[Effect of angiotensin on the ultrastructure of the rat thyroid gland]

Four hours after administering angiotensin to rats accumulation of radioactive iodine by the thyroid glands is inhibited. Angiotensin produces the contraction of thyroid arterioles. The cytoplasm of endotheliocytes of the perifollicular exchange microvessels becomes dense and luminar surfaces very involuted. Administration of angiotensin also leads to the changes in the ultrastructure of thyrocytes. The cisternae of the granular endoplasmic network get enlarged, the number of membrane-associated ribosome and mitochondria diminishes, that of lysosomes increases.