EFFECT OF CORTICOSTEROID HORMONES ON INDUCTION AND DEVELOPMENT OF ACUTE MILIARY TUBERCULOSIS IN RABBITS

II. Biochemical and Bacteriological Observations

Abstract

In view of a noticeable increase in the incidence of acute miliary tuberculosis patients in recent years, a roentgenological and histopathological study was made on the effect of corticosteroid hormones (CS) on acute miliary tuberculosis experimentally produced in rabbits, and the result was already reported in the previous paper. The present paper describes the results of further study on the effect of CS on the functions of polymorphonuclear leukocytes (PMN) from blood and peritoneal exudate and macrophages (Mφ) from peritoneal exudate of BCG-sensitized and non-sensitized rabbits, which was made for the purpose of clarifying the mechanism of aggravating effect of CS on experimental miliary tuberculosis. The functions of these cells were assessed by measuring the activities of lysosomal enzymes and bactericidins released from the cells and phagocytic index of the cells as markers. The results obtained are summarized as follows:
1. In both in vivo and in vitro experiments, it was recognized that peritoneal PMN and MO from the CS-treated rabbits showed a decrease in release of lysosomal enzymes (acid phospha tase, β-glucuronidase and lysozyme) and bactericidins from the cells and lowering of phagocytic index of the cells, as compared with the release of enzymes and bactericidins and the phagocytic index of the cells obtained from the non-treated control rabbits.
2. In the in vitro experiment, the enzymic activities and phagocytic index of PMN from blood of the CS-treated rabbits showed similar tendency to those of peritoneal PMN. The NBT test was found to be also decreased.
3. The release of lysosomal enzymes (A-P and β-G) from PMN of both the CS-treated and control animals rose sharply after the intravenous injection of live BCG cells, and the release of A-P attained its peak in one week and that of A-G in two weeks. However, the release of the lysosomal enzymes from PMN was inhibited by pretreatment of the animals with CS.
4. From these results, it was deduced that CS may stabilize the lysosomal membrane of PMN and Mφ and may reduce NADH oxidase activity both in vivo and in vitro. These facts may suggest that CS causes the lowering of growth-inhibiting and bactericidal actions on tubercle bacilli engulfed in PMN and Mφ. Thus, CS may be regarded to participate in the aggravation of induction and development of acute miliary tuberculosis in such a possible way.