VCAM-1 expression, eosinophil infiltration, and pharmacological modulation in rat allergic airway inflammation.
Abstract
AIM: To determine vascular cell adhesion molecule-1 (VCAM-1) expression and
eosinophil infiltration in the lungs of the rats with allergic airway
inflammation, and their possible modulation by dexamethasone and neurokinin-1
receptor antagonist SR140333.
METHODS: Sensitized rats were challenged with inhalation of 1 % ovalbumin
aerosol. Protein expression of VCAM-1 in the lungs and eosinophil infiltration
around bronchi in different groups were determined 24 h after challenge. SR140333
(0.01 and 0.10 mg/kg) and dexamethasone (0.50 mg/kg) were injected ip, twice a
day, for 3 d before challenge.
RESULTS: The expression of VCAM-1 was increased in the sensitized rat lungs as
compared with the non-sensitized rats (P<0.05). The increment was inhibited by
pretreatment with dexamethasone (P<0.05), but not with SR140333 (P>0.05). On the
other hand, antigen challenge in sensitized rats evoked eosinophil infiltration
(P<0.05) but no further increase in VCAM-1 expression (P>0.05). Furthermore,
SR140333 inhibited eosinophil infiltration (P<0.05) but had no effect on VCAM-1
expression (P>0.05), whereas dexamethasone inhibited both responses (P<0.05).
CONCLUSION: The expression of VCAM-1 increases during antigen sensitization in
rat lungs, and dexamethasone and SR140333 may inhibit allergic airway
inflammation in different mechanisms.
Keywords:
eosinophil infiltration in the lungs of the rats with allergic airway
inflammation, and their possible modulation by dexamethasone and neurokinin-1
receptor antagonist SR140333.
METHODS: Sensitized rats were challenged with inhalation of 1 % ovalbumin
aerosol. Protein expression of VCAM-1 in the lungs and eosinophil infiltration
around bronchi in different groups were determined 24 h after challenge. SR140333
(0.01 and 0.10 mg/kg) and dexamethasone (0.50 mg/kg) were injected ip, twice a
day, for 3 d before challenge.
RESULTS: The expression of VCAM-1 was increased in the sensitized rat lungs as
compared with the non-sensitized rats (P<0.05). The increment was inhibited by
pretreatment with dexamethasone (P<0.05), but not with SR140333 (P>0.05). On the
other hand, antigen challenge in sensitized rats evoked eosinophil infiltration
(P<0.05) but no further increase in VCAM-1 expression (P>0.05). Furthermore,
SR140333 inhibited eosinophil infiltration (P<0.05) but had no effect on VCAM-1
expression (P>0.05), whereas dexamethasone inhibited both responses (P<0.05).
CONCLUSION: The expression of VCAM-1 increases during antigen sensitization in
rat lungs, and dexamethasone and SR140333 may inhibit allergic airway
inflammation in different mechanisms.