Primer ve Tekrarlayan Pteryjiumlarda Nitrik Oksid Sentaz Ekspresyonu

Pur po se: The aim of this study was to investigate the expression of different nitric oxide synthases (NOSs) in primary and recurrent\udpterygia and to investigate the probable role of any nitric oxide synthase on pterygium recurrence.\udMa te ri als and Met hod: Specimens of 40 primary pterygia and 10 recurrent pterygia excised during pterygium surgery were included in\udthe study. Also, 15 normal conjunctiva of medial limbus obtained from patients free of pterygia and removed during other ophthalmologic\udsurgeries formed the control group. Specimens were stained with hematoxylin and eosin for general histological and morphologic evaluation.\udThe distribution of n-NOS, e-NOS and i-NOS were analyzed using indirect immunoperoxidase staining.\udRe sults: Histological evaluation of specimens revealed that the epithelium in primary and recurrent pterygia groups was thicker compared\udto that in the control group. Immunohistochemical analysis revealed that in both primary pterygium and control groups, immunoreactivity\udwas positive for all NOSs in both epithelium and connective tissue. For recurrent pterygium group, NOS immunoreactivity could be\uddetected moderately for n-NOS in the epithelium and weakly for e-NOS in both epithelium and connective tissue. However, in recurrent\udpterygium samples, i-NOS immunoreactivity was lacking in both epithelium and connective tissue.\udDis cus si on: These data are the first to demonstrate that NOS expression may differ between primary and recurrent pterygia. Meanwhile,\udcontinuous expression of n-NOS with suppression of i-NOS and e-NOS may be an important step in the recurrence process of pterygia.\ud(Turk J Ophthalmol 2012; 42: 166-71