
Development of nonfibrotic left ventricular hypertrophy in an ANG II‐induced chronic ovine hypertension model
Author(s) -
Klatt Niklas,
Scherschel Katharina,
Schad Claudia,
Lau Denise,
Reitmeier Aline,
Kuklik Pawel,
Muellerleile Kai,
Yamamura Jin,
Zeller Tanja,
Steven Daniel,
Baldus Stephan,
Schäffer Benjamin,
Jungen Christiane,
Eickholt Christian,
Wassilew Katharina,
Schwedhelm Edzard,
Willems Stephan,
Meyer Christian
Publication year - 2016
Publication title -
physiological reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.918
H-Index - 39
ISSN - 2051-817X
DOI - 10.14814/phy2.12897
Subject(s) - medicine , left ventricular hypertrophy , cardiology , fibrosis , muscle hypertrophy , angiotensin ii , blood pressure , magnetic resonance imaging , myocardial fibrosis , ventricular remodeling , heart failure , radiology
Hypertension is a major risk factor for many cardiovascular diseases and leads to subsequent concomitant pathologies such as left ventricular hypertrophy ( LVH ). Translational approaches using large animals get more important as they allow the use of standard clinical procedures in an experimental setting. Therefore, the aim of this study was to establish a minimally invasive ovine hypertension model using chronic angiotensin II ( ANG II ) treatment and to characterize its effects on cardiac remodeling after 8 weeks. Sheep were implanted with osmotic minipumps filled with either vehicle control ( n = 7) or ANG II ( n = 9) for 8 weeks. Mean arterial blood pressure in the ANG II ‐treated group increased from 87.4 ± 5.3 to 111.8 ± 6.9 mmHg ( P = 0.00013). Cardiovascular magnetic resonance imaging showed an increase in left ventricular mass from 112 ± 12.6 g to 131 ± 18.7 g after 7 weeks ( P = 0.0017). This was confirmed by postmortem measurement of left ventricular wall thickness which was higher in ANG II ‐treated animals compared to the control group (18 ± 4 mm vs. 13 ± 2 mm, respectively, P = 0.002). However, ANG II ‐treated sheep did not reveal any signs of fibrosis or inflammatory infiltrates as defined by picrosirius red and H&E staining on myocardial full thickness paraffin sections of both atria and ventricles. Measurements of plasma high‐sensitivity C‐reactive protein and urinary 8‐iso‐prostaglandin F 2 α were inconspicuous in all animals. Furthermore, multielectrode surface mapping of the heart did not show any differences in epicardial conduction velocity and heterogeneity. These data demonstrate that chronic ANG II treatment using osmotic minipumps presents a reliable, minimally invasive approach to establish hypertension and nonfibrotic LVH in sheep.