An experimental obliterating thromboangiitis limited to the posterior part of the body.

After a brief outline of the principles involved in the production of thrombohemorrhagic phenomena (THP) with special organotropic localizations, an experimental technique is described which permits the production of acrocyanosis and thrombohemorrhagic lesions largely limited to the posterior part of the body. This phenomenon can be consistently produced by certain combinations of THP elicitors, anaphylactoid agents and noradrenaline (NA). The most effective combination among those tested is thorium dextrin (Th-Din) plus tannic acid plus NA. Several drugs can decisively influence the course of this reaction. Most otable among these are Neo-Antergan (an antihistaminic) which sensitizes for the production of the aboral THP, while heparin (presumably through its anticoagulant effect) and Dibenamine (presumably through its antiadrenergic action) offer virtually complete protection. When only Th-Din plus tannic acid is given, there develops an intense but reversible cyanosis in the hind paws and tail; additional treatment with NA induces obliterating thromboangiitis with hemorrhages and gangrene. None of hese changes are produced by Th-Din, tannic acid or NA alone. Evidently, here, e are dealing with pluricausal experimental diseases whose possible relationship to Raynaud's disease, thromboangiitis obliterans and anaphylactoid purpura is briefly discussed.