Influence of Nalorphine on the Sphincter of Oddi Studied by Roentgencinematography

Abstract

It has long been known that morphine increases the tone of unstriated intestinal muscle in general and hence that of the sphincter of Oddi as well. Most substances belonging to the morphine group, both natural and synthetic, are considered to exercise a similar influence on unstriated muscle. Nalorphine (N -allylnormorphine) (WINTER et colI. 1954) forms an exception in this respect since it is considered that this substance has an antagonistic effect on the tonic action of morphine (HART and MCCAWLEY 1944).During the last few years we have studied the influence of various drugs upon the sphincter of Oddi by means of a system consisting of an image intensifier and a film camera adapted for roentgencinematography. Nalorphine has also come in for attention in this connection, and as our results diverge in certain respects from the view generally held we considered they were worth placing on record.Our knowledge regarding nalorphine as a morphine antagonist is mainly based on experimental and clinical experience with this substance in morphine