The effects of whole bile and bile salts on the innervated and the denervated heart

Abstract

The effects of the intravenous administration of whole bile and bile salts on the blood pressure and the electrocardiogram were studied in a series of acute experiments, under pentobarbital sodium (nembutal) anesthesia, on normal dogs and on dogs with denervated hearts; the same methods and technical procedures were employed in both cases. Similar observations were made over a period of several weeks on normal, trained dogs, and on one trained dog with a denervated heart; this permitted us to make repeated observations which could not have been influenced by anesthesia, operative trauma, or an accumulative effect of successive injections of bile. There were no detectable electrocardiographic differences between the effects of whole bile and bile salts on the innervated and the denervated heart; the irregularities and slowing of the rate of the heart were similar. During the period of gradual recovery from the hypotensive effect brought about by the first injections of bile constituents, the blood pressure of the dogs with denervated hearts usually did not return to its previous level, but the blood pressure of the dogs with innervated hearts, usually tended to do so. In both the normal animals and those with denervated hearts, approximately the same, gradual, hypotensive effect was produced by the intravenous administration of repeated doses of whole bile or bile salts. The injections finally led to failure of the heart, fall of blood pressure, and death of the animal. Our observations on the innervated heart differed so slightly from those on the denervated hearts of otherwise intact dogs to which whole bile or bile salts were administered intravenously, that it appears justifiable to conclude that whole bile and bile salts can produce practically the same hypotensive effect and cardiac changes, such as bradycardia and disturbances in rhythm, in the absence, as well as in the presence, of the cardiac autonomic nerves.