Differential effects of dexamethasone on arterial stiffness, myocardial remodeling and blood pressure between normotensive and spontaneously hypertensive rats

Author(s)

Tardelli, Lidieli P. ^[1] ; Duchatsch, Francine ^[1] ; Herrera, Naiara A. ^[1] ; Vicentini, Carlos Alberto ^[2] ; Okoshi, Katashi ^[3] ; Amaral, Sandra L. ^{[4, 1]}

Affiliation

^[1] PIPGCF UFSCar UNESP, Joint Grad Program Physiol Sci, Sao Carlos - Brazil

^[2] Sao Paulo State Univ UNESP, Sch Sci, Dept Biol, Bauru, SP - Brazil

^[3] Sao Paulo State Univ UNESP, Botucatu Med Sch, Dept Med Clin, Botucatu, SP - Brazil

^[4] Sao Paulo State Univ Unesp, Sch Sci, Dept Phys Educ, Bauru, SP - Brazil

• Document type: Journal article
• Source: JOURNAL OF APPLIED TOXICOLOGY; v. 41, n. 10, p. 1673-1686, OCT 2021.
• Web of Science Citations: 1

Abstract

Dexamethasone (DEX)-induced hypertension is observed in normotensive rats, but little is known about the effects of DEX on spontaneously hypertensive animals (SHR). This study aimed to evaluate the effects of DEX on hemodynamics, cardiac hypertrophy and arterial stiffness in normotensive and hypertensive rats. Wistar rats and SHR were treated with DEX (50 mu g/kg s.c., 14 d) or saline. Pulse wave velocity (PWV), echocardiographic parameters, blood pressure (BP), autonomic modulation and histological analyses of heart and thoracic aorta were performed. SHR had higher BP compared with Wistar, associated with autonomic unbalance to the heart. Echocardiographic changes in SHR (vs. Wistar) were suggestive of cardiac remodeling: higher relative wall thickness (RWT, +28%) and left ventricle mass index (LVMI, +26%) and lower left ventricle systolic diameter (LVSD, -19%) and LV diastolic diameter (LVDD, -10%), with slightly systolic dysfunction and preserved diastolic dysfunction. Also, SHR had lower myocardial capillary density and similar collagen deposition area. PWV was higher in SHR due to higher aortic collagen deposition. DEX-treated Wistar rats presented higher BP (similar to 23%) and autonomic unbalance. DEX did not change cardiac structure in Wistar, but PWV (+21%) and aortic collagen deposition area (+21%) were higher compared with control. On the other side, DEX did not change BP or autonomic balance to the heart in SHR, but reduced RWT and LV collagen deposition area (-12% vs. SHRCT). In conclusion, the results suggest a differential effect of dexamethasone on arterial stiffness, myocardial remodeling and blood pressure between normotensive and spontaneously hypertensive rats. (AU)

• FAPESP's process: 18/00567-4 - Influence of empaglifozin on the heart of rats with myocardial infarction-induced cardiac remodeling
• Grantee: Katashi Okoshi
• Support Opportunities: Regular Research Grants
• FAPESP's process: 16/12532-5 - Exercise training effects on SHR treated with dexamethasone: role of miRNAs
• Grantee: Naiara Araújo Herrera
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 17/00509-1 - Role of physical training on autonomic balance, arterial stiffness and rarefaction in spontaneously hypertensive rats treated with dexamethasone: role of miRNA
• Grantee: Sandra Lia do Amaral Cardoso
• Support Opportunities: Regular Research Grants
• FAPESP's process: 17/14405-3 - Influence of aerobic physical training on cardiac remodeling of spontaneously hypertensive rats treated with dexamethasone
• Grantee: Francine Duchatsch Ribeiro de Souza
• Support Opportunities: Scholarships in Brazil - Master