Effect of LSD-25 on Body Temperature of Pigeons

¹ From the Physiology Division, Directorate of Medical Research, U. S. Army Chemical Warfare Laboratories, Army Chemical Center, Maryland

The body temperature of pigeons decreases following the subcutaneous administration of LSD-25. This temperature decrease at 1 hour postinjection shows a straight line relationship to the log of the dose between 1 and 250 µg/kg. Maximal response occurs at 1–2 hours and is followed by a rapid but incomplete recovery toward normal by 4–6 hours. Successive daily injections for 2 days show that no refractoriness develops to this compound within this time period. Simultaneously with the temperature response, the oxygen consumption and heart rate decrease while the breathing rate increases greatly. The temperature decrease is due, therefore, to both reduced heat production and increased heat loss.