Effects of raised intraluminal pressure on gallbladder function and hepatic bile outflow in the cat.

Gallbladder concentrating function and motility and hepatic bile outflow were studied with a perfusion technique in anesthetized cats. The function of the gallbladder distended by an intraluminal pressure of 50 cm H2) was compared with its function at a pressure within the physiological range. It was found that gallbladder distention reduced the rate of net fluid absorption by 53% compared with controls. This reduction was abolished after intravenous administration of indomethacin, a prostaglandin synthetase inhibitor. At raised intraluminal pressure in the gallbladder a slow, continuous increase in the intraluminal capacity was seen. This rate of volume increase was markedly increased after indomethacin administration. A reduction of the hepatic bile outflow after indomethacin was seen in animals with distended gallbladder but not in controls. A mechanism by which gallbladder distention induces biosynthesis of prostaglandins in the gallbladder wall and thereby influences its function is suggested. The results are discussed in relation to clinical findings in man during acute cholecystitis, a situation in which the intraluminal pressure in the gallbladder usually is markedly elevated.