NEUTROPHIL CATHEPSIN-G IS SPECIFICALLY DECREASED UNDER VITAMIN-A-DEFICIENCY

Vitamin A deficiency leads to an increased susceptibility to infection s, increased severity of infections and increased mortality. Because t he neutrophil is the first cell to respond to infection, this study ex plores the effect of vitamin A deficiency on neutrophil proteinases. W e found that neutrophils from vitamin A-deficient rats had lower level s of two cathepsin G-like enzymes (28 and 24 kDa) when compared to neu trophils from weight-matched pair-fed rats, vitamin A-deficient rats w hich were repleted with retinyl palmitate and nonrestricted vitamin A complete diet rats. The 28 kDa cathepsin G-like enzyme, which migrated with the same mobility as elastase on SDS-polyacrylamide gels, was qu antified using Western blots. The 24 kDa cathepsin G-like enzyme was q uantified using zymogram gels. This activity was inhibited by chymosta tin. Other neutrophil proteinases, elastase, plasminogen activators an d gelatinase, were not altered significantly by vitamin A deficiency. The low levels of cathepsin G may contribute to differences in the inf lammatory process observed under vitamin A deficiency.