New Treatments: Targeting Neuropeptides

NPY

In January of 2011, a study was conducted by researchers Sacchetti, Micera, Lambiase, Speranza, Mantelli, Petrachi and Bonini from the Department of Ophthalmology at the University of Rome and published in Molecular Vision. The study focused on the role of neuropeptides in the inflammatory response associated with allergic conjunctivitis. Neuropeptides are molecules that work with mediators to increase or decrease their effects. For example, when the neuropeptide NPY is released in conjunction with norepinephrine, it amplifies the vasoconstriction or squeezing of blood vessels produced by norepinephrine. In the case of allergies, neuropeptides may play a role in increasing the effects of mediators used in the inflammatory response. For example, neuropeptides may be released along with histamine, producing an increased inflammatory response that would not be seen if histamine were released by itself.

In the study, researchers sought to measure levels of neuropeptides in the tears of patients with allergic conjunctivitis and those without. If there were more neuropeptides in the tears of allergic conjunctivitis patients, it is likely that neuropeptides play a role in the inflammatory response. A conjunctival provocation test (CPT) was used to measure the allergic response of fifteen patients with allergic conjunctivitis and ten patients without allergic conjunctivitis. This served as a control because the patients with no allergic response should have a very low CPT score. Then tear samples were collected from all patients and the amount of neuropeptides VIP, NPY, CGRP and SP were measured.

The researchers found that the concentration of VIP, CGRP and SP neuropeptides were higher in the tears of allergic conjunctivitis patients. However, there was no significant difference in the number of NPY neuropeptides in the allergic conjunctivitis and non-allergic patients. However, this evidence suggests that neuropeptides may play a role in increasing the effects of mediators involved in the inflammatory response. More research needs to be done to identify that role. If researchers succeed, this opens up another avenue for treatment. For example, inhibiting the binding of neuropeptides or blocking their release, can decrease the effects of neuropeptides and maybe decrease the effects of inflammatory mediators like histamine. It will be interesting to see how this area of research develops in the future.

If you are looking for a new way to approach allergic conjunctivitis, discuss recent developments in neuropeptide research with your healthcare provider.