Disease relevance of [2-[2-[2-(bis(carboxymethyl)amino)-5-methyl-phenoxy]ethoxy]-4-[3,6-bis(dimethylamino)xanthen-9-ylidene]-1-cyclohexa-2,5-dienylidene]-bis(carboxymethyl)ammonium

• Using Rhod-2-AM loaded cardiomyocytes, we found that UTP reduced mitochondrial calcium levels following hypoxia [1].
• In another series of experiments, rhod-2 was injected directly into 12 pyramidal cell-like neurons in layer II/III through patch pipettes, and changes in Ca2+ concentration in apical dendritic areas during tetanus were measured simultaneously with recordings of excitatory postsynaptic potentials (EPSPs) evoked by test stimulation of layer IV [2].
• Here we compare [Ca2+]i-changes induced by trimethyltin chloride in neuroblastoma SY5Y and HeLa S3 cells using calcium-sensitive dyes (fluo-4/AM (fluo-4) and rhod-2/AM (rhod-2)) and laser scanning microscopy (LSM) [3].

High impact information on [2-[2-[2-(bis(carboxymethyl)amino)-5-methyl-phenoxy]ethoxy]-4-[3,6-bis(dimethylamino)xanthen-9-ylidene]-1-cyclohexa-2,5-dienylidene]-bis(carboxymethyl)ammonium

• We imaged the activity of astrocytes labeled with the calcium (Ca(2+))-sensitive indicator rhod-2 in somatosensory cortex of adult mice [4].
• In addition, we find that rhod-2 labels mitochondria in T cells, and it reports changes in Ca2+ levels that are consistent with its localization in the TG-insensitive store [5].
• We used the action potential voltage-clamp technique on ventricular myocytes loaded with indo 1 or rhod 2, both Ca2+ indicators, to study the relation between action potential duration, ICa-L, and cell shortening (inotropic effect) [6].
• Measurement of [Ca2+]i by use of rhod 2 showed that changes in the rate of rise of the [Ca2+]i transient (which in rat ventricle is due to the rate of Ca2+ release from the sarcoplasmic reticulum) were closely correlated with changes in the magnitude and the time course of ICa-L.(ABSTRACT TRUNCATED AT 400 WORDS)[6]
• Successful transfection was verified in single cells by detection of GFP, and intracellular Ca2+ ([Ca]i) changes were simultaneously monitored with rhod-2 [7].

Biological context of [2-[2-[2-(bis(carboxymethyl)amino)-5-methyl-phenoxy]ethoxy]-4-[3,6-bis(dimethylamino)xanthen-9-ylidene]-1-cyclohexa-2,5-dienylidene]-bis(carboxymethyl)ammonium

• 2. Following selective loading of the presynaptic terminals with the fluorescent Ca2+ indicator rhod-2 AM, transient increases in the presynaptic Ca2+ concentration (pre[Ca2+]t) and field excitatory postsynaptic potentials (EPSPs) evoked by electrical stimulation of the SCC pathway were recorded simultaneously [8].
• Perfused rabbit hearts were stained with RH327 and Rhod-2/AM to simultaneously map membrane potential (V(m)) and Ca2+i with two photodiode arrays [9].
• 1. The mechanisms underlying electro-mechanical alternans caused by faster heart rates were investigated in perfused guinea-pig hearts stained with RH237 and Rhod-2 AM to simultaneously map optical action potentials (APs) and intracellular free Ca2+ (Ca2+i) [10].
• Fura-2-induced deceleration of [Ca(2+)](i) decline resulted from increased cytosolic Ca(2+) buffering, because the kinetics of rhod-2 decay resembled those obtained with fura-2 after incorporation of the Ca(2+) chelator BAPTA [11].
• Confocal microscopy demonstrated that sperm Ca2+ content differed between low and high sperm-mobility phenotypes when sperm were stained with rhod-2 AM, a Ca2+ -specific dye [12].

