Capsaicin-sensitive nerves and neurokinins modulate non-neuronal nNOS expression in lung.
We investigated the effects of substance P (SP) and neurokinin A (NKA) infusion and acute stimulation of capsaicin-sensitive sensory nerves fibers (CAP) on lung recruitment of neuronal nitric oxide synthase (nNOS)-positive inflammatory and respiratory epithelial (RE) cells in guinea-pigs. We evaluated if the effects of CAP stimulation were maintained until 14 days and had functional pulmonary repercussions. After 24h of CAP and 30 min after SP and NKA infusions there was an increase in nNOS-positive eosinophils and mononuclear cells compared to controls (P<0.05). SP group presented an increase in nNOS-positive RE (P<0.05). After 14 days of CAP stimulation, there was a reduction in resistance (R(rs)) and elastance (E(rs)) of respiratory system in capsaicin pre-treated animals. We noticed a correlation between nNOS-positive eosinophils (R=-0.644, P<0.05) and mononuclear cells (R=-0.88, P<0.001) and R(rs). Concluding, CAP and neurokinins increase nNOS expression by inflammatory and RE cells. The increase in nNOS expression induced by low and high doses stimulation of CAP is longstanding and correlated to pulmonary mechanical repercussions.
Prado
Carla M
CM
Department of Medicine, School of Medicine, University of São Paulo, São Paulo, Brazil. cprado8@yahoo.com.br
Leick-Maldonado
Edna A
EA
Miyamoto
Luciana
L
Yano
Larissa M
LM
Kasahara
David I
DI
Martins
Mílton A
MA
Tibério
Iolanda F L C
IF
D000403:Airway Resistance / Q000502:physiology; D000465:Algorithms; D000818:Animals; D002211:Capsaicin / Q000494:pharmacology*; D004804:Eosinophils / Q000187:drug effects / Q000201:enzymology; D004847:Epithelial Cells / Q000187:drug effects / Q000201:enzymology; D006168:Guinea Pigs; D007150:Immunohistochemistry; D008168:Lung / Q000201:enzymology* / Q000294:innervation / Q000502:physiology*; D008297:Male; D009000:Monocytes / Q000187:drug effects / Q000201:enzymology; D015288:Neurokinin A / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D052248:Nitric Oxide Synthase Type I / Q000096:biosynthesis*; D015656:Respiratory Mechanics / Q000502:physiology; D020545:Respiratory Mucosa / Q000187:drug effects / Q000201:enzymology
D015288:Neurokinin A; D052248:Nitric Oxide Synthase Type I; D002211:Capsaicin