The steep dose-response curves of anesthesia.

To the Editor:—The critique by Eger et al. on the article by Eckenhoff and Johansson concerns combining the dose–response curves of several ion channels to make them steeper. The slopes of the in vivo studies are steep, whereas those of the in vitro studies are gradual. Both groups anticipate that when several binding sites among ion channels are combined, the dose–response curves may become steeper. The computation procedures were different. However, all dose–response curves become steep when plotted as quantal responses (hit or no-hit). In anesthesia, the animal responses are typically plotted as anesthetized or nonanesthetized (quantal response). The Hill equation starts with the following form, where n molecules of an anesthetic A bind to the receptor R: