Comparative response of smooth muscle strips of bladder and bowel to various pharmacological agents

Abstract

AbstractIntestinal segments are commonly incorporated in the urinary system as conduits, reservoirs, and as implants in augmentations of bladders. This practice, initiated in 1888 by Tizzone, only became popular in the 1950s. Although both bladder and intestine are composed primarily of smooth muscle, there are significant morphological and functional differences between these tissues. This present study compares the pharmacological properties of intestinal smooth muscle to those of bladder smooth muscle. Ileum was taken as a representative section from small intestine, sigmoid colon from the large bowel, and the bladder body from the urinary bladder.The results can be summarized as follows: Bethanechol (cholinergic agonist) produced a rapid and sustained increase in tension in the bladder, a marked increase in the amplitude and frequency of phasic contractions in the ileum, and a sustained increase in tension in the sigmoid colon. Methoxamine (α‐adrenergic agonist) and ATP (purinergic agonist) produced an increase in tension in the bladder, and reduced the tension in both ileum and sigmoid. Isoproterenol (β‐adrenergic agonist) produced a relaxation in all three tissues.