Effects of salt and stress on blood pressure parameters and antioxidant enzyme function in the heart and aorta of borderline hypertensive rats
2023
Authors:
Savić, BojanaBrkljačić, Jelena
Glumac, Sofija
Šarenac, Olivera
Murphy, David
Blagojević, Duško
Japundžić-Žigon, Nina
Oreščanin-Dušić, Zorana
Document Type:
Article (Published version)
Metadata
Show full item recordAbstract:
Hypertension and its complications are a leading cause of death in the human
population. Several factors can contribute to development of hypertension, such
as genetic predisposition, high salt intake and environmental stressors, underlying
oxidative stress as one of its key trademarks. We studied the effects of increased salt
intake and chronic stress on blood pressure parameters and the activity and protein
levels of antioxidant enzymes in the heart and aorta of borderline hypertensive rats
(BHRs) with genetic susceptibility to hypertension. All animals were randomized into
four groups: (1) Wistar rats kept in baseline conditions; (2) BHRs kept in baseline
conditions; (3) BHRs drinking 0.9% saline solution; and (4) BHRs drinking 0.9% saline
solution and exposed to repeated heterotypic stress. The BHRs exhibited significantly
higher blood pressure, mitochondrial superoxide dismutase (SOD2) and catalase (CAT)
protein levels and lower glutathione peroxidase (GPx) and glutathione reductase (GR)
activities in the aorta, followed by lower CAT and GPx protein levels and higher CAT
and GR activities in the heart, compared with normotensive Wistar rats. In the BHR
aorta, high salt intake elevated CAT and GPx activities, and when combined with stress
it increased GPx and GR activities. In BHR hearts, high salt intake provoked lower CAT
activity. Adding repeated stress to salt treatment further decreased CAT activity, in
addition to Cu2+–Zn2+ superoxide dismutase (SOD1) and GR activities. The protein
level of CAT was lower, whereas SOD2 and GPx increased. Overall, our results suggest
that BHR hearts are better adapted to oxidative pressure, compared with the aorta,
when exposed to salt and stress.
Keywords:
antioxidant enzymes; borderline hypertensive rats; hypertension; salt; stressSource:
Experimental Physiology, 2023, 108, 7, 946-960Funding / projects:
- Ministry of Science, Technological Development and Innovation of the Republic of Serbia, institutional funding - 200007 (University of Belgrade, Institute for Biological Research 'Siniša Stanković') (RS-MESTD-inst-2020-200007)
- Ministry of Science, Technological Development and Innovation of the Republic of Serbia, institutional funding - 200110 (University of Belgrade, Faculty of Medicine) (RS-MESTD-inst-2020-200110)
- Hypothalamic and medullary functional genomics in stress-induced hypertension (RS-MESTD-Integrated and Interdisciplinary Research (IIR or III)-41013)
- British Heart Foundation (grant numbers RG/11/28714 and FS/12/5/29339)
- Biotechnology and Biological Sciences Research Council (grant number BB/J005452/1)
DOI: 10.1113/EP090714
ISSN: 0958-0670
PubMed: 37128890