Alteration in Mammalian Nerve Metabolism by Soluble and Gaseous Anesthetics

¹ From the Department of Physiology, Cornell University Medical College, New York City

A variety of anesthetics (chloretone, phenobarbital, cyclopropane, nitrous oxide and xenon) in sufficient quantities will reversibly abolish excitation and conduction in isolated rat sciatic nerve. Under these conditions, in parallel experiments certain aspects of the resting respiration (O₂ consumption) and carbohydrate metabolism (pyruvate utilization) of mammalian nerve have been measured. The rate of O₂ uptake in resting nerve may be significantly diminished by at least four of these agents under conditions which do not alter excitation and conduction. Blockade concentrations or partial pressures were found to inhibit the resting respiration of nerve from 50–85%. Pyruvate utilization by nerve was not always diminished by anesthetics in a manner parallel to the alteration in the resting respiration. An equivalent depression of electrical activity produced in nerve by each substance was by no means accompanied by the same pattern of alteration in nerve metabolism. These results are similar to those of Larrabee and Edwards (1955) obtained with rat autonomic ganglia although quite different anesthetic agents were employed.