AJP - Lung Cellular and Molecular Physiology, Vol 268, Issue 5 781-L788, Copyright © 1995 by American Physiological Society
Neurokinin depletion attenuates pulmonary changes induced by antigen challenge in sensitized guinea pigs
P. Warth Mdo, E. A. Maldonado, S. M. Fernezlian, A. S. Leme, A. Perini, P. H. Saldiva and M. A. Martins
Departamento de Patologia, Faculdade de Medicina da Universidade de Sao Paulo, Brazil.
The role of neurokinins in the acute pulmonary response to antigen was
studied in guinea pigs that received ovalbumin (50 mg/kg ip) on days 1 and
3 and capsaicin (50 mg/kg sc) on day 21 (OAC); ovalbumin on days 1 and 3
(OA1); capsaicin on day 1 and OA on days 8 and 10 (COA); and ovalbumin on
days 8 and 10 (OA2). On day 28, guinea pigs were submitted to ovalbumin
aerosol challenge. Maximal values of pulmonary dynamic elastance (Edyn) and
pulmonary resistance (RL) were significantly lower in OAC and COA groups
compared with OA1 and OA2 groups (P < 0.001). There was no difference
between maximal Edyn and RL values obtained in OAC and COA groups.
Morphometric analysis of lungs showed significantly (P < 0.05) lower
values of contraction index of airways, peribronchial edema, and alveoli
over inflation in guinea pigs that received capsaicin compared with intact
guinea pigs. Capsaicin treatment did not influence the formation of
specific IgG1 anaphylactic antibodies. We conclude that neurokinin
depletion results in a decrease in the pulmonary mechanical and
inflammatory responses to antigen challenge in sensitized guinea pigs.
These effects are observed when capsaicin is given either before or after
sensitization.
