El-Lakany Mohammed A, Welsh Donald G
Department of Physiology & Pharmacology, Robarts Research Institute, Schulich School of Medicine, University of Western Ontario, London, ON, Canada.
Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt.
Front Physiol. 2024 Feb 28;15:1374730. doi: 10.3389/fphys.2024.1374730. eCollection 2024.
Arterial networks are controlled by the consolidated output of stimuli that set "how much" (magnitude) and "where" (distribution) blood flow is delivered. While notable changes in magnitude are tied to network wide responses, altered distribution often arises from focal changes in tone, whose mechanistic foundation remains unclear. We propose herein a framework of focal vasomotor contractility being controlled by pharmacomechanical coupling and the generation of Ca waves via the sarcoplasmic reticulum. We argue the latter is sustained by receptor operated, transient receptor potential (TRP) channels through direct extracellular Ca influx or indirect Na influx, reversing the Na/Ca exchanger. We view this focal regulatory mechanism as complementary, but not redundant with, electromechanical coupling in the precision tuning of blood flow delivery.
动脉网络受刺激的整合输出控制，这些刺激决定了血流输送的“多少”（幅度）和“位置”（分布）。虽然幅度上的显著变化与全网络反应相关，但分布的改变通常源于张力的局部变化，其机制基础仍不清楚。我们在此提出一个框架，即局部血管运动收缩性受药物机械偶联和通过肌浆网产生钙波的控制。我们认为，后者通过受体操纵的瞬时受体电位（TRP）通道，通过细胞外钙的直接内流或间接的钠内流得以维持，从而逆转钠/钙交换体。我们认为这种局部调节机制在血流输送的精确调节中与机电偶联互补，但并非冗余。
