Pregnancy Increases Ca²⁺ Sparks/Spontaneous Transient Outward Currents and Reduces Uterine Arterial Myogenic Tone.

ABSTRACT: Spontaneous transient outward currents (STOCs) at physiological membrane potentials of vascular smooth muscle cells fundamentally regulate vascular myogenic tone and blood flow in an organ. We hypothesize that heightened STOCs play a key role in uterine vascular adaptation to pregnancy. Uterine arteries were isolated from nonpregnant and near-term pregnant sheep. Ca²⁺ sparks were measured by confocal microscopy, and STOCs were determined by electrophysiological recording in smooth muscle cells. Percentage of Ca²⁺ spark firing myocytes increased dramatically at the resting condition in uterine arterial smooth muscle of pregnant animals, as compared with nonpregnant animals. Pregnancy upregulated the expression of RyRs (ryanodine receptors) and significantly boosted Ca<

SUBMITTER: Hu XQ 

PROVIDER: S-EPMC6374197 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature