Effect of LED photobiomodulation on fluorescent light induced changes in cellular ATPases and Cytochrome c oxidase activity in Wistar rat.

BACKGROUND: Fluorescent light exposure at night alters cellular enzyme activities resulting in health defects. Studies have demonstrated that light emitting diode photobiomodulation enhances cellular enzyme activities. OBJECTIVE: The objectives of this study are to evaluate the effects of fluorescent light induced changes in cellular enzymes and to assess the protective role of pre exposure to 670 nm LED in rat model. METHODS: Male Wistar albino rats were divided into 10 groups of 6 animals each based on duration of exposure (1, 15, and 30 days) and exposure regimen (cage control, exposure to fluorescent light [1800 lx], LED preexposure followed by fluorescent light exposure and only LED exposure). Na+-K+ ATPase, Ca2+ ATPase, and cytochrome c oxidase of the brain, heart, kidney, liver, and skeletal muscle were assayed. RESULTS: Animals of the fluorescent light exposure group showed a significant reduction in Na+-K+ ATPase and Ca2+ ATPase activities in 1 and 15 days and their increase in animals of 30-day group in most of the regions studied. Cytochrome c oxidase showed increase in their level at all the time points assessed in most of the tissues. LED light preexposure showed a significant enhancement in the degree of increase in the enzyme activities in almost all the tissues and at all the time points assessed. CONCLUSIONS: This study demonstrates the protective effect of 670 nm LED pre exposure on cellular enzymes against fluorescent light induced change.

Calmodulin and the target size of the (Ca2+ + Mg2+)-ATPase of human red-cell ghosts.

An average target size of 251 kDa has been obtained for the (Ca2+ + Mg2+)-ATPase of calmodulin-depleted erythrocyte ghosts by radiation inactivation with 16 MeV electrons. This is close to twice the size of the purified calcium-pump polypeptide. When calmodulin was included during the ATPase assay, a component of about 1 MDa appeared in addition to the activated dimer.

Target sizes of human erythrocyte membrane Ca2+-ATPase and Mg2+-ATPase activities in the presence and absence of calmodulin.

We have investigated the subunit structure of Ca2+-transport ATPase in human erythrocyte membranes using radiation inactivation analysis. All inactivation data were linear on a semilog plot down to at least 20% of the control activity. We found a target size for the calmodulin-dependent Ca2+-ATPase activity of 331 kDa, consistent with the presence of this enzyme as a dimer in calmodulin-depleted ghosts. Membranes which had been saturated with calmodulin before irradiation yield a a similar size of 317 kDa, implying that activation of Ca2+-transport ATPase by calmodulin does not involve significant change in oligomeric structure. Basal (calmodulin-independent) Ca2+-ATPase activity corresponded to a size of 290 kDa, suggesting that this activity resides in the same, or similar-sized, complex as the calmodulin-dependent activity. Mg2+-ATPase activity, however, was found to reside in a smaller complex of 224 kDa, which proved to be statistically distinct from the target size of Ca2+-ATPase activity. It would appear that Mg2+-ATPase is a distinct entity whose function is likely unrelated to the Ca2+-transport ATPase.

Radiation inactivation analysis of sarcoplasmic reticulum Ca-ATPase in membrane-bound form and in detergent-solubilized monomeric states.

The sarcoplasmic reticulum Ca-ATPase was subjected to target size analysis by radiation inactivation in various buffer conditions and after solubilization in monomeric form in non-ionic detergent and in SDS. The target size was also determined for Ca-ATPase in bidimensional crystals formed in the presence of decavanadate or lanthanide. The standardization obtained with defined monomers of Ca-ATPase shows that the target size of Ca-ATPase in the functional membrane-bound state may be ascribed to a single peptide chain, possibly with surrounding lipid. Further analysis of the radiation inactivation sizes of various partial reactions of the pump cycle, including phosphorylation and Ca2+ occlusion, indicated much smaller values than the target size pertaining to decomposition of the whole peptide chain. This is consistent with the existence of separate functional domains within a single peptide chain.

[Protein-protein interactions in membranes: concepts and the example of calcium ATPase from the sarcoplasmic reticulum]. / Les interactions protéine-protéine dans les membranes: quelques concepts et l'exemple de l'ATPase calcique du reticulum sarcoplasmique.

