Analysis of thyroid gland microvascularization in rats induced by ingestion of potassium bromide: a scanning electron microscopy study.

The microvascularization of the thyroid gland in rats was studied in animals following ingestion of potassium bromide in various concentrations in drinking water (15, 50 or 100 mg/l) over a period of either 16 or 66 days. Accordingly, animals were divided into six study groups and one control group. Microvascularization was compared among the groups. The pattern of thyroidal follicle distribution within the blood vessels was evaluated by scanning electron microscopy. Animals that ingested potassium bromide presented an increased density and number of meshes in the capillary network of the follicle. The peripheral vessels showed flattening of the walls and in the central portion of the follicle, the distribution of the capillary network did not undergo any morphologic alteration.