Effects of a domain-selective ACE inhibitor in a mouse model of chronic angiotensin II-dependent hypertension

Burger, D., Reudelhuber, T. L., Mahajan, A., Chibale, K., Sturrock, E. D. and Touyz, R. M. (2014) Effects of a domain-selective ACE inhibitor in a mouse model of chronic angiotensin II-dependent hypertension. Clinical Science, 127(1), pp. 57-63. (doi: 10.1042/CS20130808)

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Abstract

The somatic isozyme of ACE (angiotensin I-converting enzyme) comprises two distinct zinc-dependent catalytic domains with different substrate specificities for angiotensin I (cleaved selectively by the C-domain) and bradykinin (cleaved equally efficiently by both the N- and C-domains). Classical ACEIs (ACE inhibitors) target both domains, with side effects such as cough and angio-oedema being attributed, in part, to N-domain inhibition, probably through bradykinin accumulation. We questioned whether a novel C-domain-selective ACEI (lisW-S) has anti-hypertensive effects without influencing bradykinin status. AngII (angiotensin II)-dependent hypertension was studied in mice that express active human renin in the liver (TtRhRen). Compared with wild-type littermates, TtRhRen mice displayed cardiac hypertrophy and had significantly elevated SBP [systolic BP (blood pressure)] as determined by tail cuff sphygmomanometry (150±3 compared with 112±5 mmHg; P<0.05) and telemetry (163±3 compared with 112±2 mmHg; P<0.01). Treatment with the non-selective ACEI lisinopril (1 mg/kg of body weight per day via an osmotic mini-pump for 2 weeks) reduced SBP (127±3 compared with. 154±6; P<0.05). Similarly, treatment with the C-domain selective ACEI lisW-S (lisinopril-tryptophan; 3.6 mg/kg of body weight per day via an osmotic mini-pump for 2 weeks) reduced BP. Treatment with lisinopril or lisW-S significantly reduced levels of AngII in kidneys (~4-fold; P<0.001). Ang-(2–8) [angiotensin-2–8)] was significantly reduced by lisinopril, but not by lisW-S. Plasma bradykinin levels were significantly increased only in the lisinopril group. These data suggest that C-domain-selective ACEIs reduce BP and AngII levels similarly to classical ACEIs. C-domain-selective ACEIs have the potential to avoid undesirable effects on the bradykinin system common to classic ACEIs and may represent a novel approach to the treatment of hypertension.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Touyz, Professor Rhian
Authors: Burger, D., Reudelhuber, T. L., Mahajan, A., Chibale, K., Sturrock, E. D., and Touyz, R. M.
College/School:College of Medical Veterinary and Life Sciences > Institute of Cardiovascular and Medical Sciences
Journal Name:Clinical Science
Publisher:Portland Press
ISSN:0143-5221
ISSN (Online):1470-8736

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