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Journal of Ophthalmology
Volume 2012, Article ID 498565, 6 pages
http://dx.doi.org/10.1155/2012/498565
Research Article

Modulation of Vasomotive Activity in Rabbit External Ophthalmic Artery by Neuropeptides

1Clinical Department, CIISA, Faculty of Veterinary Medicine, Technical University of Lisbon, Alameda da Universidade Técnica, 1300-477 Lisbon, Portugal
2Instituto de Medicina Molecular and Instituto de Fisiologia, Faculdade de Medicina, Universidade de Lisboa, Avenida Professor Egas Moniz, 1649-028 Lisbon, Portugal

Received 8 August 2011; Revised 1 November 2011; Accepted 3 November 2011

Academic Editor: Shintaro Nakao

Copyright © 2012 Esmeralda Sofia Costa Delgado et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Purpose. To investigate the vasomotive activity upon the external ophthalmic artery of vasointestinal peptide (VIP) and neuropeptide Y (NPY) using a previously developed model. Methods. Isolated rabbit eyes ( 𝑛 = 1 2 ) were perfused in situ with tyrode through the external ophthalmic artery. Effects of intra-arterial injections of NPY 200 μg/ml (Group A; 𝑛 = 6 ) and VIP 200 μg/ml (Group B; 𝑛 = 6 ) on the recorded pressure were obtained. For statistical analysis, Student's paired t-test and Fast Fourier Transform were used. Results. Spontaneous oscillations were observed before any drug administration in the 12 rabbit models. NPY produced an increase in total vascular resistance and a higher frequency and amplitude of oscillations, while VIP evoked the opposite effects. Conclusions. This study provides evidence of vasomotion in basal conditions in rabbit external ophthalmic artery. Concerning drug effects, NPY increased arterial resistance and enhanced vasomotion while VIP produced opposite effects which demonstrates their profound influence in arterial vasomotion.