Short-term exposure to dexamethasone promotes autonomic imbalance to the heart before hypertension

• Autor(a) principal: Duchatsch, Francine [UNESP]
• Data de Publicação: 2018
• Outros Autores: Constantino, Paula B. [UNESP], Herrera, Naiara A. [UNESP], Fabrício, Mayara F. [UNESP], Tardelli, Lidieli P. [UNESP], Martuscelli, Aline M. [UNESP], Dionísio, Thiago J., Santos, Carlos F., Amaral, Sandra L. [UNESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1016/j.jash.2018.06.004; http://hdl.handle.net/11449/177153
• topic: Autonomic nervous system; blood pressure; glucocorticoids

Hypertension is one of the chronic side effects of dexamethasone (DEX) treatment; however, almost nothing is known about its acute effects. Therefore, the aim of this study was to investigate the possible mechanisms involved in blood pressure control after acute or short-term DEX treatment in adult animals. Eighty Wistar rats were divided into four groups: C1 and C5, for rats treated with saline for 1 or 5 days, respectively; D1 and D5, for rats treated with DEX for 1 or 5 days, respectively (decadron, 1 mg/kg, i.p.). Heart rate was increased in DEX treatment, but arterial pressure and cardiac muscle mass were not altered. Only few and isolated changes on gene expression and protein level of renin-angiotensin system components were observed. Five days of DEX treatment, but not one day, determined an increase in sympathetic component of spectral analysis (+75.93%, P <.05) and a significant reduction of parasympathetic component (–18.02%, P <.05), which contributed to the autonomic imbalance to the heart (LF/HF, +863.69%). The results of this present study demonstrated, for the first time, that short-term exposure to DEX treatment impairs the autonomic balance to the heart before hypertension, which was independent of renin-angiotensin system.