Evdokimova O.V., Gorodetskaya I.V.
The effect of experimental hypothyroidism and L-thyroxine low doses on the activity of aminotransferases and gamma-glutamyltransferase in blood under the influence of stressors of different origin
Abstract. In the experiments on 120 adult white mongrel male rats with body weight 200–250 g it has been shown that physical stress (exposure at t 4°C for 30 minutes) causes the increase in serum activity of alanine aminotransferase (ALT) (by 11%). Chemical exposure (single intragastric dose of 25% ethanol solution at the dose of 3,5 g/kg) increases the activity of ALT (by 28%) and, especially, that of gamma-glutamyltransferase (GGT) (by 176%). Emotional stress (free swimming in the cage (FSC) for 30 minutes) is accompanied by the increase in the activity of ALT (by 44%), and aspartate aminotransferase (by 128%), and GGT (by 98%). Introduction of mercazolil (intragastrally 25 mg/kg for 20 days) per se causes the increase in the activity of the studied enzymes and determines its most significant increase under all actions. Administration of L-thyroxine in small doses (intragastrally 1,5–3,0 µg/kg for 28 days) by itself does not affect the activity of enzymes in the blood and at the same time prevents the increase in ALT activity during cold and chemical exposure and in GGT activity under FSC stress, under which it significantly limits the increasing of aminotransferases activity as well as GGT activity under chemical stress. The results testify to the stabilization of cell membranes by iodine-containing thyroid hormones under stress of different origin.
Key words: iodine-containing thyroid hormones, aminotransferases, gamma-glutamyltransferase.
