[The effect of carbimazole on lactate dehydrogenase isoenzymes and thyroid hormone levels in sheep].

The oxidative processes in the organism are activated by hormones of the thyroid gland. The pyruvate-lactate component catalyzed by lactate dehydrogenase presents one of the important oxidic-reductive systems in the animal organism of biochemical importance (EC. 1.1.1.27). In certain cases of the thyroid gland disturbances antithyroid drugs, such as derivatives of thiouracil, mercaptoimidazole and some others may be used for the treatment of men and animals (Marchant et al., 1979; Negwer, 1987). In the present study, the activity changes of lactate dehydrogenase isoenzymes in the blood plasma of young rams and ewe hoggets in experiments with carbimasole [carbimasolum(1-carbaethoxy-3-methyl-2-thioimidazolum) ] have been studied. The dose of carbimasole at the time of sampling (May, 1993) was 7O mg per animals and day. In May, no significant differences in T3 and T4 concentrations in the serum of experimental and control animals in males and females were found (Tab. 1). The T3 concentrations in the experimental group of young rams were 0.56 +/- 0.21 nmol/l (n = 3), in ewe hoggets 0.70 +/- 0.19 nmol/l (n = 6). The T4 concentrations in young rams were 39.15 +/- 24.15 nmol/l (n = 3), in ewe hoggets 48.6 +/- 15.3 nmol/l (n = 6). Out of lactate dehydrogenase isoenzymes, only LD4 exhibited significant differences (P < 0.02) in the blood plasma of ewe hoggets (Tab. I). In the course of these months, no clinical signs of hypothyrosis were observed in experimental animals.