Erythrocyte Nitric Oxide in Patients with glaucoma ex vivo study Rita Esteves, Pedro Teixeira, Patrícia Napoleão, Carlos Neves, Carlota Saldanha June 2016

Nitric Oxide – Vascular Tonus and Hemorrheology Regulator After synthesis Diffuses to erythrocytes Diffuses to smooth muscle cells Herrmann et al, European Heart Journal, 2010

Nitric Oxide is Scavenged by Erythrocytes ACh NO efflux GSNO efflux Timolol less NO efflux less GSNO efflux Inibidor Saldanha et al, J Clin Exp Ophtalmol, 2013 Carvalho et al, J Membrane Biol, 2009

Nitric Oxide and Glaucoma Increased eNOS immunoreactivity in optic nerve head Primary open angle glaucoma Deregulation in ONH perfusion Lesions in optic nerve/blindness Overexpression of eNOS + nNOS Decreased levels of cGMP and nitrite Higher erythrocyte AChE activity Alterations in L-arginine/NO system Flemmer et al,Prog Retin Eye Res., 1998 Neufeld et al, Arch Ophtalmol, 1997 Polak et al, Arch Ophtalmol, 2007 Zabala et al, Eye (Lond), 1999

Nitric Oxide and Glaucoma Treatment: timolol IOP reduction beta-adrenergic receptors antagonist Inhibitor of erythrocyte AChE (Zabala 1999)

Objective Control ACh 10-5 M Timolol Heparinized venous blood Healthy subjects POAG patients Determine timolol effect in erythrocyte nitric oxide efflux and its metabolites in POAG patients NO efflux from erythrocyte [GSNO] in erythrocyte

Erythrocyte Nitric Oxide: Healthy Subjects vs Glaucoma patients Erythrocyte NO efflux in Healthy Subjects Erythrocyte NO efflux in POAG Patients * * N=18 N=15 Saldanha et al, J Clin Exp Ophtalmol, 2013

Erythrocyte Nitric Oxide: Healthy Subjects vs Glaucoma Patients Healthy subjects (N=18) Glaucoma patients (N=15) *p<0,5 vs healthy subjects

Erythrocyte GSNO: Healthy Subjects vs Glaucoma Patients Erythrocyte [GSNO] in Healthy Subjects Erythrocyte [GSNO] in POAG Patients * * * N=17 N=8

Erythrocyte GSNO: Healthy Subjects vs Glaucoma Patients Healthy subjects (N=17) Glaucoma patients (N=8)   *p<0,5 vs healthy subjects

Conclusions Erythrocyte of Glaucoma Patients vs Healthy Subjects increased NO bioavailability control timolol increased GSNO

Aknowledgements Carlota Saldanha Teresa Freitas Patrícia Napoleão C. Saldanha Lab