High impact information on DM-Nitrophen

• We have used the caged calcium compound DM-nitrophen to investigate the kinetics of calcium-dependent secretion in bovine chromaffin cells [1].
• Photolysis of a calcium cage, DM-nitrophen, accelerated the frequency of synaptic currents in muscle-contacted, but not novel neuron-contacted, B19 somata [2].
• By contrast, in trp photoreceptors, which lack one class of Ca2+ permeable light-sensitive channel, photolysis of DM-nitrophen induced a significant facilitation during the falling phase of the response, but during the rising phase photolysis significantly depressed the overall response [3].
• In order to test the hypothesis that Ca2+ is the excitatory messenger rapid concentration jumps of cytosolic Ca2+ were achieved in dissociated Drosophila photoreceptors by flash photolysis of the caged Ca2+ compounds DM-nitrophen and nitr-5 [3].
• In the second method, we overcome these problems by using calcium-loaded DM-nitrophen as a light-dependent calcium source to homogeneously and quantitatively release calcium in the cytosol [4].

Biological context of DM-Nitrophen

• The photolabile Ca2+ chelator DM-nitrophen was used to rapidly release Ca2+ into the extravesicular spaces throughout an oriented SR membrane multilayer and thereby synchronously in the vicinity of the high affinity binding sites of each enzyme molecule in the multilayer [5].
• 9. MEJP frequency and EJP amplitudes during DM-nitrophen photolysis were fitted to a 'non-linear summation model' in which photolytically released calcium sums with calcium entering during an action potential to evoke transmitter release with a calcium co-operativity of five [6].
• Millisecond studies of calcium-dependent exocytosis in pituitary melanotrophs: comparison of the photolabile calcium chelators nitrophenyl-EGTA and DM-nitrophen [7].
• Studies of the effects of RLC phosphorylation on the kinetics of force activation with the caged Ca2+, DM-nitrophen, showed a slight increase in the rates of force development with low statistical significance [8].

Anatomical context of DM-Nitrophen

• 1. Transmitter release at the squid giant synapse was stimulated by photolytic release of Ca2+ from the 'caged' Ca2+ compound DM-nitrophen (Kaplan & Ellis-Davies, 1988) inserted into presynaptic terminals [9].
• Intracellular photorelease of Ca2+ from "caged calcium" (DM-nitrophen) was used to investigate the Ca(2+)-activated currents in ventricular myocytes isolated from guinea pig hearts [10].
• Calcium released by photolysis of DM-nitrophen triggers transmitter release at the crayfish neuromuscular junction [6].
• 1. Changes in membrane capacitance evoked by the rapid photolysis of a caged Ca2+ compound, DM-nitrophen or nitrophenyl-EGTA, were investigated in undifferentiated PC12 cells [11].
• To determine the role of myosin regulatory light chain (RLC) in modulating contraction in skeletal muscle, we examined the rate of tension development in bundles of skinned skeletal muscle fibers as a function of the level of Ca(2+) activation after UV flash-induced release of Ca(2+) from the photosensitive Ca(2+) chelator DM-nitrophen [12].

Associations of DM-Nitrophen with other chemical compounds

• To study the kinetics of 5-HT reuptake in functional synapses, transmitter release was stimulated by flash photolysis of the Ca(2+)-caging DM-nitrophen [13].
• 3. The kinetics of activation and relaxation were examined in skinned multicellular preparations using the caged Ca2+ compound DM-nitrophen and caged Ca2+ chelator diazo-2, respectively [14].
• After flash photolysis of DM-Nitrophen (a caged Ca(2+) chelator), spermine accelerated the rate of tension development at low and intermediate but not high [Ca(2+)] [15].
• Measurement of intracellular Ca2+ concentration using Indo-1 during simultaneous flash photolysis to release Ca2+ from DM-nitrophen [16].

Gene context of DM-Nitrophen

• Flash photolysis of DM-nitrophen generates an extremely large [Ca2+] transient ("Ca2+ spike") at the start of each Ca2+ "step." The Ca2+ spike greatly increases the speed of activation of the ryanodine receptor channel ("supercharging") and could be responsible for apparent channel adaptation [17].

Analytical, diagnostic and therapeutic context of DM-Nitrophen

• The effect of several modifications to the reaction chemistry, the addition of the caged-magnesium dye DM-Nitrophen, the replacement of human DNA template with PCR product, and the coating of the microchannel surface with Teflon were all studied [18].
• 5. Iontophoresis of calcium-free DM-nitrophen into presynaptic terminals released transmitter upon photolysis, but only in a calcium-containing Ringer solution [6].
• Ultra-rapid freezing and electron microscopy were used to directly observe structural details of frog muscle fibers in rigor, in relaxation, and during force development initiated by laser photolysis of DM-nitrophen (a caged Ca2+) [19].
• Intracellular photorelease of Ca2+ from caged Ca2+ (DM-nitrophen or nitr5) and the patch-clamp technique in the whole-cell configuration were used to investigate Ca(2+)-activated currents in inner hair cells (IHCs) of the mammalian cochlea [20].
• Ca2+ binding to sarcoplasmic reticulum Ca(2+)-ATPase was investigated by Fourier transform infrared (FTIR) spectroscopy using the photolytic release of Ca2+ from the photolabile Ca2+ chelator 1-(2-nitro-4,5-dimethoxy)-N,N,N',N',- tetrakis[(oxycarbonyl)]methyl-1,2-ethandiamine (DM-nitrophen) [21].

References