Pacemaker Mechanisms Driving Pyeloureteric Peristalsis: Modulatory Role of Interstitial Cells

ATYPICAL or INTERSTITIAL, take your PIC

“…PDGFRα + /smMHC − ICs that expressed Ano1 and c‐Kit + /smMHC − ICs that displayed spontaneous Ca 2+ transients of variable frequencies. The molecular and pharmacological results presented agree well with previous reports of regional distribution and temporal properties of the Ca 2+ signals in ASMCs, TSMCs and two populations of ICs (Lang & Hashitani, 2019), as well as demonstrating major differences in PDGFRα + ICs and c‐Kit + ICs in expression of SK3 and Ano1 channels from PDGFRα + cells and ICC in the colon (Grainger et al . 2020).…”

“…ASMCs form a loosely packed ‘basket weave’ outer layer in single‐papilla kidneys or a continuous inner layer between the minor calyces of multi‐papilla kidneys (Dixon & Gosling, 1982; Klemm et al . 1999; Lang & Hashitani, 2019). Comparisons of TSMC and ASMC distributions in the various regions of the renal pelvis reveal that ASMC numbers decrease while TSMC numbers increase with distance from the papilla border (Klemm et al .…”

“…ASMCs develop spontaneous Ca 2+ transients primarily arising from the uptake and release of Ca 2+ from sarcoplasmic reticulum Ca 2+ stores that trigger spontaneous transient depolarisations (STDs) to electrically drive action potential firing in neighbouring TSMCs (Klemm et al . 1999; Lang & Hashitani, 2019). Using the α‐smooth muscle actin (αSMA)–enhanced yellow fluorescent protein (eYFP) reporter mouse strain, only one study has distinguished freshly dispersed single αSMA + ASMCs from intensely αSMA + TSMCs by their weaker fluorescence and by a difference in their ion channel expression (Iqbal et al .…”

“…Using the α‐smooth muscle actin (αSMA)–enhanced yellow fluorescent protein (eYFP) reporter mouse strain, only one study has distinguished freshly dispersed single αSMA + ASMCs from intensely αSMA + TSMCs by their weaker fluorescence and by a difference in their ion channel expression (Iqbal et al . 2012; Lang & Hashitani, 2019). These two αSMA + cells were accompanied by a population αSMA − interstitial cells (ICs) that displayed many of the K + and Cl − currents in common with both ASMCs and TSMCs.…”

“…More importantly, numerous electron micrographs have established that ASMCs little resemble ICs within the renal pelvis (Dixon & Gosling, 1982; Klemm et al . 1999; Lang & Hashitani, 2019). ASMCs express both smMHC and αSMA consistent with a contractile phenotype.…”