The Rôle of the Lipoids and Particularly Lecithin in Narcosis

It had been known that narcotics are more soluble in fats and oils than in water. With this in mind, yon Bibra and Hatless, 1 in 1847, carried on a series of experiments on rabbits. Half the animals were anesthetized, and the other half were used as controls. All the animals were killed and the fat content of the brains and livers was determined quantitatively by extraction with alcohol and ether. They found the fat content of the brains of the narcotized animals to be less, and that of their livers greater, than the fat content of these organs in the controls. They, therefore, suggested that narcosis is due to a solution of brain lipoids or fats by the narcotic. Reieher (3), working in Salkowski's laboratory, repeatedly demonstrated a considerable increase in the total quantity of fat in the blood during and after narcosis, especially with ether or chloroform. He determined the fat content of the blood by extraction with alcohol and ether. Pfliiger's school 2 has shown that after digesting the residue obtained by this method with pepsin and again extracting with ether an additional quantity of fat may be obtained. Mansfeld (4) has shown that the total fat obtained from the blood by extracting with ether is only half the actual amount of fat present, and he has further called attention to the fact that the lipemia found in phosphorus poisoning is really due, not to an increase in total blood fat, but to a relative increase in free fat.