Reticuloendothelial response in murine leprosy.

Murine leprosy lesions occur most frequently in reti culoendothelial tissue, and bacilli proliferate electively in r eticuloendothelial cell s. A characteristic feature of both primary and metastati c lesions is that they invade mesodermal tissue and develop primarily around vein s and capillaries. This clear r elation to the small vessels is most r elevant as metastati c lesion s occur in the organ s : in the liver around the cen tral vein s and capillari es ~ around the vessels of suhmucous connective tissue in the tubular organs. The same is valid for le .. ion s in the lymph glands, spleen, bon e marrow, or even in the conn ectivetissue cells arolmd the vessels in the pia mater or around the vessels in the epineurium of the peripheral nerves. The interrelation of murine lepros~' and the reticuloendothelial system as well as c[\,pj]]ari es has been carefully studied by Tanimura and Nishimura (6). The question then arises as to what is the reti culoendothelial and capillary endothelial r esponse to this disease which is so closely r elated to these two types of cells, both r epresenting the first defense barrier against injury. W e have inves ti gaten this probl em, and a summary of our observation s is reported in this paper.