MORPHOLOGICAL AND HAEMATOLOGICAL STUDIES OF THE IN VIVO EFFECT OF PHYTOHAEMAGGLUTININ, POKEWEED MITOGEN, AND BACILLUS CALMETTE‐GUÉRIN ON DBA/2 MICE

Abstract

Intraperitoneal injection of either PHA, PWM, or BCG in DBA/2 mice had no effect on the haemoglobin concentration and leucocyte count. A transformation of the lymphocytes of the peripheral blood to large blast‐like DNA‐synthesizing cells—as seen in vitro—did not occur. Repeated injections of BCG produced a displacement of the blood differential count towards a higher percentage of granulocytes. Both PHA and PWM produced a significant increase in the spleen weight, corresponding to a significant enlargement of the germinal centres and an increased cellularity of the red pulp with large pyroninophilic blast‐like cells. The lymph nodes were characterized by partial disorganization of the follicular structure followed by enlarged germinal centres and increased cellularity, partly consisting of blast‐like cells. A single injection of BCG did not prodvice any significant changes in the spleen and lymph nodes. In contrast to this, administration of BCG twice at an interval of two weeks caused a significant increase in the spleen weight, accompanied by morphological alterations in the spleen and lymph nodes, essentially similar to those brought about by PHA and PWM. The bone marrow and thymus remained unaffected by PHA, PWM, and BCG.