Categories of Parabiotic Intoxication: Further Evidence That the Condition Results From Unequal Cross Transfusion

¹ From the Carter Physiology Laboratory, University of Texas Medical Branch, Galveston, Texas

Hematologic studies of parabiotic rats indicate that in addition to pairs in which one twin exhibits anemia and the partner hyperemia (parabiosis intoxication), there are pairs in which an anemic or a hyperemic rat has a normal co-twin. The hematologic status of parabionts cannot accurately be deduced from their coloration, and hence visual categorization of pairs as normal or ‘intoxicated’ is unreliable. Death of one of the partners always causes a fatal anemia to develop in the previously normal twin in healthy pairs, and usually produces the same condition in the previously erythremic partner in intoxicated pairs. The findings are interpreted to mean that the hematologic inequalities of intoxicated pairs represents the effect of unequal transfusion, with one partner gaining blood at the expense of the other; and are thought to be inconsistent with the contention that the anemia of parabiosis intoxication is hemolytic in nature and the erythremia a sludging of erythrocytes resulting in interference with their negotiation of the capillary anastomosis.