Nitric oxide production inhibited by xenobiotic compounds in the protozoan Paramecium primaurelia

Photochem & Photobiology

Benedicenti

Ferrando

et al. 2016

Self Cite

In Paramecium, cilia beating is correlated to intracellular calcium concentration ([Ca ]i) and nitric oxide (NO) synthesis. Recent findings affirm that photobiomodulation (PBM) can transiently increase the [Ca ]i in mammalian cells. In this study, we investigated the effect of both 808 and 980 nm diode laser irradiated with flat-top hand-piece on [Ca ]i and NO production of Paramecium primaurelia, to provide basic information for the development of new therapeutic approaches. In the experiments, the laser power in CW varied (0.1; 0.5; 1; and 1.5 W) to generate the following respective fluences: 6.4; 32; 64; and 96 J cm . The 6.4 J cm did not induce PBM if irradiated by both 808 and 980 nm diode laser. Conversely, the 32 J cm fluence had no effect on Paramecium cells if irradiated by the 808 nm laser, while if irradiated by the 980 nm laser induced increment in swimming speed (suggesting an effect on the [Ca ]i, NO production, similar to the 64 J cm with the 808 nm wavelength). The more evident discordance occurred with the 96 J cm fluence, which had the more efficient effect on PBM among the parameters if irradiated with the 808 nm laser and killed the Paramecium cells if irradiated by the 980 nm laser. Lastly, the 980 nm and 64 or 96 J cm were the only parameters to induce a release of stored calcium.

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Photobiomodulation by Infrared Diode Laser: Effects on Intracellular Calcium Concentration and Nitric Oxide Production of Paramecium

Photochem & Photobiology

Benedicenti

Ferrando

et al. 2016

Self Cite

“…Our work suggests considering, in future regulations, about the use of pesticides as their toxic effect on non-target organisms is strongly influenced by climate temperatures that vary from season to season and from country to country and are constantly influenced by human activity. In addition, there is need for a new consideration of the protozoa, which takes into account recent researches about the presence in this microorganism of classical neurotransmitters [13,19,32,41,42] that, similar to those in animals, make protozoa an innocent target of neurotoxic pesticides in the battle against pest crops.…”

Section: Discussionmentioning

confidence: 99%

The Effects of Temperature Variation on the Sensitivity to Pesticides: a Study on the Slime Mould Dictyostelium discoideum (Protozoa)

2014

Microb Ecol

Self Cite

Slime moulds live in agricultural ecosystems, where they play an important role in the soil fertilization and in the battle against crop pathogens. In an agricultural soil, the amoebae are exposed to different stress factors such as pesticides and weather conditions. The use of pesticides increased up from 0.49 kg per hectare in 1961 to 2 kg in 2004, and the global greenhouse gas emission has grown 70% between 1970 and 2004 leading to a global fluctuation of average surface temperature. Therefore, the European Directive 2009/128/EC has led to a new approach to agriculture, with the transition from an old concept based on high use of pesticides and fossil fuels to an agriculture aware of biodiversity and health issues. We studied the effects of temperature variations and pesticides on Dictyostelium discoideum. We measured the fission rate, the ability to differentiate and the markers of stress such as the activity and presence of pseudocholinesterase and the presence of heat shock protein 70. Our results highlight how the sensitivity to zinc, aluminium, silver, copper, cadmium, mercury, diazinon and dicofol changes for a 2 °C variation from nothing/low to critical. Our work suggests considering, in future regulations, about the use of pesticides as their toxic effect on non-target organisms is strongly influenced by climate temperatures. In addition, there is a need for a new consideration of the protozoa, which takes into account recent researches about the presence in this microorganism of classical neurotransmitters that, similar to those in animals, make protozoa an innocent target of neurotoxic pesticides in the battle against the pest crops.

“…36,37 This activity can also be produced by enzymes other than NOS. 38–41 Among protozoa, NOS activity and NO production have been identified and characterised in Paramecium , 25,26,42 Leishmania donovani , 19 Physarum polycephalum , 22 Trypanosoma cruzi , 21 as well as in Dictyostelium discoideum ( D. discoideum ). In these protozoa, NO-generating compounds: i) inhibit its aggregation and differentiation without altering cyclic guanosine monophosphate (cGMP) production 43 by preventing initiation of cyclic adenosine monophosphate (cAMP) pulses; 44 ii) stimulate adenosine diphosphate (ADP)-ribosylation of a 41 kDa cytosolic protein; 45,46 and iii) regulate the glyceraldehyde-3-phospate dehydrogenase activity.…”

Section: Introductionmentioning

confidence: 99%

Detection and characterisation of NAD(P)H-diaphorase activity in Dictyostelium discoideum cells (Protozoa)

Chessa

2012

Eur J Histochem

In Dictyostelium discoideum (D. discoideum), compounds generating nitric oxide (NO) inhibit its aggregation and differentiation without altering cyclic guanosine monophosphate (cGMP) production. They do it by preventing initiation of cyclic adenosine monophosphate (cAMP) pulses. Furthermore, these compounds stimulate adenosine diphosphate (ADP)-ribosylation of a 41 kDa cytosolic protein and regulate the glyceraldehyde-3-phospate dehydrogenase activity. Yet, although D. discoideum cells produce NO at a relatively constant rate at the onset of their developmental cycle, there is still no evidence of the presence of nitric oxide synthase (NOS) enzymes. In this work, we detect the nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) activity in D. discoideum and we characterise it by specific inhibitors and physical-chemical conditions that allegedly distinguish between NOS-related and -unrelated NADPH-d activity.