Meet Inspiring Speakers and Experts at our 3000+ Global Conference Series Events with over 1000+ Conferences, 1000+ Symposiums
and 1000+ Workshops on Medical, Pharma, Engineering, Science, Technology and Business.

Explore and learn more about Conference Series : World's leading Event Organizer

Back

Carlota Saldanha

University of Lisbon, Portugal

Title: Erythrocyte nitric oxide in glaucoma patients

Biography

Biography: Carlota Saldanha

Abstract

Erythrocyte or red blood cells (RBCs) are influents in the blood flow velocity and hemorheology. RBCs also participate in hemostasis systems and in body tissues oxygenation through the vessel endothelium. Endothelial cells and lymphocytes are able to synthesize acetylcholine (ACh) which is to release plasma. Depending on the endothelium integrity degree, the circulating ACh induce vasodilation or vasoconstriction according to the amount of nitric oxide (NO) synthesized and is released into smooth muscle cells (SMC) or to plasma. The NO released is scavenged by erythrocytes and blood cell free hemoglobin. NO enter into RBCs through its membrane protein band 3 and binds to oxyhemoglobin generating S-nitrosohemoglobin (SNO-Hb) and to glutathione originating nitrosoglutathione (GSNO). The NO efflux from erythrocyte is under dependence of mechanical or chemical stimuli bound to membrane receptors. Those affect the NO reservoir molecules inside erythrocyte in dependence of protein phosphorylation degree and redox thiol status. Timolol maleate is a compound used in treatment of patients with open angle glaucoma (OAG).Timolol is a weak inhibitor or erythrocyte membrane acetylcholinesterase (AChE) which behaves as an enzyme and a receptor of ACh. The erythrocytes obtained from blood samples of OAG patients’ present higher AChE enzyme activity and high NO efflux than those obtained from healthy persons. When blood samples taken from OAG patients were incubated in the presence of Ach, no changes in NO efflux in GSNO were verified. At variance, in  presence of timolol, instead of ACh, both NO efflux levels and GSNO concentration increase. These data evidences show that the erythrocyte membrane of OAG patients have different molecular properties than healthy subjects which corroborate the increasing tendency of RBCs to aggregate as observed in previous studies. The NO efflux signal transduction pathway associated to AChE-ACh (Figure) and AChE-timolol will be described at the conference.