Induction of metallothioneins by ethanol and morphine

Metallothioneins take part in homeostasis of the ions of metals which are necessary for proper metabolism of the organism (zinc, copper), biosynthesis regulation and zinc proteins activity as well as in the processes of detoxication of cells from toxic metals. Besides, they also protect cells from the reactive forms of oxygen, radiation, electrophilic pharmacological agents used in the cancer therapy, and the mutagenes. The aim of the study was to determine the level of metallothioneins in tissue of rats intoxicated with ethanol and morphine. The experiment was to state whether the applied narcotic agents cause the change in the metallothionein's level in the liver, brain and kidneys of the intoxicated animals. The experiment was carried out on 6-month-old rats of Wistar strain, weighing 150-200 g, which were given ethanol intragastrically and morphine intraperitoneally for 5 days. The metallothioneins level in tissues was determined by cadmium-hemoglobin affinity assay, using the cadmium isotope (109 Cd). It was found that the level of metallothioneins in the group of animals intoxicated with ethanol was elevated (in kidneys it increased 1.5 times, in the liver--3.5, and in the brain--10 times). In the case of morphine-intoxicated rats the level of metallothioneins also increased in all the examined tissues; the increase was fifteen-fold in the brain, threefold in the liver, and twofold in kidneys. It results from the above studies that the narcotic agents used for the animals' intoxication produce the increase in the level of metallothioneins in all the examined rats' tissues. The examinations prove different force of metallothioneins induction according to a tissue.