Studies on the Development of Inflammatory Lesions : II. Influence of Cortisone and Methylandrostendiol on the Tissue Reactions Caused by Dead Tubercle Bacilli

Abstract

Tubercle bacilli of the human type (H37Rv) killed by heating and drying were inserted into the subcutis of albino rats and the tissue reactions were examined. These were compared with tissue reactions of rats receiving cortisone or MAD (Methylandrostendiol). The lesions which developed around the bacilli were examined histologically 3 days, 1 week, and 3 weeks after the insertion. The findings can be summarized as follws. 1. An enormous migration of polymorphonuclear leucocytes and their rapid degeneration and destruction were observed in the early stage, and then this migration decreased. 2. In the next stage, mononuclear cells such as monocytes appeared as leucocytes disappeared, and the masses of dead bacilli were phagocytized and destroyed cellular fragments appeared. Some of these cells changed their shape to look like epithelioid cells. Langhans type of giant cells also appeered. Thus, tuberculosis like lesions developed but no caseation was found. 3. The production of fibroblasts and collagenous fibers and the formation of blood capillaris could be seen in the outer zones of lesions. A tendency towards encapsulation followed. 4. Cortisone caused a characteristic inhibition of fibroblasric response and the general cellular reaction was decreased. In spite of these alterations, the lesion does not spread in contrast to that caused by living bacilli. 5. In the case of MAD administration, there were a characteristic fibroblastic rerponse and tendency towards capsule-formation.