FURTHER OBSERVATIONS ON THE ACTION OF "CHOLECYSTOKININ"

Abstract

The gall bladder has been observed to contract under direct vision following the injection of "cholecystokinin." This has no effect on liver volume. If vasodilatin is present in the preparation of "cholecystokinin," the change in intra-gall-bladder pressure lasts much longer than the change in liver volume due to the dilatin. "Cholecystokinin" has no detectable effect on gastric motility. Its effect on intestinal motility is variable. Morphine hypo dermically in some animals causes an exaggerated "tonus rhythm" of the gall bladder, which is not materially affected by atropine. Atropine, however, causes some relaxation of the gall bladder. Bile and bile salts administered intravenously cause a relaxation of the gall bladder in effective doses. Ergotamine tartrate stimulates the gall bladder and has no effect on "cholecystokinin" action. MgSO* in 200 mgm. doses (30 lb. dog) diminishes the "cholecystokinin" action, but does not abolish it. The diaphragm, thoracic and abdominal muscles play no part in the action of "cholecystokinin" on the gall bladder. An occasional spontaneous contraction of the gall bladder occurs in some dogs which cannot be accounted for. Dogs vary in their response to "cholecystokinin," the usual effect lasting 10-60 min. Occasionally the gall bladder will not relax, or return to normal for 2 or 3 hrs. after an injection. The gall bladder of the cat and dog are caused to contract on the intravenous administration of an adequate dose of "cholecystokinin." The authors failed to record a contraction for the gall bladder of the rabbit.