Morphological and biochemical studies on minocycline-induced black thyroid in rats

Tajima, Koji; Miyagawa, Jun‐ichiro; Nakajima, Hitoshi; Shimizu, Masashi; Katayama, Shin–ichi; Mashita, Kazuhiko; Tarui, Seiichiro

doi:10.1016/0041-008x(85)90410-7

Cited by 26 publications

(10 citation statements)

References 9 publications

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“…Affected rats also showed a doserelated reduction in free thyroxine, triiodothyronine and reverse triiodothyronine, the noncalorigenic and biologically inactive cogener of T3. 319,324,325 The pigment possesses histochemical characteristics of melanin. 316 A similar discoloration was subsequently reported in the thyroid gland in humans on long-term treatment with minocycline.…”

Section: Drug-induced Thyroiditismentioning

confidence: 99%

“…315 Pigmentation Coal black pigmentation of the thyroid gland was initially reported in rats, mice, dogs and monkeys given the semi-synthetic tetracycline derivative minocycline for periods longer than one month. 319,324 The Perls reaction for iron and the oil-red-O stain are usually negative, although in some human cases the pigment appears to be mixed with lipofuscin. 317À322 Unlike tetracycline, minocycline is particularly well distributed to the thyroid.…”

Section: Drug-induced Thyroiditismentioning

confidence: 99%

“…317À322 Unlike tetracycline, minocycline is particularly well distributed to the thyroid. 324 The cause of the pigmentation and its effect on thyroid function is uncertain. Histological examination reveals finely granular dark brown pigment in the apical cytoplasm of the follicular epithelium.…”

Section: Drug-induced Thyroiditismentioning

confidence: 99%

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Endocrine Glands

Greaves¹

2012

Histopathology of Preclinical Toxicity Studies

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Section: Drug-induced Thyroiditismentioning

confidence: 99%

Section: Drug-induced Thyroiditismentioning

confidence: 99%

See 1 more Smart Citation

Endocrine Glands

Greaves¹

2012

Histopathology of Preclinical Toxicity Studies

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“…Doses higher than 25 mg/kg induce body mass reduction, skin irritation, rise of hepatic enzymes and triglycerides and a slight decrease in potassium excretion (Noble et al 1967;Bocker et al 1991;Smith et al 2003). Minocycline (100 mg kg −1 day −1 for 35 days) induces thyroid pigmentation associated with functional deficits at a high dose (Tajima et al 1985). In experimental animals, minocycline is lethal (DL 50 , 3,600 mg/kg) at doses that are irrelevant to studies on pain and neurodegeneration (Blum et al 2004).…”

Section: Pharmacokinetic and Toxicological Profiles Of Minocycline Rementioning

confidence: 98%

Tetracyclines and pain

Bastos

Oliveira

Watkins

et al. 2012

Naunyn-Schmiedeberg's Arch Pharmacol

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Tetracyclines are natural or semi-synthetic bacteriostatic agents which have been used since late 1940s against a wide range of gram-positive and gram-negative bacteria and atypical organisms such as chlamydia, mycoplasmas, rickettsia, and protozoan parasites. After the discovery of the first tetracyclines, a second generation of compounds was sought in order to improve water solubility for parenteral administration or to enhance bioavailability after oral administration. This approach resulted in the development of doxycycline and minocycline in the 1970s. Doxycycline was included in the World Health Organization Model List of Essential Medicines either as antibacterial or to prevent malaria or to treat patients with this disease. Additional development led to the third generation of tetracyclines, being tigecycline the only medicine of this class to date. Besides antibacterial activities, the anti-inflammatory, antihypernociceptive and neuroprotective activities of tetracyclines began to be widely studied in the late 1990s. Indeed, there has been an increasing interest in investigating the effects induced by minocycline as this liposoluble derivative is known to cross the blood-brain barrier to the greatest extent. Minocycline induces antihypernociceptive effects in a wide range of animal models of nociceptive, inflammatory and neuropathic pain. In this study, we discuss the antihypernociceptive activity of tetracyclines and summarise its underlying cellular and molecular mechanisms.

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“…Since the first report of "black thyroid," a condition marked by discoloration due to brown deposits associated with minocycline therapy in 1976,1 additional cases have been reported, 2-4 but the condition has been investigated primarily by histopathological methods, and its pathogenesis is still unclear. 5-7 While minocycline is suggested to interfere with thyroid function and alter thyroxine metabolism in animals, 7,8 there is no evidence of such an effect on thyroid function in humans.We therefore conducted a prospective study to investigate thyroid hormone levels in patients undergoing minocycline therapy.…”

Section: Introductionmentioning

confidence: 99%