title: Different effect of Rho kinase inhibition on calcium signaling in rat isolated large and small arteries.
abstract: In addition to its role in the regulation of artery contraction, Rho kinase (ROCK) was reported to be involved in the cytosolic calcium response to vasoconstrictor agonists in rat aorta and superior mesenteric artery (SMA). However, it remains to be determined whether ROCK also contributes to calcium signaling in resistance arteries, which play a major role in blood pressure regulation. The investigation of the effect of ROCK inhibition on the calcium and contractile responses of rat resistance mesenteric artery (RMA), in comparison with aorta and SMA, indicated that the calcium response to noradrenaline was inhibited by the ROCK inhibitor Y-27632 in aorta and SMA but not in RMA. The effect of Y-27632 on the calcium signal was unaffected by cytochalasin-D. ROCK activation in noradrenaline-stimulated arteries was confirmed by the inhibition of myosin light chain phosphorylation by Y-27632. Moreover, noradrenaline-induced calcium signaling was similarly inhibited by nimodipine in aorta, SMA and RMA, but nimodipine sensitivity of the contraction increased from the aorta to the RMA, suggesting that the contraction was controlled by different sources of calcium. In pressurized RMA, Y-27632 and H-1152 depressed pressure-induced calcium responses and abolished myogenic contraction. These results stress the important differences in calcium signaling between conductance and resistance arteries.
authors.affiliation: Department of Cellular Physiology, Institute of Neuroscience, Université Catholique de Louvain, Brussels, Belgium.
authors.forename: Anneloes
authors.initials: A
authors.lastname: Martinsen
authors.forename: Xavier
authors.initials: X
authors.lastname: Yerna
authors.forename: Géraldine
authors.initials: G
authors.lastname: Rath
authors.forename: Elvira Leon
authors.initials: EL
authors.lastname: Gomez
authors.forename: Chantal
authors.initials: C
authors.lastname: Dessy
authors.forename: Nicole
authors.initials: N
authors.lastname: Morel
mesh_terms: D000577:Amides / Q000494:pharmacology*; D000818:Animals; D001011:Aorta / Q000187:drug effects* / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects*; D017538:Mesenteric Artery, Superior / Q000187:drug effects; D009638:Norepinephrine / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D014661:Vasoconstriction / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D054460:rho-Associated Kinases / Q000037:antagonists & inhibitors*
chemical_list: D000577:Amides; D004791:Enzyme Inhibitors; D011725:Pyridines; D014662:Vasoconstrictor Agents; C108830:Y 27632; D054460:rho-Associated Kinases; D009638:Norepinephrine