Le. Sampson et Dj. Chaplin, THE INFLUENCE OF OXYGEN AND CARBON-DIOXIDE TENSION ON THE PRODUCTION OF TNF-ALPHA BY ACTIVATED MACROPHAGES, British Journal of Cancer, 74, 1996, pp. 133-135
The influence of oxygen tension and carbon dioxide levels on human TNF
alpha (hTNF alpha) production by the monocyte/macrophage cell line U9
37 has been examined. The cells were stimulated under different oxygen
and carbon dioxide concentrations in the presence and absence of the
known TNF alpha inducer phorbol 12-myristate 13-acetate (PMA). The res
ults indicated that U937 cells stimulated with PMA produced up to 10 t
imes more TNF alpha when incubated under tumour-relevant oxygen tensio
ns of 1% rather than under aerobic conditions, i.e. 21% O-2. Increasin
g the carbon dioxide levels from 5% to 7% however decreased the amount
of PMA-stimulated hTNF alpha produced. No hTNF alpha was produced in
the unstimulated U937 cells, indicating that low oxygen tensions (hypo
xia) alone did not induce the production of TNF alpha, in this case.