Epinephrine-induced hemoconcentration in the domestic hen

The effect of 150 µg/kg epinephrine intravenously on the packed cell volume (PCV) was studied in 24 laying hens. The PCV was observed to rise to a peak between 20 and 30 minutes after injection and to gradually return to the preinjection level after 1–2 hours. T-1824 disappearance curve analysis, repeated plasma volume determinations and direct red cell volume measurements, using Cr51-tagged red cells, substantiate the conclusion that the response is due to loss of fluid from the vascular system with resultant concentration of the erythrocytes already present. The possible relationship of the pressor effect of epinephrine and of the role of the kidney to the response is considered.