-AMINO ACIDS AND VARIOUS BIOGENIC AMINES AS ANTAGONISTS TO PENTYLENETETRAZOL

¹ New York Medical College, Flower and Fifth Avenue Hospitals, New York, New York

Some catecholamines, primary indole ethylamines including serotonin, histamine and -aminobutyric acid (GABA), when administered intravenously, produced sleep in chicks at an age when the blood-brain barrier was incompletely formed, but not in older chickens with a completely mature blood-brain barrier. This response in the chick was characterized by roosting posture, closed eyes and head resting on breast. These compounds effectively prevented pentylenetetrazol (PETZ) convulsions in 1-day-old chicks. Of seven -amino acids studied, GABA was the most effective anticonvulsant against CD90 PETZ. Anticonvulsant activity was not dependent on depressant action, since bufotenine and two analogs which produced gross behavioral excitement also protected against PETZ convulsions. This investigation illustrated the usefulness of the chick for studying the actions of drugs in nonpathologic absence of the blood-brain barrier.