Pregnancy and oestrogen regulate sinoatrial node calcium homeostasis and accelerate pacemaking.

ABSTRACT: Aims:During pregnancy, there is a significant increase in heart rate (HR) potentially associated with an increased risk of arrhythmias or exacerbation of pre-existing cardiac conditions endangering both mother and foetus. Calcium homeostasis plays an important role in regulating automaticity of the sinoatrial node (SAN); however, its contribution to the accelerated HR during pregnancy remains unknown. Methods and results:Using murine SAN cells, we showed that pregnancy increased L-type Ca2+ current (ICaL) and CaV1.3 mRNA expression, whereas T-type Ca2+ current (ICaT) and its underlying channel were unchanged. Analysis of SAN intra-cellular Ca2+ oscillations showed that the rate of spontaneous Ca2+ transients was significantly higher in pregnant mice along with a higher mRNA expression of r

SUBMITTER: El Khoury N 

PROVIDER: S-EPMC6148331 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature