Release of lysosomal enzymes is not correlated with superoxide and prostaglandin production by stimulated rat Kupffer cells in primary culture.

A substantial production of prostaglandin E2 (PGE2) was induced in primary cultures of rat Kupffer cells by zymosan, calcium ionophore A23187, phorbol ester and arachidonic acid, whereas contact with latex particles, glucan or immunocomplexes led to a minor PGE2 release only. Superoxide generation, on the other hand, was observed after administration of zymosan, glucan and the phorbol ester but not after treatment with the calcium ionophore, arachidonate, latex particles or immunocomplexes. Lysosomal enzymes like beta-glucuronidase and N-acetyl-beta-D-glucosaminidase were detected in the medium of rat Kupffer cells in primary culture after contact with zymosan or calcium ionophore A23187. Other particulate matter, e.g., latex particles, glucan and immunocomplexes, lipopolysaccharides or soluble agents such as phorbol ester, arachidonic acid and gamma-interferon did not provoke the release of lysosomal enzymes. The activities of beta-glucuronidase and N-acetyl-beta-D-glucosaminidase found following prolonged exposure to zymosan or to A23187 were accompanied by the appearance of typical cytosolic enzymes like lactate dehydrogenase and glucose-6-phosphate dehydrogenase in similar proportions and with the same time course. The release of lysosomal enzymes seen after administration of zymosan or calcium ionophore is thought to be the result of unspecific leakage rather than a specific response of elicited Kupffer cells.