Attempts to Visualize the Gail-Bladder of the Rabbit with Tetraiodophenolphthalein

Abstract

In previous work 1 we were unsuccessful in attempts to record a gall-bladder contraction in the rabbit on the injection of cholecystokinin. It was reasonable to suppose by analogy from Graham's and Cole's 2 work, that we would be able to study the problem roentgenologically, after the administration of sodium tetraiodophenolphthalein. Graham, Cole and Copher 3 report that they have visualized the gall-bladders of rabbits after the subcutaneous injection of sodium tetrabromphenolphthalein, but add that these shadows were faint and inconsistent.

We hoped to get more consistent results using intravenous injections of tetraiodophenolphthalein. Because of our early failure in 4 rabbits to get shadows with the usual doses of 0.2 gm. per kilo, we increased the amount. Four rabbits were given 0.3 gm. per kilo, one of which showed toxic symptoms. One of 2 rabbits given 0.4 gm. died in 4 hours. Twenty-four rabbits were given the usual dose of 0.2 gm. per kilo, which proved fatal in 2 cases. This is in accord with Whitaker and Milliken, 4 who studied the toxicity of tetraiodophenolphthalein and tetrabromphenolphthalein, finding that 0.24 gm. is the largest single non-toxic dose for rabbits, Because of the possibility of missing the time of maximum concentration, which in dog and man is after 14 hours, the dye was given to fasting animals, and pictures taken every 2 hours until 40 hours after the injections. We were uniformly unable to obtain shadows of the rabbit's gallbladder. As control experiments we injected the same dye, in the same dose (0.2 gm. per kilo) in dogs and sharply defined shadows were obtained.

Because of this lack of concentration of the dye in the rabbit, we took specific gravity determinations. We found the rabbit's gallbladder bile to have a specific gravity of approximately 1.048, which is within the lower range of the specific gravity of gall-bladder bile of man and dog.