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Confocal microscopy of fluo-4 fluorescence in pressurized rat mesenteric small arteries subjected to low-frequency electrical field stimulation revealed Ca2+ transients in perivascular nerves and novel, spatially localized Ca2+ transients in adjacent smooth muscle cells. These muscle Ca2+ transients occur with a very brief latency to the stimulus pulse(More)
We used post-transcriptional gene silencing (with small interfering RNA) to examine specifically the roles of Type 1 inositol tris-phosphate receptors (InsP(3)R1) and transient receptor potential channel 6 (TRPC6) in Ca(2+) oscillations induced by arginine vasopressin (AVP), a typical G-protein coupled receptor agonist. Ca(2+) oscillations were observed in(More)
Contraction of small arteries is regulated by the sympathetic nervous system, but the Ca2+ transients during neurally stimulated contraction of intact small arteries have not yet been recorded. We loaded rat mesenteric small arteries with the fluorescent Ca2+ indicator fluo-4 and mounted them in a myograph that permitted simultaneous (i) high-speed confocal(More)
The effects of caffeine on tension, membrane potential, membrane currents, and intracellular [Ca2+], measured as the light emitted by the Ca2+-activated photoprotein aequorin, were studied in canine cardiac Purkinje fibers. An initial, transient, positive inotropic effect of caffeine was accompanied by a transient increase in the second component of the(More)
The sympathetic nervous system (SNS) plays an essential role in the control of total peripheral vascular resistance by controlling the contraction of small arteries. The SNS also exerts long-term trophic influences in health and disease; SNS hyperactivity accompanies most forms of human essential hypertension, obesity and heart failure. At their junctions(More)
BACKGROUND AND PURPOSE Determining the role of vascular receptors in vivo is difficult and not readily accomplished by systemic application of antagonists or genetic manipulations. Here we used intravital microscopy to measure the contributions of sympathetic receptors, particularly α1-adrenoceptor subtypes, to contractile activation of femoral artery in(More)
Regulation of cochlear blood flow is critical for hearing due to its exquisite sensitivity to ischemia and oxidative stress. Many forms of hearing loss such as sensorineural hearing loss and presbyacusis may involve or be aggravated by blood flow disorders. Animal experiments and clinical outcomes further suggest that there is a gender preference in hearing(More)
The sympathetic nervous system plays an essential role in the control of total peripheral vascular resistance and blood flow, by controlling the contraction of small arteries. Perivascular sympathetic nerves release ATP, norepinephrine (NE) and neuropeptide Y. This review summarizes our knowledge of the intracellular Ca2+ signals that are activated by ATP(More)
Calcium sparks are brief, highly localized elevations of [Ca 2 ϩ ], which arise spontaneously or can be evoked by depolarization in many types of muscle cells. The Ca 2 ϩ is released into the cytoplasm from intracellular stores (the SR) through the SR Ca 2 ϩ release channels (the RYR). Since their discovery (in cardiac muscle; Cheng et al., 1993), Ca 2 ϩ(More)
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