Studies on thiol proteinase inhibitors in rat peripheral blood cells

The concentrations of two types of endogenous thiol proteinase inhibitors, TPI-alpha and TPI-beta, in rat peripheral blood cells were determined by sensitive immunoassay methods. The concentration of TPI-alpha was highest in neutrophils among the peripheral blood cells tested. On the contrary, the concentration of TPI-beta was highest in macrophages followed in order by neutrophils, lymphocytes and erythrocytes. The serum level of TPI-beta was 47 times that of TPI-alpha. Immunohistochemical studies showed that in rat liver, TPI-beta was localized in Kupfer cells, and that only little TPI-alpha was present in liver tissue.