Study of aerobic granulocyte functional activity in the presence of a radiosensitizer (metronidazole).

The in vitro effects of metronidazole on the production of reactive oxygen species by polymorphonuclear (PMN) cells were studied by means of nitroblue tetrazolium and luminol-dependent chemiluminescence. At therapeutic doses of metronidazole (4.98-24.86 microg/mL) significant inhibition of the production of reactive oxygen species was noted in both methods. The inhibitory effect was in a dose-dependent pattern. The data suggest a scavenging mechanism of metronidazole on reactive oxygen species generated by PMN.

Study of aerobic granulocyte functional activity in the presence of a radiosensitizer [metronidazole]

The in vitro effects of metronidazole on the production of reactive oxygen species by polymorphonuclear [PMN] cells were studied by means of nitroblue tetrazolium and luminol-dependent chemiluminescence. At therapeutic doses of metronidazole [4.98-24.86 microg/mL] significant inhibition of the production of reactive oxygen species was noted in both methods. The inhibitory effect was in a dose-dependent pattern. The data suggest a scavenging mechanism of metronidazole on reactive oxygen species generated by PMN

In vitro effect of different non-steroidal anti-inflammatory drugs on human polymorphonuclear leukocyte activity measured by luminol-dependent chemiluminescence of the whole blood.

OBJECTIVE: To define the well-known variability in the effects of non-steroidal anti-inflammatory drugs and to search for predictors of such variability using an in vitro model. METHODS: Polymorphonuclear leukocyte activity was measured by luminol-dependent chemiluminescence of the whole blood using barium sulphate as a stimulator. Blood was taken from 40 apparently healthy volunteers (22 males and 18 females; their age ranged from 20-50 years). Drugs (indomethacin 10 ug/ml, aspirin 300 ug/ml, ibuprofen 25 ug/ml or diclofenac 8 ug/ml) were added into the blood of each individual in vitro. The chemiluminescence was measured in a photon counting system. RESULTS: There was a marked inter and intra individual variation in the chemiluminescence response to the 4 non-steroidal anti-inflammatory drugs, added in vitro. The variation exhibited a continuous pattern. No statistically significant correlation was found between the in vitro effect of one non-steroidal anti-inflammatory drug and the other 3 drugs, nor between the effect of each drug and factors like age, sex, weight, height, packed cell volume, hemoglobin percentage and white blood cell count. Subjects with hemoglobin-AS type (number = 9) responded mainly by enhancement to indomethacin and diclofenac. When the number of subjects rather than the average net effect was compared according to blood groups, those with blood group A showed chemiluminescence responses towards enhancement with indomethacin and diclofenac and blood group O with aspirin. A consistent pattern of enhancement and inhibition was evident; enhancements and inhibitions by any 2 drugs involve a seemingly constant proportion of subjects. CONCLUSION: Luminol-dependent chemiluminescence responses of polymorphonuclear leukocyte activity could be a good in vitro model to study the variability in response to non-steroidal anti-inflammatory drugs. Characteristics of each individual are not able to predict the pattern of variability. Abnormal hemoglobin and the type of blood group seem to be an interesting area for research.

Lucigenin chemiluminesence. A new approach to study the redox activity of Ehrlich ascetic tumor cells.

OBJECTIVE: To study the mechanism and to measure the oxygenation/reduction activity of Ehrlich ascetic tumor cells in an isotonic solution by means of lucigenin dependent chemiluminescence. METHODS: All the measurements of the chemiluminescence redox activity of Ehrlich ascetic tumor cell samples in suspension medium, were carried out using a photon counting system especially designed to the purpose. The areas under the chemiluminescence kinetic curves were measured at different cell physiological conditions and at different agents concentrations effect. RESULTS: The rates of lucigenin chemiluminescence redox functional activity of Ehrlich ascetic tumor cells were significantly different from normal oxygenation/reduction activity at different physiological environments of Ehrlich ascetic tumor cells suspension conditions (i.e. cell membrane permeability changes, presence and absence of oxidative or reductive agents at different concentrations and oxy/hydroxy free radical protective agents). CONCLUSION: The results explain more fully the mechanism and the value of a lucigenin dependent chemiluminescence probe of the redox functional activity of Ehrlich ascetic tumor cells (at different physiological conditions of suspension).

Inhibition of luminol-dependent chemiluminescence of human granulocytes by low doses of inorganic mercury.

HgCl2, added in vitro to human granulocytes in whole blood, caused a marked inhibitory effect on the luminol-dependent chemiluminescence induced by BaSO4 crystals in suspension of these cells. The effect was both dose- and time-dependent when BaSO4 was used to stimulate the oxidative burst in granulocytes. Incubation with the highest concentration of HgCl2 used (10 mmol/L), however, did not cause disruption of the membranes of granulocytes. The effect of HgCl2 on the granulocytes was irreversible following washing of the HgCl2-treated cells with phosphate buffered saline. HgCl2 did not affect chemiluminescence produced when luminol was excited by oxidative hydrogen peroxide in a cell-free medium. These results suggest that some of the toxicity of HgCl2 may be greater than mediated by an action on the phagocytic immune system.

Inhibition of luminol-dependent chemiluminescence of human granulocytes by low doses of inorganic mercury

HgCl2, added in vitro to human granulocytes in whole blood, caused a marked inhibitory effect on the luminol-dependent chemiluminescence induced by BaS04 crystals in suspension of these cells. The effect was both dose- and time-dependent when BaS04 was used to stimulate the oxidative burst in granulocytes. Incubation with the highest concentration of HgCl2 used [10 mmol/L], however, did not cause disruption of the membranes of granulocytes. The effect of HgCl2 on the granulocytes was irreversible following washing of the HgCl2-treated cells with phosphate buffered saline. HgCl2 did not affect chemiluminescence produced when luminol was excited by oxidative hydrogen peroxide in a cell-free medium. These results suggest that some of the toxicity of HgCl2 may be greater than mediated by an action on the phagocytic immune system

Mercury in some commercial fish from Kuwait: a pilot study.

We investigated the total mercury content in the muscles, liver and gonads of eight commercial fish from Kuwait. Mercury concentrations in the muscle of all the fish were below the action level of 1 microgram g-1 (wet weight) set by the United States Food and Drug Administration. However, large specimens of Epinephelus tauvina (Hamoor) and Lutjanus Coccineus (Hamrah) showed concentrations which were close to the action level. The relationship between mercury concentration and fish age and length was in the form of an exponential correlation (Y = aXb), in which concentration increases with an increase in fish age or length. Correlation coefficients obtained ranged between 0.65 and 0.86.

Modification of ultrasound induced changes in mammalian cells by increased viscosity of medium and increased ambient pressure.

Ehrlich ascites tumour cells (E.A.T.) in suspension were exposed to ultrasound of frequency 1x5 MHZ, intensities 1x4, 2x8 W/cm2 for 60 min at 37 degrees C. The suspensions of E.A.T. cells were contained in Perspex vessels with Melinex windows, situated in the near field of a piezoceramic transducer. Subsequently the rate of net influx of Rb-86 ions was studied over a period of 90 min. A reduced Rb-86 activity of insonated cell populations was observed compared to controls. Similar experiments were carried out involving E.A.T. cells suspended in isotonic medium containing 0x25 per cent agar (2x1 centipoise). No significant depression of uptake of Rb-86 ions was observed at 2x8 W/cm2, 1x5 MHZ. Cells insonated in normal medium at 1x9 atmos. helium pressure subsequently showed no depression of Rb-86 uptake, compared to controls, following insonation at 2x8 W/cm2, 1x5 MHZ for 60 min.