Anatomical context of [2-[2-[2-(bis(carboxymethyl)amino)-5-methyl-phenoxy]ethoxy]-4-[3,6-bis(dimethylamino)xanthen-9-ylidene]-1-cyclohexa-2,5-dienylidene]-bis(carboxymethyl)ammonium

• Applying imaging and single-cell photometric methods, we find that the probe rhod-2 selectively localizes to mitochondria and uses its responses to quantify mitochondrial free [Ca2+] (Cam) [13].
• We used SEER (shifted excitation and emission ratioing of fluorescence) of SR-trapped mag-indo-1 and confocal imaging of fluorescence of cytosolic rhod-2 to image Ca2+ sparks while reversibly changing and measuring [Ca2+] in the SR ([Ca2+]SR) of membrane-permeabilized frog skeletal muscle cells [14].
• 1. The Ca(2+)-sensitive fluorescent indicator rhod-2 was used to monitor mitochondrial Ca2+ concentration ([Ca2+]m) in gastric smooth muscle cells from Bufo marinus [15].
• IL-6 induced an increase in inner mitochondrial membrane polarisation and increased mitochondrial Ca2+ loading (rhod-2 fluorescence) at baseline, but prevented the reperfusion-induced changes in mitochondrial function [16].
• 1. The Ca2+-sensitive fluorescent indicator rhod-2 was used to measure mitochondrial [Ca2+] ([Ca2+]m) in single smooth muscle cells from the rat pulmonary artery, while simultaneously monitoring cytosolic [Ca2+] ([Ca2+]i) with fura-2 [17].

Associations of [2-[2-[2-(bis(carboxymethyl)amino)-5-methyl-phenoxy]ethoxy]-4-[3,6-bis(dimethylamino)xanthen-9-ylidene]-1-cyclohexa-2,5-dienylidene]-bis(carboxymethyl)ammonium with other chemical compounds

• Using Calcium Green-1 and rhod-2 as optical measures of cytoplasmic and mitochondrial free Ca(2+), we show that mitochondria sequester Ca(2+) and tune the frequency of [Ca(2+)](cyt) oscillations in rat gonadotropes [18].
• In parallel, monitoring of mitochondrial Ca(2+) during stress, via the specific indicator rhod-2, revealed a significant attenuation of Ca(2+) accumulation in mitochondria overexpressing K(+) channels [19].
• Luminometry of healthy fibroblasts expressing either aequorin or luciferase in the mitochondrial matrix showed that rhod-2 dose dependently decreased the Bk-induced increase in [Ca2+]M and [ATP]M by maximally 80 and 90%, respectively [20].
• The effects of uncouplers were investigated in perfused mouse hearts labeled with rhod-2/AM or 4-[beta-[2-(di-n-butylamino)-6-naphthyl]vinyl]pyridinium (di-4-ANEPPS) to map [Ca(2+)](i) transients (emission wavelength = 585 +/- 20 nm) and action potentials (APs) (emission wavelength > 610 nm; excitation wavelength = 530 +/- 20 nm) [21].
• Exposing cells to ouabain (1 mM) evoked mitochondrial Ca2+ overload and increased the intensity of rhod-2 fluorescence to 180+/-15% of baseline ( p<0.001) [22].

Gene context of [2-[2-[2-(bis(carboxymethyl)amino)-5-methyl-phenoxy]ethoxy]-4-[3,6-bis(dimethylamino)xanthen-9-ylidene]-1-cyclohexa-2,5-dienylidene]-bis(carboxymethyl)ammonium

• Individual mitochondria of rhod-2 loaded acinar cells showed heterogeneous matrix Ca(2+) concentration increases in response to oscillatory and maximal levels of cholecystokinin octapeptide [23].
• Moreover, CCK did not affect NMDA-induced Ca2+ influx measured with rhod-2, a fluorescent Ca2+ indicator [24].
• Staining of calcium stores with rhod-2 showed a TMT-induced [Ca2+]i-decrease in the stores followed by an increase of the calcium concentration in the nuclei of the two cell lines tested [3].

Analytical, diagnostic and therapeutic context of [2-[2-[2-(bis(carboxymethyl)amino)-5-methyl-phenoxy]ethoxy]-4-[3,6-bis(dimethylamino)xanthen-9-ylidene]-1-cyclohexa-2,5-dienylidene]-bis(carboxymethyl)ammonium

• Mitochondrial [Ca2+] (measured with rhod-2 and confocal microscopy) increased during repeated tetanic stimulation in CK-/- but not in wild-type FDB fibres [25].
• (3) Isolated rabbit hearts were subjected to I/R, and [Ca(2+)](i) was recorded by surface rhod-2 spectrofluorometry [26].
• 8. Changes in [Ca(2+)](i) in an acidic medium were determined in hippocampal slices by microfluorometry using rhod-2 acetoxymethyl ester as a Ca(2+) marker, and the effects of dexamethasone (240 microg/l) was evaluated [27].
• In 16 slices loaded with rhod-2 through the perfusion medium, tetanic stimulation of theta-burst type was applied to layer IV of the cortex and changes in Ca2+ concentration were analyzed in layer II/III from which field potentials to test stimulation of layer IV were recorded simultaneously [2].

References