Anesthesiology
-
The effects of enflurane anesthesia on adrenal medullary catecholamine secretion and on the pressor effect of splanchnic-nerve stimulation were studied in cats given pentobarbital for basal anesthesia. Inhalation of enflurane, 1.2 and 2.2 per cent, caused dose-related inhibition of both spontaneous catecholamine release and secretion evoked by splanchnic-nerve stimulation. ⋯ These results are similar to those previously obtained with halothane and methoxyflurane. It is concluded that the decrease in catecholamine secretion caused by enflurane is in part due to a direct effect on the chromaffin cell, namely to an inhibition of the secretion-stimulating effect of acetylcholine released from splanchnic nerves.
-
Comparative Study
Mucociliary flow in the trachea during anesthesia with enflurane, ether, nitrous oxide, and morphine.
Tracheal mucociliary flow rates in dogs were measured with a radioactive droplet technique during thiopental anesthesia, and subsequently during enflurane, either, and nitrous oxide-morphine anesthesia on different occasions. Enflurane, at 0.6, 1.2, 1.8 MAC, produced a dose-dependent, reversible depression of mucociliary flow equal to that previously reported for halothane. Nitrous oxide-halothane and nitrous oxide-morphine depressed mucociliary flow to the same extent as halothane at equivalent MAC levels. Ether did not depress mucociliary flow significantly from the thiopental control at any MAC level.
-
Disordering, fluidizing and dilating effects of anesthetics upon cell membranes are well recognized. The fluidization can be precisely measured with phospholipid membranes. When phospholipids are dispersed in water, they form globules of bilayer structure. ⋯ The normalized values of the fluidizing action of these drugs at physiologic conditions correlated well with their nerve-blocking potencies. The present results indicate that the uncharged molecules fluidize the lecithin membrane by unsaturable nonspecific binding. The possible effect of the charged molecules upon the fluidity of natural membranes remains to be established.