TY - JOUR T1 - THE EFFECTS OF GENERAL ANESTHESIA ON THE MUSCULAR ACTIVITY OF THE GASTROINTESTINAL TRACT A STUDY OF ETHER, CHLOROFORM, ETHYLENE AND NITROUS-OXIDE JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 41 LP - 59 VL - 27 IS - 1 AU - G. H. MILLER Y1 - 1926/02/01 UR - http://jpet.aspetjournals.org/content/27/1/41.abstract N2 - During the surgical stage of anesthesia with ether or chloroform, there is marked loss of tonus and almost complete inhibition of both rhythmic and peristaltic contractions in stomach, small intestine and colon. During the recovery period, the stomach recovers slowly and continues to show some degree of depression for one hour or longer. The small intestine and colon recover very rapidly after stopping the anesthetic and show increased activity. The small intestine develops exaggerated peristalsis, while the colon shows a marked increase in tonicity. The relatively light, surgical anesthesia, usually maintained with ethylene, causes no marked change in the activity of the gastro-intestinal tract. A slight increase in tonicity and amplitude of contractions has sometimes been observed. During the post-anesthetic period, also, there is no marked change in muscular activity. A slight decrease in activity is often observed about an hour after the anesthesia. Nitrous-oxide anesthesia produces a marked increase in the size of contractions of stomach, ileum and colon. This is probably due to anoxemia. On discontinuing the nitrous-oxide, there occurs promptly a very marked inhibition of activity in these three portions of the gastro-intestinal tract. Tone is lowered, peristalsis ceases, and segmental contractions are much diminished. This depression will usually last one hour or longer. The effects of general anesthesia on a denervated loop of ileum do not differ essentially from those observed on a loop with intact nerve supply. This indicates that the effects, produced in the gastro-intestinal tract during anesthesia, are due chiefly to an action on intrinsic structures. ER -