser increase. Cocaine, salicylate, and sodium pentobarbital had no effect.

2. In the hypophysectomized animal the first four drugs produced no change in brain TBA values although they still produced analgesia.

3. Injection of adrenal cortical hormones increased the brain TBA values in normal and hypophysectomized animals.

4. Morphine, meperidine and methadone thus apparently cause a release of ACTH from the hypophysis.

5. It is suggested that there may be some parallelism between certain central effects produced by the adrenal cortical hormones, and the drugs which cause their release, and the reaction measured by the TBA test.