Methyl-beta-cyclodextrin prevents Ca2+-induced Ca2+ release in smooth muscle cells of mouse urinary bladder.
We examined the effects of methyl-beta-cyclodextrin (MbetaCD) on Ca(2+)-induced Ca(2+) release (CICR) in smooth muscle cells (SMCs) of mouse urinary bladder (UB). Short depolarization of UBSMCs under voltage-clamp elicited several local Ca(2+) transients (Ca(2+) hot spots) via CICR within 20 ms in discrete sub-sarcolemmal areas. Then, the Ca(2+) wave spread to whole areas. The pretreatment with 10 mM MbetaCD significantly attenuated Ca(2+) hot spots in UBSMCs and reduced contraction by single direct electrical pulse stimulation in UBSM strips. MbetaCD may prevent CICR by attenuating the coupling between voltage-dependent Ca(2+) channels and ryanodine receptors in Ca(2+) hot spot areas.
Hotta
Shingo
S
Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Japan.
Yamamura
Hisao
H
Ohya
Susumu
S
Imaizumi
Yuji
Y
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009119:Muscle Contraction / Q000187:drug effects; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000378:metabolism*; D019837:Ryanodine Receptor Calcium Release Channel / Q000502:physiology; D001743:Urinary Bladder / Q000187:drug effects / Q000378:metabolism*; D047392:beta-Cyclodextrins / Q000494:pharmacology*
D015220:Calcium Channels; D019837:Ryanodine Receptor Calcium Release Channel; D047392:beta-Cyclodextrins; C108732:methyl-beta-cyclodextrin; D002118:Calcium