THE ROLE OF SOME ENDOGENOUS AND EXOGENOUS NITRIC OXIDE DONORS AS A POSSIBLE ANTIDOTE AT POISONING FROM CARBAMATE PESTICIDES
RADOY I. IVANOV1*, ELITZA T. DENCEVA2
1-Department of Physiology of animals and human, Sofia university “St. Kliment Ohridski”, Faculty of Biology
2-Department of Zoology and anthropology, Sofia university “St. Kliment Ohridski”, Faculty of Biology
* Corresponding author: radoy_011@abv.bg
Keywords: Acetylcholinesterase; butyrilcholinesterase; nitric oxide; L-Arginine; Na-Nitroprusside; organophosphorus and carbamate pesticides
Abstract: Enzyme mapping of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) in certain segments of the brain of rabbit and rat was done in this work. The differences in enzyme activity, characterized histologically was attributed to the BChE, an enzyme, which plays a major role in the defense mechanisms of the body and mainly the nervous system against poisons that damage cholinergic functions.
It was first found that certain nitric oxide donors, such as L-Arginine and Na-Nitroprusside stimulate the activity of both esterases – AChE and BChE. This stimulatory effect of L-Arginine (respectively of nitric oxide (NO) on the AChE activity ranges from several percents to 1-2 fold compared to the controls. The activation of BChE activity reaches an increase of 3-8 folds. This stimulation of enzyme activity was attributed to the influence of NO. The effects of Na-Nitroprusside are biphasic – activation at very low concentrations (0.05-0.1 mM) and progressive concentration-dependent inhibition with increasing concentrations of the reagent. This inhibitory effect is due to specific metabolic products released during decomposition of Na-Nitroprusside.
The stimulating effect of NO donors L-Arginine and Na-Nitroprusside on the studied enzyme activity were considered significant. Therefore, they can be used as an effective antidote to poisoning by organophosphate and carbamate pesticides, and intoxication by chemical warfare agents.