HYPEROXIA STIMULATES NEWBORN SD RAT’S ALVEOLAR MACROPHAGE SECRETING
INTERLEUKIN 8
Zhang XH, Chang LW, Xia SW
Department
of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University
of Science and Technology, Wuhan, China
Objective: To investigate the role
of hyperoxia in newborn SD rat’s alveolar macrophage secreting interleukin
8 (IL-8).
Methods: We
use bronchoalveolar lavage (BAL) method to gain alveolar macrophages (AM)
from newborn SD rats. After purified, AM were randomly assigned to four
groups: group I (air group), group II (hyperoxia group) , group III (air
plus lipopolysaccharide (LPS) group), group IV (hyperoxia plus LPS group).
Group II and group IV were sealed and flushed the culture bottles with 100%
oxygen at 2L/min for 10min, then cultured 48 hours. Group III and group IV
were given LPS (10μg/ml) as soon as exposed to hyperoxia. Oxygen
concentration were test and supernatants were harvested after 48 hours
exposed. If the oxygen concentration <90%, the example was discarded.
L-lactate dehydrogenase (LDH) activity and IL-8 content of supernatants
were examined in all groups.
Results: After 48 hours exposed,
the LDH activity weren’t significant difference in all groups. IL-8 content
of supernatants were increased significantly in group II as compared with
group I(P<0.05), and it also increased significantly in group IV as
compared with group III (P<0.01). IL-8 content in group IV was highest
among four groups, group III followed, group II was lowest than those of
group III and group IV, but still higher than that of group I. There were
significant difference among four groups.
Conclusion: Hyperoxia alone or LPS
alone had stimulation to AM, while the latter was stronger, the combination
of hyperoxia and LPS had synergistic stimulation; IL-8 may play an
important role in hyperoxia lung injury, and AM may be an important source
of IL-8 in BAL fluid in vivo.