Calcium Signalling in Pericytes

Abstract

Recent advances in pericyte research have contributed to our understanding of the physiology and pathophysiology of microvessels. The microvasculature consists of arteriolar and venular networks located upstream and downstream of the capillaries. Arterioles are surrounded by a monolayer of spindle-shaped myocytes, while terminal branches of precapillary arterioles, capillaries and all sections of postcapillary venules are encircled by a monolayer of morphologically diverse pericytes. There are physiological differences in the response of pericytes and myocytes to vasoactive molecules, suggesting that these two vascular cell types could have different functional roles in the regulation of local blood flow. The contractile activity of pericytes and myocytes is controlled by changes of cytosolic free Ca²⁺ concentration. In this short review, we summarize our results and those of other authors on the contractility of pericytes and their Ca²⁺ signalling. We describe results regarding sources of Ca²⁺ and mechanisms of Ca²⁺ release and Ca²⁺ entry in control of the spatiotemporal characteristics of the Ca²⁺ signals in pericytes.

Role of capillary pericytes in the integration of spontaneous Ca2+ transients in the suburothelial microvasculature in situ of the mouse bladder

“…Capillary pericytes are often non‐contractile and do not express α‐smooth muscle actin (α‐SMA) (Borysova et al . ; Burdyga & Borysova, ; Hill et al . ).…”

“…Arterioles or venules are surrounded by contractile smooth muscle cells (SMCs), whereas capillaries and pre-and post-capillary microvessels are covered by morphologically distinct pericytes. Capillary pericytes are often non-contractile and do not express α-smooth muscle actin (α-SMA) (Borysova et al 2013;Burdyga & Borysova, 2014;Hill et al 2015). Nevertheless, capillary pericytes in several vascular beds of the CNS play an active role in regulating capillary diameter and blood flow (Peppiatt et al 2006;Femández-Klett et al 2010;Hall et al 2014).…”

Pacemaker role of pericytes in generating synchronized spontaneous Ca2+ transients in the myenteric microvasculature of the guinea-pig gastric antrum

“…However, it was reported that L-type VDCCs have a minimal role in establishing the basal Ca 2+ concentration of capillary pericytes, while L-type VDCCs in mural cells in the proximal retinal microvasculature exhibit significant basal activity [29]. Thus, in terms of the involvement of L-type VDCCs, the properties of Ca 2+ transients in the microvasculature seem to vary amongst vascular beds or may exhibit regional differences even within a microvascular network (see also [30]). Importantly, we found that the near synchronous mural cell Ca 2+ transients in the myenteric microvasculature were abolished by blockers of T-type VDCCs used at concentrations comparable to those used to completely block Ca v 3.1 T-type VDCCs [20,31].…”

Cannabinoids Regulate the Diameter of Pericyte-Containing Retinal Capillaries in Rats

“…It is well established that pericyte-containing capillaries are important functional units involved in regulating tissue blood supply [1]. When the sensory input increases blood flow in vivo , capillaries dilate before the arterioles [2] and account for up to 84% of the increase in blood flow.…”