Emerging Roles of Angiotensin-Converting Enzyme 2(ACE2)/Angiotensin-(1-9)[Ang-(1-9)] Axis in Hypertension Related Kidney Disease

Volume 28 , Issue 1 , June 2026 , Pages 43-59

Authors

Sima Mohammed 1 ; Ridha Hussein 1

1 University of Sulaimani, College of Science, Department of Biology

DOI logo 10.17656/sujpas.1137

Keywords

Abstract

The Renin-Angiotensin System (RAAS) is a crucial regulator of blood pressure and kidney function. This study aimed to elucidate the role of key components of this system by evaluating their circulating concentrations and tissue expression patterns using enzyme-linked immunosorbent assay and quantitative polymerase chain reaction, with samples recruited from Shar and Ferkary Hospitals. A total of 90 blood samples were collected from three groups: controls, participants with kidney disease without hypertension (non-HTN-CKD), and participants with hypertensive kidney disease (HTN-CKD). In addition, 23 kidney biopsies were collected from participants at Shar Hospital; 13 of the participants had kidney disease associated with hypertension, whereas the remaining 10 had kidney disease without hypertension. Circulating Ang-(1-9) levels were markedly increased in patients with HTN-CKD (988.5±143.4) compared with those in the control group (716.3±288.0; P-value < 0.0001). In contrast, Angiotensin Converting Enzyme (ACE) concentrations were significantly lower in HTN-CKD patients (49.38±10.80) compared to the control group (70.74±21.73; p < 0.0001). While circulating ACE2 concentrations (mean ± SD) were as follows: HTN-CKD, 1.859±0.4646; non-HTN-CKD, 1.683±0.3397; control, 1.956±0.5467. In conclusion, these findings suggest that ACE2 plays a limited role in hypertensive kidney disease. In contrast, elevated Ang-(1-9) levels appear to be significantly associated with hypertension and kidney disease. In conclusion, further research with a larger sample size and investigation of additional RAAS components and related pathways is needed to better understand the role of this pathway.

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