The organization of polypeptide chains in the membrane has attracted widespread interest. This is particularly true for transport proteins: indeed, the existence of a quaternary structure may obviously have important implications for the mechanism of solute transport through the membrane. The problem arises from the fact that it is extremely difficult to demonstrate unambiguously that a protein is truly oligomeric in the membrane. In this paper various techniques are considered, either direct methods of investigation such as X-ray or neutron scattering, ESR, and radiation inactivation, or indirect methods (primarily the solubilization of the protein by non-denaturing detergents). In very few cases the existence of a 'structural' oligomer has been demonstrated. However, the question remains whether the oligomer also has a functional role, i.e., is it directly necessary for example to form a hydrophilic pathway for an ion, or indirectly to stabilize the enzyme structure or to allow a control to take place at a certain defined step of the transport cycle?.

Changes in the distribution of lens calcium during development of x-ray cataract.

The present study was designed to examine the possible role of calcium in the opacification of x-ray-induced cataract in rabbit. The results demonstrate that the concentration of calcium in x-rayed lenses, just prior to lens hydration (7.5 weeks postirradiation), was twice that present in contralateral control lenses. At this stage of immature cataract, the lens nucleus remained transparent and maintained a normal level of calcium, but the lens cortex, containing regions of subcapsular opacification, accumulated a level of calcium that was twice that of the control. In the completely opaque mature cataract, (8-9 weeks postx-ray), both the cortex and nucleus had gained significant amounts of calcium. As the concentration of total calcium increased in the immature x-ray cataract, the amount of the cation bound to membranes and insoluble proteins of the cytosol also increased comparably. However, the relative proportion of calcium in the various fractions remained unaltered in the immature cataract; in both control lenses and immature cataracts, 20% of the total calcium remained in the membrane pellet and 70% was located in the soluble protein fraction. Only in the mature stage of cataract was a shift in the distribution of calcium apparent, as the proportion of calcium in the soluble protein fraction increased to 90%. Although only 7% of the total calcium in a mature cataract was bound to membrane, the amount represented a fivefold increase over the control. The results of this study demonstrate that an elevation in lens calcium accompanies the opacification process in x-ray cataract. The work also suggests that changes in calcium levels are not likely to result from inactivation of Ca-ATPase.

Irradiation with ultraviolet light in the presence of vanadate increases Ca2+ permeability of the sarcoplasmic reticulum membrane via Ca(2+)-ATPase.

The sarcoplasmic reticulum (SR) of rabbit skeletal muscle was irradiated with ultraviolet light (UV) in the presence of vanadate plus 2 mM EGTA, 10 mM MgCl2, 20% DMSO, and 50 mM PIPES (pH 6.5) at room temperature. In the presence of 100 microM vanadate, the Ca(2+)-uptake activity of SR rapidly decreased and was almost lost in 20 min. The activity was inhibited as a function of vanadate concentration with an apparent Ki of about 20 microM. On the other hand, Ca(2+)-dependent ATP hydrolytic activity as well as phosphoenzyme (EP) formation activity decreased very slowly, and more than 50% of these activities remained 20 min after initiation of the vanadate-UV treatment. Half inhibition of these activities required about 100 microM vanadate. The loss of the relationship between Ca(2+)-uptake and ATPase reaction was found to be mainly caused by an increase in the Ca2+ permeability of the SR membrane, which was raised by increasing the vanadate concentration or UV irradiation time in a manner similar to that observed for the Ca2+ uptake. No rise in Ca2+ permeability occurred in liposomes reconstituted from SR lipid when they were irradiated with UV in the presence of 100 microM vanadate. When the vanadate-UV-treated SR was allowed to react with fluoral-P (4-amino-3-penten-2-one), an indicator of aldehyde, and the membrane proteins were separated by HPLC in the presence of SDS, the fluorescent probe was found to be closely associated with the Ca(2+)-ATPase fraction.(ABSTRACT TRUNCATED AT 250 WORDS)

On the use of the phase memory time T2 for the quantitative characterization of the rotational motions of proteins in lipid bilayer systems.

Numerical simulations of the echo responses from a nitroxide label rigidly attached to a large protein undergoing ultraslow rotational motions in a lipid bilayer are presented. The echoes are formed by the application of Hahn, COSY, and 2D-ELDOR sequences utilizing both soft and hard microwave pulses. The simulations address the question of whether the echo responses elicited by these sequences are affected by restricted angular excursions of the long axis of the protein relative to the normal to the bilayer plane. The results indicate that all three pulse sequences yield the same quantitative motional information regardless of the nature of the microwave pulses and there is no theoretical reason for preferring one sequence above the others.

