Development of the 'lipoid theory of narcosis' inGerman-speaking countries in the 19th century:from Bibra/Harless to Meyer/Overton

摘要

There are some important steps in the development of the so-called lipoid theory of narcosis in German-speaking countries: Bibra and Harless: Ernst von Bibra and Emil Harless found that anesthetics dissolve ordinary fat. Through quantitative estimation of fat contents in the brain of normal and narcotized animals, they concluded that anesthetics directly remove fat-like substance from the brain. Hermann: Ludimar Hermann discovered lecithin in red blood celis. As anesthetics, such as ether and chloroform, are capable of dissolving red blood cells, he conjectured that they would dissolve lecithin as well. Hermann assumed that the parallel functions of anesthetics on lecithin and on the red blood cells are the basis for narcotism of the central nervous system. Pohl: Julius Pohl investigated the storage of chloroform in red blood cells and in the brain. He assumed that it is found on the content of lipoid substances. He pointed out that the solubility of chloroform in fatty substances could be the reason for its narcotic properties. Meyer and Overton: Hans Meyer and Ernst Overton developed the correlation of anesthetic potency with solubility in olive oil. They proposed that anesthetics somehow must have worked at the lipid, lipophilic and/or hydrophilic sites ("lipoid theory of narcosis"), exhibiting similar functions they display in olive oil.