Is airway hyper-responsiveness in allergic asthma in guinea-pigs mediated by nerve growth factor via the induction of substance P : a potential role for trkA?
We conclude that substance P plays a role in the induction of AHR in our model for allergic asthma which is most likely mediated by NGF. As both tyrosine kinase inhibitors AG879 and K252a show a similar inhibitory effect on airway function after allergen challenge, although both tyrosine kinase inhibitors exhibit different non-specific inhibitory effects on targets other than trkA tyrosine kinases, it is likely that the induction of substance P derived from sensory nerves is mediated by NGF via its high-affinity receptor trkA.
Thickening of nerves is compatible with changes in the myelin sheath structure, whereas lowered AD values suggest axonal dysfunction. These findings suggest that myelin and axons are diffusely involved in MMN pathogenesis.