Facilitation of L-type Ca2+ currents by fluid flow in rabbit cerebral artery myocytes.
Blood vessels are receptive to hemodynamic forces, such as blood pressure and flow, which result in myogenic responses. The present study aimed to investigate the effect of mechanical stresses on L-type voltage-dependent Ca(2+) channels in rabbit cerebral artery myocytes. Cell swelling induced by the exposure to a 16% hypotonic solution increased peak values of whole-cell Ba(2+) currents (IBa). Similarly, an elevation of bath perfusion rate increased peak values of IBa. However, the response was reduced by the continued fluid flow stimulation and the current amplitude almost returned to the baseline. This reduction of the current was abolished by pretreatment with thapsigargin, implying the contribution of Ca(2+) release from the sarcoplasmic reticulum to the response. These results suggest that L-type Ca(2+) currents are facilitated not only by cell swelling but also by fluid flow in cerebral artery myocytes.
Amano
Satoshi
S
Department of Cellular and Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Shizuoka City, Shizuoka 422-8526, Japan.
Ishikawa
Tomohisa
T
Nakayama
Koichi
K
D000818:Animals; D020746:Calcium Channels, L-Type / Q000187:drug effects / Q000502:physiology*; D002536:Cerebral Arteries / Q000166:cytology; D045604:Extracellular Fluid / Q000378:metabolism; D005260:Female; D007038:Hypotonic Solutions / Q000494:pharmacology; D007700:Kinetics; D008297:Male; D040542:Mechanotransduction, Cellular / Q000187:drug effects / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D018408:Patch-Clamp Techniques; D010477:Perfusion; D011817:Rabbits; D013314:Stress, Mechanical; D019284:Thapsigargin / Q000494:pharmacology
D020746:Calcium Channels, L-Type; D007038:Hypotonic Solutions; D019284:Thapsigargin