Abstract
Anisotropine methylbromide (A.M.; Valpin®) is a tropine ester related structurally to atropine and homatropine methylbromide, and has been synthesized by Gordon and Weiner (1). The chemical name is 2-propylpentanoyl tropinium methylbromide and structural formula is as shown in Fig. 1.
In previous experiments, Taira et al. (2) found that the vocalization response of dogs to acetylcholine (Ach) administered into a branch of the mesenteric artery was selectively abolished by atropine. On the other hand, sodium salicylate was also found to be effective for prevention of the vocalization response to Ach, although a larger dose was needed in the mesenteric artery than in the femoral. They concluded that the vigorous contraction of the intestine through a muscarinic mechanism probably plays an important role in the induction of the nociceptive response, although possible involvement of other mechanisms cannot be ruled out. In the present experiments the analgetic effect of A.M. and of its mixture with sulpyrine was assessed, the procedure being essentially the same as described by Taira et al. (2) and Nakayama et al. (3).
