Using microspectrofluorimetry and the calcium-sensitive dye fura-2, we examined the effect of excitatory amino acids on [Ca2+]i in single striatal neurons in vitro. N-methyl-D-aspartic acid (NMDA) produced rapid increases in [Ca2+]i. These were blocked by DL-2-amino-5-phosphonovaleric acid (AP5), by Mg2+, by phencyclidine, and by MK801. The block produced by Mg2+ and MK801 could be relieved by ...

Norepinephrine (NE) and glutamate (Glu) initiate intracellular calcium ([Ca2+]i) transients, oscillations, and intracellular [Ca2+]i waves in cultured astrocytes. To further elucidate the significance of NE- and Glu-evoked astrocytic [Ca2+]i signaling to neuron-astrocyte communication in the mature CNS, [Ca2+]i of astrocyte networks within hippocampal slices (P21-42) was measured during bath ap...

Changes in the concentration of free cytosolic Ca2+ [( Ca2+]i), membrane potential, and immunoreactive insulin release were measured in suspensions of RINm5F cells. [Ca2+]i was monitored with the intracellularly trapped fluorescent Ca2+ indicator quin 2. Changes in membrane potential were assessed with the fluorescent probe bisoxonol. The effects of depolarizing K+ concentrations and of the Ca2...

Intracellular free calcium concentration [( Ca2+]i) was measured with the fluorescent Ca2+ indicator Fura 2 within individual human neutrophils during the phagocytosis of several types of particles, including serum-treated zymosan (STZ), immunoglobulin G (IgG)-coated zymosan (IGZ), C3b-coated zymosan (C3Z), nontreated zymosan (Z), and serum-treated similarly sized latex particles (STL). STZ was...

Altered release of endothelium-derived relaxing factor/nitric oxide (EDRF/NO) has been proposed as a final common pathway underlying the abnormal vasodilator responses to gram-negative lipopolysaccharide (endotoxin). However, mechanisms responsible for lipopolysaccharide-induced changes in EDRF/NO release from endothelial cells have not been clarified. We evaluated direct effects of Escherichia...

Anderson, S. E., H. Liu, H. S. Ho, E. J. Lewis, and P. M. Cala. Age-related differences in Na -dependent Ca2 accumulation in rabbit hearts exposed to hypoxia and acidification. Am J Physiol Cell Physiol 284: C1123–C1132, 2003. First published January 8, 2002; 10.1152/ajpcell.00148. 2002.—In this study, we test the hypothesis that in newborn hearts (as in adults) hypoxia and acidification stimul...

Excitation-contraction coupling in cardiac myocytes occurs by Ca2+-induced Ca2+ release, where L-type Ca2+ current evokes a larger sarcoplasmic reticulum (SR) Ca2+ release. The Ca2+-induced Ca2+ release amplification factor or gain (SR Ca2+ release/I(Ca)) is usually assessed by the V(m) dependence of current and Ca2+ transients. Gain rises at negative V(m), as does single channel I(Ca) (i(Ca)),...

Second messenger signaling between endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) is poorly understood, but intracellular Ca2+ concentrations ([Ca2+]i) in the 2 cells are coordinated, possibly through gap junctions at the myoendothelial junction. To study heterocellular calcium signaling, we used a vascular cell coculture model composed of monolayers of ECs and VSMCs. Stimulat...

Stimulation of beta-adrenergic receptors on LRM55 astroglial cells results in cAMP-dependent release of taurine. We have previously demonstrated that extracellular Ca2+ is not required for either spontaneous or receptor-mediated taurine release (Martin et al., 1988b). In the present series of experiments we investigated the relationship between changes in intracellular free Ca2+ ([Ca2+]i) and t...

The affects of volatile anesthetics on mobilization of intracellular Ca2+ was monitored in primary cultures of rat hepatocytes using the fluorescent Ca2+ probe Fura-2. The use of Fura-2 was limited by several factors which complicated the quantitative analysis of the results, such as: (i) a high rate of dye leakage; (ii) changes in the redox state of the hepatocytes which interfered with the fl...