[ECG changes associated with PGF2 alpha injection into the basal cistern of rabbits]

In the previous studies by the authors, it was shown that various types of changes in electrocardiograph were produced by injection of a small dose of PGF2 alpha into the basal cistern of rabbits which were studied to examine the mechanisms of those in humans with subarachnoid bleeding. In this study with reference to elucidating nerve pathways of PGF2 alpha produced stimulation, changes in electrocardiograph were examined in three groups of the animals which underwent dissection of the spinal cord either at C2-3, or at Th7-8, or bindings of bilateral suprarenal artery and vein, prior to the administration of PGF2 alpha into the basal cistern. The administration of PGF2 alpha decreased more significantly appearance rate of electrocardiographic alterations in the animals following spinal cord dissection at C2-3, and bindings of the suprarenal vessels than the animals with spinal cord dissection at Th7-8. It was concluded that the development of these electrocardiographic abnormalities was caused by direct autonomic discharges to the heart as well as by increased circulating catecholamines.