thiouracil and Thyroid-Diseases

The ultrastructure of the degradation of red blood cells (RBCs) in vivo by rat thyroid epithelial cells was studied. Two morphologically distinct degradative pathways appeared evident. The granular pathway was characterized by a finely mottled appearance of RBC phagosomes, first observed about the RBC periphery and later extending to the entire RBC matrix. Such phagosomes became gradually smaller, less electron dense, and indistinguishable from cellular lysosomes. The hemolytic degrative pathway was characterized by a progessive, usually homogenous decrease in the density of the RBC matrix except at the periphery of the RBC, where a thin, dense layer persisted for some time. Such phagosomes often appeared swollen relative to freshly ingested RBCs and resembled RBC ghosts. In later stages, they became irregular, smaller, and gradually indistinguishable from cellular lysosomes. Both degradative pathways were associated with ferritin-like particles. The earliest visualization of ferritin was in the cytoplasm, but in later stages it was also found to be concentrated within lysosomes and phagolysosomes.

Topics: Animals; Cytoplasmic Granules; Epithelial Cells; Erythrocyte Membrane; Erythrocytes; Ferritins; Hemolysis; Hemorrhage; Lysosomes; Male; Phagocytosis; Rats; Thiouracil; Thyroid Diseases; Thyroid Gland

Young adult male Fischer rats were fed 0.25% thouracil in a low-iodine diet to produce hyperplasia of the thyroid gland. The capsule of the thyroid gland increased in thickness from approximately one cell in controls to a substantial multilayered structure. Increase in capsule thickness was noted by 3 days. The cell population of the capsule was largely fibroblasts, but during a period within the interval from 14 to 28 days, the capsule tended to be exceptionally thick and contained many mononuclear leukocytes. At later times the capsule was not quite as thick and the leukocytes largely disapproved. Capillaries developed in the capsule probably by sprouting. The capsule growth was so extensive that certain neighboring tissues were often incorporated into the capsule, including arteries, veins, nerves, striated muscle, and lymph nodes. There was some regional specificity in the development of capsular hyperplasia. Connective tissue increased around the thyroid and parathyroid glands but not between them. Connective tissue in partitions with the thyroid gland also increased in thickness, although the extent of accumulation of cells and intercellular matrix was much less than in the capsule.

Topics: Animals; Blood Vessels; Connective Tissue; Fibroblasts; Hyperplasia; Leukocytes; Lymphatic System; Male; Rats; Thiouracil; Thyroid Diseases; Thyroid Gland

A microhemorrhagic process was consistently observed in association with the induction of thyroid hyperplasia by dietary thiouracil in the rat. This process appeared to involve the extravasation of erythrocytes (RBCs) through hyperplastic capillary walls. Those sites of extravasation which were directly visualized involved endothelial openings of less than 1 mu. These openings were surrounded by endothelial cytoplasm containing a dense fibrous material and were associated with RBC constriction during passage. Extravasated RBCs were most often noted singly or in small groups, either in columns between follicular epithelial cells or embedded amongst the basal epithelial infoldings. Occasionally, extravasated RBCs were also observed within follicular lumens. Extravasated RBCs were usually intact ultrastructurally, but occasionally an apparent hemolytic process was observed, both for RBCs embedded amongst epithelial cells and for those within follicular lumens. The nature and etiology of this microhemorrhagic process are considered in relation to the hypervascularity of the gland, the possibility of capillary wall alterations, the presence of endothelial cell mitoses, and the localization of the process.

Topics: Animals; Epithelium; Erythrocytes; Hemolysis; Hemorrhage; Hyperplasia; Male; Rats; Thiouracil; Thyroid Diseases; Time Factors

Topics: Antithyroid Agents; Chemistry; Contraceptives, Oral; Female; Goiter; History, 19th Century; History, 20th Century; Humans; Hyperthyroidism; Hypothyroidism; Imidazoles; Iodine Radioisotopes; Lithium; Perchlorates; Pregnancy; Thiouracil; Thyroid (USP); Thyroid Diseases; Thyroid Hormones; Thyroid Neoplasms; Thyroxine; Triiodothyronine

Topics: Adolescent; Adult; Age Factors; Antithyroid Agents; Carbimazole; Child; Goiter; Humans; Hyperthyroidism; Hypothyroidism; Iodine; Iodine Isotopes; Propranolol; Thiouracil; Thyroid Diseases; Thyroxine; Triiodothyronine

Topics: Animals; Diet; DNA; Hyperplasia; Iodine; Male; Mice; Organ Size; Polyploidy; Rats; Thiouracil; Thyroid Diseases; Thyroid Gland

Topics: Antithyroid Agents; Chlorides; Cobalt; Goiter; Graves Disease; Humans; Microscopy; Pathology; Thiouracil; Thyroid Diseases; Thyroid Neoplasms; Thyroiditis; Thyroiditis, Autoimmune; Toxicology

Topics: Carcinoma; Endometriosis; Endometritis; Female; Goiter; Graves Disease; Humans; Hyperthyroidism; Iodine Isotopes; Myxedema; Neoplasms; Ovarian Neoplasms; Salpingitis; Thiouracil; Thyroid Diseases; Thyroidectomy; Tuberculosis; Tuberculosis, Female Genital; Uterine Cervical Neoplasms; Uterine Neoplasms

Topics: Diagnosis; Female; Humans; Hyperthyroidism; Hypothyroidism; Pregnancy; Pregnancy Complications; Thiouracil; Thyroid Diseases

Topics: Diencephalon; Goiter; Goiter, Endemic; Humans; Iodine; Thiouracil; Thyroid Diseases

Topics: Child; Female; Goiter; Humans; Hyperthyroidism; Infant; Infant, Newborn; Infant, Newborn, Diseases; Pregnancy; Thiouracil; Thyroid Diseases

Topics: Disease; Hyperplasia; Hypertrophy; Thiouracil; Thyroid Diseases; Thyroid Gland

Topics: Disease; Guinea Pigs; Methylthiouracil; Thiouracil; Thyroid Diseases; Thyroid Gland; Tuberculosis

Topics: Disease; Female; Goiter; Humans; Hyperplasia; Infant; Infant, Newborn; Infant, Newborn, Diseases; Iodides; Iodine; Mothers; Pregnancy; Thiouracil; Thyroid Diseases; Thyroid Gland

Topics: Atrophy; Hashimoto Disease; Humans; Myxedema; Oxyphil Cells; Thiouracil; Thyroid Diseases

Topics: Antineoplastic Agents, Hormonal; Thiouracil; Thiourea; Thyroid Diseases; Thyroid Gland

Topics: Disease Management; Humans; Propylthiouracil; Thiouracil; Thyroid Diseases; Thyrotoxicosis

Topics: Animals; Hyperplasia; Rats; Thiouracil; Thiourea; Thyroid Diseases

Topics: Thiouracil; Thyroid Diseases

Topics: Graves Disease; Humans; Preoperative Care; Syphilis; Thiouracil; Thyroid Diseases

Topics: Hospitals, Public; Thiouracil; Thyroid Diseases

Topics: Thiouracil; Thyroid Diseases

Topics: Hyperthyroidism; Thiouracil; Thyroid Diseases; Thyroid Gland

Topics: Humans; Hypertrophy; Thiouracil; Thyroid Diseases; Thyroid Gland; Thyrotoxicosis