AIM: To characterise the influence of endothelin-1 (ET-1), a vasoactive peptide, and its receptors (endothelin B (ETB) and endothelin A (ETA)) on rat optic nerve head astrocyte (ONHA) proliferation. METHODS: ONHAs were isolated from adult Brown Norway rats. ONHA specificity was determined with immunohistochemistry for: glial fibrillary acidic protein (GFAP); A2B5, a marker of type II astrocytes located outside the ONH; and myelin basic protein (MBP). ONHA proliferation was quantified following treatment with ET-1 (1x10(-6), 1x10(-7), 1x10(-9) or 1x10(-11) M) or vehicle for 24, 48 or 72 h. ETB and ETA antagonists were used to assess the role of each receptor in ONHA proliferation. RESULTS: ONHA specificity was confirmed with positive labelling for GFAP, and negative labelling for A2B5 and MBP. ONHAs also expressed ETB and ETA. Cell percentages increased significantly beginning 48 h after ET-1 exposure with 1x10(-7) (20%) and 1x10(-9) M (15%). After 72 h, ONHA percentages increased significantly at all ET-1 concentrations (25%, 21%, 29%, 28% increases relative to vehicle, for 1x10(-6), 1x10(-7), 1x10(-9) and 1x10(-11) M, respectively). No significant proliferation occurred in the presence of either antagonist. CONCLUSION: ONHAs proliferated following 48 h or more of exposure to ET-1. The proliferation required both ETB and ETA receptors.
AIM: To characterise the influence of endothelin-1 (ET-1), a vasoactive peptide, and its receptors (endothelin B (ETB) and endothelin A (ETA)) on rat optic nerve head astrocyte (ONHA) proliferation. METHODS: ONHAs were isolated from adult Brown Norway rats. ONHA specificity was determined with immunohistochemistry for: glial fibrillary acidic protein (GFAP); A2B5, a marker of type II astrocytes located outside the ONH; and myelin basic protein (MBP). ONHA proliferation was quantified following treatment with ET-1 (1x10(-6), 1x10(-7), 1x10(-9) or 1x10(-11) M) or vehicle for 24, 48 or 72 h. ETB and ETA antagonists were used to assess the role of each receptor in ONHA proliferation. RESULTS: ONHA specificity was confirmed with positive labelling for GFAP, and negative labelling for A2B5 and MBP. ONHAs also expressed ETB and ETA. Cell percentages increased significantly beginning 48 h after ET-1 exposure with 1x10(-7) (20%) and 1x10(-9) M (15%). After 72 h, ONHA percentages increased significantly at all ET-1 concentrations (25%, 21%, 29%, 28% increases relative to vehicle, for 1x10(-6), 1x10(-7), 1x10(-9) and 1x10(-11) M, respectively). No significant proliferation occurred in the presence of either antagonist. CONCLUSION: ONHAs proliferated following 48 h or more of exposure to ET-1. The proliferation required both ETB and ETA receptors.
Authors: Marta Pazos; Hongli Yang; Stuart K Gardiner; William O Cepurna; Elaine C Johnson; John C Morrison; Claude F Burgoyne Journal: Exp Eye Res Date: 2015-10-22 Impact factor: 3.467
Authors: Malia M Edwards; D Scott McLeod; Rhonda Grebe; Céline Heng; Olivier Lefebvre; Gerard A Lutty Journal: BMC Dev Biol Date: 2011-10-14 Impact factor: 1.978
Authors: Alena Z Minton; Nitasha R Phatak; Dorota L Stankowska; Shaoqing He; Hai-Ying Ma; Brett H Mueller; Ming Jiang; Robert Luedtke; Shaohua Yang; Colby Brownlee; Raghu R Krishnamoorthy Journal: PLoS One Date: 2012-08-20 Impact factor: 3.240