EFFECT OF GROUP A STREPTOCOCCAL PEPTIDOGLYCAN AND GROUP A STREPTOCOCCAL CELL-WALL ON BONE IN TISSUE-CULTURE

The effects of the peptidoglycan and cell wall on mouse calvaria in tissue culture were investigated. Viability of the cultured bone was shown by autoradiographs demonstrating [14C]-proline uptake, and by cytochrome oxidase staining of cultured bone indicating oxidative metabolism in mitochondria at the time of fixation. The effects of the two agents were evaluated by [14C]-proline uptake and 45Ca release. A single 250 μg dose and multiple 250μg doses of peptidoglycan caused a 20 per cent and a 28 per cent reduction in [14C]-proline uptake, respectively (p < 0.05). One 500 μg dose of cell wall caused a 36 per cent reduction (p < 0.01). A single 250 μg dose of peptidoglycan had no significant effect on 45Ca release, and multiple 250 μg doses of peptidoglycan caused a 104 per cent increase in 45Ca release (p < 0.1). One 500 μg dose of cell wall caused a 175 per cent increase in 45Ca release (p < 0.001). These trends suggest that Group A streptococcal cell wall inhibits synthesis of organic components of bone and induces bone resorption in vitro, and that Group A streptococcal peptidoglycan is the active constituent with respect to inhibition of synthesis of the organic component. © 1979.