Spontaneous electrical and Ca²⁺ signals in typical and atypical smooth muscle cells and interstitial cell of Cajal‐like cells of mouse renal pelvis

Abstract

2+ transient discharge suggesting that they may well be acting as 'point sources' of excitation to the TSMC layer. We speculate that ASMCs act as the primary pacemaker in the renal pelvis while ICC-LCs play a supportive role, but can take over pacemaking in the absence of the proximal pacemaker drive.

Interstitial cells of Cajal generate spontaneous transient depolarizations in the rat gastric fundus

“…STDs had highly variable amplitude (1-30 mV) and frequency (20 -40/min). These properties were different from those of pacemaker potentials, which are generated rhythmically with the stable amplitude and frequency, recorded from ICC-MY of gastric antrum or small intestine (10,19), and rather similar to those of STDs in smooth muscle of the urethra (9) or renal pelvis (24). Figure 1 shows examples of unitary potentials and STDs recorded from the same preparation.…”

Identification of Interstitial Cajal-Like Cells in the Human Thoracic Duct

“…Interstitial Cajallike cells (ICLCs), or telocytes as they are also known, are morphologically distinct from smooth muscle cells (SMCs) and while they can be identified by expression of proteins specific to them (such as the receptor tyrosine kinase c-kit), ultrastructural assessment by transmission electron microscopy is the unequivocal method for identifying and distinguishing ICLCs from other interstitial cells, such as fibroblasts [Faussone-Pellegrini and Popescu, 2011]. Several spontaneously active smooth musclecontaining tissues expressing c-kit-positive ICLCs have been found in human [Metzger et al, 2004;Metzger et al, 2008;Ahmadi et al, 2010] and animals [Lang et al, 2007;Lavoie et al, 2007], but to date there is only a single report of lymphatic ICLCs from a study of sheep mesenteric lymphatics [McCloskey et al, 2002]. Given that human TD is known to be spontaneously contractile and the suggestion that ICLCs could contribute to this function in other smooth muscles, we proposed that ICLCs could be present in the wall of the human TD.…”

Diminished hERG K+ channel activity facilitates strong human labour contractions but is dysregulated in obese women

“…Many smooth muscle tissues display plateau-like electrical activity, which dictates the amplitude and duration of contraction [22][23][24][25] , and this includes the circular muscle layer of the mouse myometrium 24 . While the level of the plateau in many cases is close to that observed in human myometrium, À 25 to À 30 mV, a striking feature of the AP plateau in human myometrium is the rapidity of repolarization.…”