The use of micronucleus test for detection of genotoxic damage to the thyroid gland.

We studied the possibility of using the micronucleus test in in vivo experiments on the model of rat follicular thyrocytes prestimulated to cell division (hemithyroidectomy). Single administration of N-nitroso-N-methylurea produced a significant dose-dependent effect on micronucleus formation in thyrocytes and polychromatophilic erythrocytes of the bone marrow. The test system allowed us to reveal a cumulative effect of 2-fold and 4-fold treatment with the mitogen in low or subthreshold doses on the thyroid gland.

[Thyroid regeneration in various localizations of resected fragments of the organ].

Structure and function of the regenerating thyroid fragment were studied in 18 adult white rats 30 days after partial resection of centromedial or peripheral fragments of the lobes similar in size using quantitative methods (organometry, histometry, measurements of blood serum hormones). The volume of glandular tissue removed in two series of experiments was 40 and 75% of the total thyroid mass of experimental animals. Centromedial portions of the thyroid of intact rats were characterized by greater follicular epithelium volume (by 10%) and C-cell content per section area (six-fold), as well as by a lesser mean diameter of the follicles (by 26%) and colloid volumic fraction (by 40%) in comparison with the peripheral segments.

[Influence of novodrin and obsidan on the secretory activity of tissue basophils of the thyroid and parathyroid glands].

The task was to investigate secretory activity of sets of tissue basophils of the thyroid and parathyroids during administration of isoproterenol (novodrin) and propranolol (obsidan); 32 rats, divided into 2 groups, were given a single intraperitoneal injection of 20 mg of isoproterenol (the 1 st group) and 2.5. mg of propranolol (the 2nd group) with their subsequent decapitation with a 12-minute interval for 3 h.