This study was undertaken in an attempt to define the mechanism whereby intravenous glucagon enhanced bile duct and gallbladder opacification at the time of infusion cholangiography. Seven post-operative gallstone patients with indwelling t-tubes were given a 1 h infusion of intravenous iotroxamide at a rate of 4.1 mg/kg body weight/min. Bile samples were collected by gravity drainage and assayed for iotroxamide and hence biliary iodine concentration. At the end of the 1 h infusion the mean biliary excretion rate (+/- s.e.m.) of iotroxamide was 26.1 +/- 3.4 mg/min and the iodine concentration in bile 9.7 +/- 1.2 mg/ml. 1 mg of intravenous glucagon given over 30 s at the end of the iotroxamide infusion produced a significant increase in bile flow (P less than 0.01). The excretion rate of iotroxamide rose rapidly following glucagon to reach a peak value of 43.8 +/- 8.1 mg/min 5 min after the glucagon (P less than 0.05). The enhanced biliary excretion of iotroxamide resulting from the glucagon injection was significant (P less than 0.05) 1, 3 and 5 but not 10 min after the hormone. The intravenous glucagon also caused a small but significant (P less than 0.05) elevation of the biliary iodine concentration to 10.9 +/- 1.2 mg/ml, 3 min after its injection, but by 5 min post-glucagon the iodine concentration in bile had reversed to pre-injection levels. The possible clinical implications of these results are discussed.
Adult Aged