Abstract
We previously reported that mouse macrophages became easily permeable to phosphoric esters and nucleotides by the in vitro treatment with external ATP. To study in vivo effects of ATP, the functional properties of peritoneal macrophages in intraperitoneal ATP-injected mouse were investigated. The macrophages at 5 hr after the ATP injection exerted low activity of ecto-5'-nucleotidase, suggesting exudate macrophages not resident macrophages. At 18 hr and 4 days, the peritoneal macrophages also showed low activities of the enzyme. Moreover, those macrophages had high oxygen radical formations and inhibited cytostatically growth of Salmonella bacteria. In contrast, thioglycollate, proteose·peptone and LPS are well known to induce peritoneal exudate macrophages, and also showed high oxygen radical formations and antimicrobial activities as similar as one of ATP. These stimulatives, however, did not induce the permeability change of macrophages in vitro. By the administration of macrophages which were experienced in the permeability change in vitro with ATP treatment, the similar macrophages as those obtained from the in vivo ATP direct injection appeared in the peritoneal exudate cells. From these results, it is possible to speculate that the permeability change of macrophages and then the induction of exudate macrophages occur in vivo, when a large quantity of external ATP would be locally present.
