Angiotensin(1-7) and ACE2, “The Hot Spots” of Renin-Angiotensin System, Detected in the Human Aqueous Humor
Mervi Holappa 1, Jarkko Valjakka 1, Anu Vaajanen*, 2, 3
Identifiers and Pagination:Year: 2015
First Page: 28
Last Page: 32
Publisher ID: TOOPHTJ-9-28
Article History:Received Date: 30/12/2014
Revision Received Date: 2/3/2015
Acceptance Date: 2/3/2015
Electronic publication date: 31 /3/2015
Collection year: 2015
open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.
The main purpose of the study was to establish whether essential components of the renin-angiotensin system (RAS) exist in the human aqueous humor.
Forty-five patients ≥ 60 (74±7) years of age undergoing cataract surgery at Tampere University Hospital were randomly selected for the prospective study. The exclusion criterion was the use of oral antihypertensive medicine acting via renin-angiotensin system. Aqueous humor samples were taken at the beginning of normal cataract extraction. The samples were frozen and stored at -80 °C. The concentrations of intraocular endogenous RAS components Ang(1-7), ACE2, and ACE1 were measured using ELISA.
Concentration medians of Ang(1-7), ACE2, and ACE1 in the aqueous humor were: Ang(1-7) 4.08 ng/ml, ACE2 2.32 ng/ml and ACE1 0.35 ng/ml. The concentrations were significantly higher in glaucomatous than in non-glaucomatous eyes, ACE1 (p=0.014) and Ang(1-7) (p=0.026) vs non-glaucomatous eyes.
Ang(1-7), ACE2 and ACE1 are found in the human aqueous humor. The observations are consistent with the conception that local tissue-RAS exists in the human eye and it might have a role in the control of intraocular pressure.