Arterial blood epinephrine levels during hemorrhagic hypotension in dogs.

Eight dogs were hemorrhaged by 5-ml/kg increments at 6–10-minute intervals until the animals died after an average time of 73.5 minutes. Arterial blood epinephrine levels were quantitatively estimated using a rat uterus as a test object driven by an automatic stimulating device. Significant quantities of epinephrine were found in the blood after a hemorrhage of 15 ml/kg and reached a maximum of 37.2 ug/l., as the bitartrate, after a total hemorrhage of 40 ml/kg. The maximum eplnephrine levels observed during hemorrhagic hypotension were in the range of those found 2 minutes after the intravenous injection of 0.05–0.10 ml/kg epinephrine and could be expected to produce marked physiological effects.