Effects of Tumour Cell Culture Supernatants on Some Biochemical Activities of Macrophages

Abstract

Summary The following enzyme activities were measured in cell lysates and supernatants from mouse peritoneal macrophages incubated with products of cultured tumour and other cells: acid phosphatase, β‐D‐glucuronidase, N‐acetyl‐D‐glucosaminidase, muramidase (lysozyme), lactic dehydrogenase (supernatant only) and plasminogen activator (supernatant only). There were no noteworthy changes in enzyme activities. Hydrogen peroxide production by appropriately stimulated mouse and/or guinea‐pig peritoneal exudate macrophages was variably inhibited by supernatants from some tumour cells and some normal cells. Changes in these biochemical activities of macrophages do not appear to be closely related to the anti‐inflammatory activity of tumour cell products.

Suppression of macrophage oxidative metabolism by products of malignant and nonmalignant cells.

“…Suppression of macrophage H202 release by TCM was recently described by Nelson et al (62). In that study, macrophages were only exposed overnight to conditioned media, which might explain why suppression was less consistently observed than in the present work.…”