The sarcoplasmic reticulum, Ca2+ trapping, and wave mechanisms in smooth muscle.
The sarcoplasmic reticulum (SR) and apposed regions of the sarcolemma passively trap Ca2+ entering the cell to limit the rise in cytoplasmic Ca2+ concentration without SR pump involvement. When "leaky," the SR facilitates Ca2+ entry to the cytoplasm. SR Ca2+ release via inositol 1,4,5-trisphosphate receptors (IP(3)Rs) propagates as calcium waves; IP(3)Rs alone account for wave propagation.
McCarron
John G
JG
Institute of Biomedical and Life Sciences, Neuroscience and Biomedical Systems, University of Glasgow, Glasgow G12 8QQ, Scotland, UK.
Bradley
Karen N
KN
MacMillan
Debbi
D
Chalmers
Susan
S
Muir
Thomas C
TC
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D009130:Muscle, Smooth / Q000502:physiology*; D012519:Sarcoplasmic Reticulum / Q000378:metabolism*
D002118:Calcium