Increased oxytocinergic system activity in the cardiac muscle in spontaneously hypertensive SHR rats

Agnieszka Wsol; Agata Gondek; Martyna Podobinska; Marek Chmielewski; Elżbieta Sajdel-Sułkowska; Agnieszka Cudnoch-Jędrzejewska

doi:10.5114/aoms.2019.85446

Increased oxytocinergic system activity in the cardiac muscle in spontaneously hypertensive SHR rats

Arch Med Sci. 2019 Jun 3;18(4):1088-1094. doi: 10.5114/aoms.2019.85446. eCollection 2022.

Authors

Agnieszka Wsol¹, Agata Gondek¹, Martyna Podobinska¹, Marek Chmielewski², Elżbieta Sajdel-Sułkowska^{1

3}, Agnieszka Cudnoch-Jędrzejewska¹

Affiliations

¹ Department of Experimental and Clinical Physiology, Laboratory of the Centre for Preclinical Research, Medical University of Warsaw, Warsaw, Poland.
² Chair and Department of Cardiology, Hypertension, and Internal Medicine, Medical University of Warsaw, Warsaw, Poland.
³ Department of Psychiatry, Harvard Medical School, Boston, Massachusetts, USA.

Abstract

Introduction: The present study aimed to determine whether the presence of cardiac hypertrophy due to arterial hypertension is associated with a change in the activity of the oxytocinergic system in cardiomyocytes.

Material and methods: The experiments were performed on male, spontaneously hypertensive rats (SHR, n = 10) and normotensive Wistar-Kyoto rats (WKY, n = 12). Blood samples were collected from both SHR and WKY animals to asses plasma oxytocin (OT) concentration; the rats were sacrificed by decapitation. Samples of the left and right ventricles were harvested for the analysis of the OT and oxytocin receptor (OTR) protein by ELISA, and OT and OTR mRNA expression by RT-PCR. Immunohistopathological studies were performed to confirm the presence of OTR receptors in the cardiac muscle of the ventricles.

Results: Plasma OT concentration did not differ between SHR and WKY rats. In the SHR rats, the expression of OT mRNA and the OT protein level was higher in the left and the right ventricle, while OTR mRNA expression was significantly lower in both the left and the right ventricle. However, the level of OTR protein was higher only in the left ventricle of the SHR rats. The presence of OTR receptors was confirmed by immunohistochemical analysis in the muscle of the right and left ventricle.

Conclusions: The presence of arterial hypertension is associated with increased activity of the oxytocinergic system in the heart, especially in the area of the left ventricle. These findings support the important role of this system in the maintenance of cardiovascular homeostasis.

Keywords: arterial hypertension; cardiac muscle; oxytocin; oxytocin receptor.