Abstract
The solution of the question of the liberation of epinephrin into the adrenal veins and the estimation of the amount so liberated in the absence of artificial stimulation of the splanchnics are complicated by the fact that after withdrawal of blood pressor substances are quickly developed in it, which give the same effect as epinephrin on such objects as the vessels of a frog's legs. 2 It is therefore desirable to demonstrate the fact of its liberation and to assay its amount without the necessity of withdrawing blood. We have done this (in the cat) by means of the denervated eye reactions (of Meltzer), 3 and by the effect on the blood pressure curve.
1. For the eye reactions all that is necessary is to clamp off temporarily a pocket of the inferior vena cava so that only adrenal vein blood enters it. A clamp is applied just above the iliac veins. The renal veins are then clamped and the segment of cava emptied of blood by gently stripping it upwards. Finally a clamp is put on the cava above the adrenal veins. Only a few seconds are occupied in the adjustment of these clamps. Small branches of the segment of cava have been previously tied. The pocket is allowed to fill with blood from the adrenals. When the clamps are removed, the eye reactions are elicited at practically the same time interval as when the splanchnics are stimulated with the vessels free.
2. After section of both splanchnics (above the diaphragm) the reactions can no longer be obtained. Section of the splanchnics has therefore greatly diminished, if not abolished, the liberation of epinephrin. This is not due to the low blood pressure caused by division of the nerves.
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