The endolymphatic perfusion of lymph nodes with toxic materials.

Individual lymph nodes of sheep were perfused, via a cannula in one of their afferent lymphatics, with a variety of toxic materials. This procedure was designed to ablate the parenchyma of the nodes so that the macrophage-rich afferent lymph would pass unaltered into the efferent duct, which also had been cannulated. Although many materials caused transient inflammation and/or immunoblastic responses, few caused lasting alterations in the cellular composition of the efferent lymph. Only melphalan, an alkylating agent, succeeded in damaging the internal structure of the nodes so that true afferent lymph appeared in the efferent duct and abundant dendritic macrophages could be collected. In the doses necessary to achieve this enough of the melphalan became systematized to produce a transient alopecia.