Effects of histamine receptor stimulation on diseased gallbladder and cystic duct.

The effects of histamine receptor stimulation on the motility of diseased human gallbladder and cystic duct were studied on tissue strips in vitro. Histamine produced concentration-dependent contractions in normal tissues and in tissues from each disease group, but the sensitivity of the strips to histamine as measured by the median effective dose was dependent upon the grade of disease: normal, 90.0 microM; mild chronic cholecystitis, 32.4 microM; advanced chronic cholecystitis, 12.5 microM; and acute cholecystitis, 3.0 microM. There were no differences in histamine sensitivity among different regions (body, neck, and cystic duct) of the biliary system. Studies with receptor-selective agonists and antagonists indicated that the contractile effects were mediated via histamine H1 receptors. Histamine H2 receptor agonists caused only small relaxant responses in about 30% of strips from gallbladder body, but were without effect in gallbladder neck and cystic duct. We conclude that the effects of histamine on the motility of diseased human gallbladder may depend upon the severity of the cholecystitis.