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Smooth muscle and endothelial cells in the arterial wall are exposed to mechanical stress. Indeed blood flow induces intraluminal pressure variations and shear stress. An increase in pressure may induce a vessel contraction, a phenomenon known as the myogenic response. Many muscular vessels present vasomotion, i.e., rhythmic diameter oscillations caused by(More)
To evaluate the regulation of connexin expression by fluid pressure, we have studied the effects of elevated transmural urine pressure on Connexin43 (Cx43) and Cx26. We chose to focus on these two proteins out of the five connexins (Cx26, 43, 40, 37, and 45) which we found by RT-PCR to be expressed in the rat bladder, since in situ hybridization and(More)
We investigated heterocellular communication in rat mesenteric arterial strips at the cellular level using confocal microscopy. To visualize Ca(2+) changes in different cell populations, smooth muscle cells (SMCs) were loaded with Fluo-4 and endothelial cells (ECs) with Fura red. SMC contraction was stimulated using high K(+) solution and Phenylephrine.(More)
BACKGROUND/AIMS Smooth muscle tone is controlled by Ca(2+) signaling in the endothelial layer. Mouse endothelial cells are interconnected by gap junctions made of Connexin40 (Cx40) and Cx37, which allow the exchange of signaling molecules to coordinate their activity. Here, we investigated the role of Cx40 in the endothelial Ca(2+) signaling of the mouse(More)
Investigating the recruitment and synchronization of smooth muscle cells (SMCs) is the key to understanding the physical mechanisms leading to contraction and spontaneous diameter oscillations of arteries, called vasomotion. We improved a method that allows the correlation of calcium oscillations (flashing) of individual SMCs with mean calcium variations(More)
In vitro, different techniques are used to study the smooth muscle cells' calcium dynamics and contraction/relaxation mechanisms on arteries. Most experimental studies use either an isometric or an isobaric setup. However, in vivo, a blood vessel is neither isobaric nor isometric nor isotonic, as it is continuously submitted to intraluminal pressure(More)
  • J L Bény
  • 1990
Thimerosal activates the production of endothelium-derived relaxing factor (EDRF). I examined whether thimerosal also causes the release of an endothelium-dependent hyperpolarizing factor (EDHF). Thimerosal caused an endothelium-dependent hyperpolarization of smooth muscle. This effect is unlikely to be caused by the property of thimerosal to inhibit the(More)
Using strips of the left descending branch of the pig coronary artery in vitro, we show that smooth muscle cells are hyperpolarized by isoproterenol, a beta-agonist, independently of the presence or absence of intact endothelium. This hyperpolarization is transmitted to the lining endothelial cells in intact coronary strips. On the contrary, the cultured(More)
We tested for dye coupling between arteriolar smooth muscle cells (SMC) and endothelial cells (EC) and investigated the correspondence of vasomotor activity with changes in the membrane potential (Vm) of EC and SMC during blood flow control. Female golden hamsters (n = 8, 90-170 g) were anesthetized (pentobarbital sodium, 60 mg/kg ip). A cheek pouch was(More)
Many experimental studies have shown that arterial smooth muscle cells respond with cytosolic calcium rises to vasoconstrictor stimulation. A low vasoconstrictor concentration gives rise to asynchronous spikes in the calcium concentration in a few cells (asynchronous flashing). With a greater vasoconstrictor concentration, the number of smooth muscle cells(More)