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Morphological and biochemical studies on minocycline-induced black thyroid in rats
- Source :
- Toxicology and Applied Pharmacology. 81:393-400
- Publication Year :
- 1985
- Publisher :
- Elsevier BV, 1985.
-
Abstract
- The thyroid glands of the rats treated with 100 mg/kg/day of minocycline for 35 days showed black discoloration. In these thyroids, brown pigment granules were seen in the follicle epithelial cells, and they histochemically stained in the same manner as melanin. By electron microscopy, the deposition of the electron-dense material first occurred in lysosome-like granules and, with further administration, was observed also in the rough endoplasmic reticulum in some cells. Thin-layer chromatography showed that the R f value of the extract from minocycline-treated rat thyroid was the same as that of the black substance obtained by mixing minocycline and 3% hydrogen peroxide but different from that of melanin. In minocycline-treated rats, the release of thyroxine (T 4 ) from perifused thyroids was significantly less than that from control, and the analysis of iodoamino acids showed an increased monoiodotyrosine fraction. Thus, (1) the pigment of thyroid in minocycline-treated rats was demonstrated to be a metabolic derivative of minocycline itself and (2) minocycline may interfere with thyroid function in high-dose, long-term treatment.
- Subjects :
- Male
medicine.medical_specialty
Thyroid Gland
Administration, Oral
Thyrotropin
Minocycline
Toxicology
Iodine Radioisotopes
Melanin
chemistry.chemical_compound
Follicle
Internal medicine
Cyclic AMP
medicine
Animals
Hydrogen peroxide
Melanins
Pharmacology
Pigmentation
Chemistry
Endoplasmic reticulum
Thyroid
Rats, Inbred Strains
Monoiodotyrosine
Rats
Microscopy, Electron
medicine.anatomical_structure
Endocrinology
Tetracyclines
Chromatography, Thin Layer
Thyroid function
medicine.drug
Subjects
Details
- ISSN :
- 0041008X
- Volume :
- 81
- Database :
- OpenAIRE
- Journal :
- Toxicology and Applied Pharmacology
- Accession number :
- edsair.doi.dedup.....6da7c1d562316e74feebcfaa2ec45542