Effect of a cholecystokinin receptor antagonist (loxiglumide) on gallbladder contractile function in guinea pigs.

We evaluated the effect of the specific cholecystokinin (CCK) receptor antagonist, loxiglumide, on gallbladder contractile function in guinea pigs. Five mg/kg body weight (BW) of loxiglumide was administered orally to guinea pigs once a day for 3 days. We then investigated gallbladder contractile function and plasma CCK concentrations in the guinea pigs. Maximal gallbladder pressure induced by cerulein was significantly depressed on the 1st and 3rd days following loxiglumide administration. On the 1st day, the plasma CCK concentration was significantly increased compared with that of the control group during fasting and 15 min after the administration of an intraduodenal test meal. These results suggest that the disturbed gallbladder contraction is due to the competitive inhibition of CCK by loxiglumide. Gallbladder contractile function in guinea pigs is depressed by loxiglumide; however, this effect is reversible after short-term loxiglumide administration.