Structural and functional degradation of Ca2+:Mg2+-ATPase rich sarcoplasmic reticulum vesicles photosensitized by erythrosin B.

Erythrosin B (Red Dye No. 3) and Rose Bengal photosensitize the destruction of the Ca2+:Mg2+-ATPase pump protein in sarcoplasmic reticulum (SR) vesicles with respective quantum efficiencies of (1.53 +/- 0.19) X 10(-3) and (1.25 +/- 0.18) X 10(-3). Damage to vesicle function was assayed by measurements of increases in passive Ca2+ permeability. Rates of passive Ca2+ movement into the SR lumen were increased by dye photosensitization in proportion to radiation absorbed. Active Ca2+ transport into SR vesicles was blocked independent of radiation absorbed by Erythrosin B and Rose Bengal at free concentrations of 0.69 microM and 1.16 microM, respectively. The photochemical lability of the Ca2+ pump protein and alterations in passive and active Ca2+ transport may be dependent on the concentration of the dye in the membrane. The photosensitization results may have implications with respect to the suitability of Erythrosin B usage in vivo, since the brightness of our irradiation source is comparable to that of sunlight at 480 nm.

[The effect of the blood plasma from irradiated animals on the Ca2(+)- and Mg2(+)-ATPase activity in thymocyte plasma membranes]. / Vliianie plazmy krovi obluchennykh zhivotnykh na aktivnost' Ca2(+)- i Mg2(+)-ATFazy plazmaticheskikh membran timotsitov.

Rats were irradiated at doses 1.5, 4.0, 7.0 and 10 Gy. After 1, 8, 15, 22 and 30 days the effect of blood plasma on activity of Ca(2+)-ATPase and Mg(2+)-ATPase in plasma membrane of thymocytes was investigated. It was found that the raise of irradiation dose leads to increasing of blood plasma effect on membrane-bound enzymes.

[The effect of the repeated irradiation of rats on the Ca2(+)- and Mg2(+)-ATPase activity of thymocyte plasma membranes]. / Vliianie mnogokratnogo oblucheniia krys na aktivnost' Ca2(+)- i Mg2(+)-ATFazy plazmaticheskikh membran timotsitov.

Rats were daily irradiated at doses 0.5 Gy in period of two weeks. The activity of Ca(2+)-ATPase, Mg(2+)-ATPase and the extent of lipid peroxidation in thymus were determined. The peculiarity of changing of enzymes activity demonstrates the dependence of Mg(2+)-ATPase on lipid peroxidation.

[The role of ligands in the effect of exposure to ionizing radiation on Ca2(+)-ATPase and Mg2(+)-ATPase]. / Rol' ligandov pri vozdeistvii ioniziruiushchego izlucheniia na Ca2(+)-ATFazu i Mg2(+)-ATFazu.

The change of Ca(2+)-ATPase and Mg(2+)-ATPase activity in plasma membranes of thymocytes irradiated with doses of 10(2), 10(3) and 10(4) Gy in the presence of Ca2+, Mg2+ and ATP was studied. Stabilizing effect of Ca2+ and Mg2+ on Ca(2+)-ATPase and ATP on Mg(2+)-ATPase under irradiation was established.

[The effect of D2O in irradiation of Ca2+-ATPase]. / Effekt D2O pri obluchenii Ca2+-ATFazy.

Ca(2+)-ATPase from the meat cattle thymocytes plasma membranes in solutions 70% D2O, pH 4.0, 7.0 and 10.0 was irradiated with the doses of 10-10(4)Gr. It was shown that D2O produced stabilizing action on protein macromolecules. The activity of Ca(2+)-ATPase was changed under the influence of ionizing radiation in the presence of D2O.

[The effect of photoexcitation of the electron shell of calcium and magnesium atoms on the ATPase activity]. / Vliianie fotovozbuzhdeniia élektronnykh obolochek atomov kal'tsiia i magniia na ATFaznuiu aktivnost'.

Influence of visible light on Mg-ATPase and Ca-ATPase activity of thymocytes plasma membranes was investigated. It has been shown that illumination of the membranes at lambda = 518 nm 1.8 times increased Mg-ATPase activity and illumination at lambda = 445.5 nm 1.9 times increased Ca-ATPase activity.

