Parabiotic Intoxication in F 1 Hybrid Mice After Immunological Depression of the Parent Strain. ∗

Abstract

Summary

(1) Four out of 10 isologous parabiotic pairs showed AP at 5 days but this was no longer present 12 days after union. (2) Neonatal thymectomy of the parental strain partner put in parabiosis with the corresponding F₁ hybrid did not significantly alter the course of parabiotic intoxication in the latter. (3) Lethal X-irradiation of the parental strain partner had no effect upon AP at 5 days, but AP was eliminated by the 12th day after union. In this instance clinical wasting was not present and survival of the pairs was considerably prolonged. (4) It is concluded that parabiotic intoxication observed in parent F₁ hybrid combinations proceeds in two phases: an early phase in which the anemia-polycythemia picture depends upon a vascular pressure gradient established from the F₁ hybrid to the parent, and a later phase in which the pressure gradient is sustained by an immunological reaction elicited by the parent strain partner against the hybrid.