Invited review: effects of flow on vascular endothelial intracellular calcium signaling of rat aortas ex vivo.
To study the effects of flow on in situ endothelial intracellular calcium concentration ([Ca(2+)](i)) signaling, rat aortic rings were loaded with fura 2, mounted on a tissue flow chamber, and divided into control and flow-pretreated groups. The latter was perfused with buffer at a shear stress of 50 dyns/cm(2) for 1 h. Endothelial [Ca(2+)](i) responses to ACh or shear stresses were determined by ratio image analysis. Moreover, ACh-induced [Ca(2+)](i) elevation responses were measured in a calcium-free buffer, or in the presence of SKF-96365, to elucidate the role of calcium influx in the flow effects. Our results showed that 1) ACh increased endothelial [Ca(2+)](i) in a dose-dependent manner, and these responses were incremented by flow-pretreatment; 2) the differences in ACh-induced [Ca(2+)](i) elevation between control and flow-pretreated groups were abolished by SKF-96365 or by Ca(2+)-free buffer; and 3) in the presence of 10(-5) M ATP, shear stress induced dose-dependent [Ca(2+)](i) elevation responses that were not altered by flow-pretreatment. In conclusion, flow-pretreatment augments the ACh-induced endothelial calcium influx in rat aortas ex vivo.
Jen
C J
CJ
Department of Physiology, National Cheng-Kung University Medical College, Tainan, Taiwan 701, Republic of China.
Jhiang
S J
SJ
Chen
H I
HI
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001013:Aorta, Thoracic / Q000502:physiology*; D002118:Calcium / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology*; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology*; D007093:Imidazoles / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D011312:Pressure; D051381:Rats; D017207:Rats, Sprague-Dawley; D013314:Stress, Mechanical
D002121:Calcium Channel Blockers; D007093:Imidazoles; C063159:1-(2-(3-(4-methoxyphenyl)propoxy)-4-methoxyphenylethyl)-1H-imidazole; D000109:Acetylcholine; D002118:Calcium