Diazinon and selenium interaction and effect on rat serum cholinesterase activity after an peroral administration

In this study the effect of selenium and diazinon after single and common administration were evaluated. Laboratory rats in the age of 6 weeks (weighting approximately 150 g) were randomly divided into 4 groups. Each group consisted of 10 males. Animals in the first group were administrated with diazinon (Sigma, USA) in the amount of 40 mg/l of drinking water during the time period of 90 days. Animals in the second group were administrated with selenium in the form of na2seo3 (sigma, USA) in the amount of 5 mg/L of drinking water during the time period of 90 days. animals in the third group were given a common mixture of diazinon (sigma, usa) in the amount of 40 mg/l of drinking water and selenium in the form of Na2SeO3 (Sigma, USA) in the amount of 5 mg/L of drinking water during the time period of 90 days. The fourth group served only as a control group and was not administrated with any experimental substance. All of the animals had access to feed and drinking water ad libitum. 91 days after starting of the treatment period, all animals were sacrificed; blood samples were taken from hearts to the sterile tubes and then centrifuged at 3500 rpm for 20 minutes to the blood serum. Catalytic activity of cholinesterase was determined with the using of Bio-La-Test. Principle of this method is based on the process in which cholinesterase splits butyrilthiocholineiodide to butyric acid and thiocholineiodide. Thiocholineiodide reacts with dithiobis-nitrobenzic acid to form a yellow coloration. We observed statistically significant changes of cholinesterase catalytic activity in all of the experimental groups in comparison to control group. Catalytic activity decreased from 3.69 micro kat/l in control group to 1.18 micro kat/l in diazinon treated group. On the other hand, cholinesterase catalytic activity increased from 3.69 micro kat/l in control group to 4.39 micro kat/l in selenium treated group. In contrast to previous experimental group, we detected significant depression of cholinesterase catalytic activity also in diazinon+selenium treated group. cholinesterase activity declined from 3.69 micro kat/l in control group to 1.16 micro kat.