[Photoreactivation of Ca2+-ATPase and Mg2+-ATPase after exposure to ionizing radiation]. / Fotoreaktivatsiia Ca2+-ATFazy i Mg2+-ATFazy posle vozdeistviia ioniziruiushchego izlucheniia.

Plasma membranes of thymocytes in doses 10(2), 10(3) and 10(4) Gr were irradiated and subsequently illuminated by lambda = 445,5 nm or lambda = 518 nm light. Then the activity of Ca(2+)-ATPase and Mg(2+)-ATPase was determined. The photomodulation of the electron shell of calcium and magnesium atoms is a factor decreasing the effect of radiation on Ca(2+)-ATPase or Mg(2+)-ATPase.

[Effect of staphylococcal peptidoglycan on the activity of Ca2+-ATP-ase from the sarcoplasmic reticulum in the early stages of ionizing radiation effect]. / Vplyv stafilokokovoho peptydohlikany na aktyvnist' Ca2+-ATP-azi sarkoplazmatychnoho retykulumu hnoho rannikh etapakh promenevoï diï.

It is established that peptidoglycan of Staphylococcus aureus possess superficial activity and can render influence on the functional activity of biomembranes. It tends to increase Ca(2+)-ATP-ase activity in the sarcoplasmic reticulum membranes, but no changes have been observed in case of the enzyme solubilization. The effect of peptidoglycan was more expressed, if it was used in the early period of acute radiation injury (1 and 24 h) in a dose of 0.21 Cl/kg for samples with irradiation-induced decrease of Ca(2+)-ATP-ase activity.

[Effect of ionizing radiation on ATPase activity of thymocyte plasma membranes]. / Vliianie ioniziruiushchevo izlucheniia na ATP-aznye aktivnosti plazmaticheskikh membran timotsitov.

Thymocytes were irradiated by the doses of 4-1000 Gr. Activity of Ca(2+)-ATPase and Mg(2+)-ATP-ase, and lipid peroxidation were determined. It is supposed that changes in Ca(2+)-ATPase activity is connected with the adsorption of irradiation energy, while changes in Mg(2+)-ATPase activity are determined by effect of lipid peroxidation.

[Postradiation changes in Ca2+-ATPase and Mg2+-ATPase in thymocyte plasma membranes]. / Poradiiatsiini zminy aktyvnosty Ca2+-ATPazy i Mg2+-ATPazy pliazmatycnykh membran tymotsytiv.

The rats were irradiated in the doses 1, 5, 4, 7 and 10 Gr and on the 1, 8, 15, 22 and 30 day after the irradiation activity of Ca(2+)-ATPase and Mg(2+)-ATPase and peroxidation lipids in the thymocytes was determined. It was found that postradiation changes in activity of Mg(2+)-ATPase were characterized by a higher sensitivity to the processes of lipids peroxidation as compared to Ca(2+)-ATPase.

[Electrogenic activity of Ca2+-ATPase fragments of the sarcoplasmatic reticulum during the early stages of radiation injury]. / Elektrogennaia aktivnost' Ca2+-ATPazy fragmentov sarkoplazmaticheskogoretikuluma na rannem étape ostrogo luchevogo porazheniia.

It is established that local X-ray irradiation of the rabbit hind limb produces a decrease in Ca2+, Mg2+-ATP-dependent formation of electric potentials difference on the membrane of the sarcoplasmic reticulum (SR). These results agree with the observed decrease in the Ca2+-ATPase activity of SR membranes and increase in their electric conduction after irradiation.

[The effect of ionizing radiation on Ca 2+-ATPase activity from the sarcoplasmic reticulum of rabbit skeletal muscles]. / Vliianie ioniziruiushchei radiatsii na aktivnost' Ca 2+-ATP-azy sarkoplazmaticheskogo retikuluma skeletnykh myshts krolika.

It is established that a decrease in the Ca2(+)-ATPase activity in the sarcoplasmic reticulum membranes 1 and 24 hours after the local X-ray irradiation of rabbit hind limb by a dose of 0.21 Cl/kg is caused mainly by a change in the enzymic microenvironment and a damage of native protein-lipid interactions essential for the functional activity of Ca2(+)-ATPase.