Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Egypt. J. Histol. Vol. 32, No. 1, June, 2009: 101 - 108 (ISSN: 1110 - 0559) Original Article Light and Electron Microscopic Study on the Effect of Lithium Carbonate on the Thyroid Gland of Adult Male Albino Rat Nafisa A. El-Bakary and Gehan M. Soliman Histology Department, Faculty of Medicine, Tanta University ABSTRACT Introduction: Lithium carbonate is the treatment of choice for acute manic episodes. It is often referred to as an antimanic drug as it prevents mood swings in patients with manic- depressive disorder. Thyroid disturbances during lithium treatment had been reported. Aim of the Work: This research was performed to study the effect of lithium carbonate on the thyroid gland of albino rat and the possibility of recovery after drug withdrawal. Materials and Methods: Thirty adult male albino rats were divided into three equal groups; Group I (Control Group), group II received lithium carbonate at a daily dose of 14.4 mg for each rat for 6 weeks orally and group III received the same dose of lithium carbonate as group II and then left untreated for another 6 weeks to study the possibility of recovery after the drug withdrawal. The specimens were prepared for light and electron microscopic examination. Results: Sections of lithium carbonate treated rats showed enlarged irregular shaped thyroid follicles with papillary infoldings projecting into the follicular lumena. Detached and desquamated follicular cells were seen in the follicular colloid. The follicular cells showed apparent hyperplasia and bizarre-appearing nuclei. The interstitial tissue showed cellular infiltration, presence of deeply eosinophilic large cells and fibrosis in some specimens. Ultrastructurally, there was cellular debris in the follicular lumena. Some follicles showed dark follicular cells containing electron dense cytoplasm and indistinct organelles. The above structural changes were much less pronounced in group III (Recovery Group). Conclusion: Lithium carbonate induced histological changes in the thyroid gland of albino rat and most of these changes were seen to be improved after withdrawal of the drug. So, the use of this drug should be justified in clinical situation under direct medical supervision. Key Words: Lithium carbonate, thyroid gland, Corresponding Author: Nafisa A. Elbakary histopathology. Tel.: 0109171524 E-mail: [email protected] INTRODUCTION excreted unchanged in the urine4. It has been reported that lithium induced gastrointestinal, neuromuscular and endocrine adverse effects in patients taking it5. Lithium salts are used as mood stabilizing drugs. They have a role in the treatment of depression and mania in both acute and long term conditions1. Lithium carbonate is the treatment of choice for acute manic episodes. It is often referred to as an anti-manic drug. It prevents mood swings in patients with manic-depressive disorder2. International multi center studies yield strong evidence that mortality and suicide rates could be lowered by long- term lithium treatment3. The thyroid gland is a highly vascular organ. The pathway of thyroid hormones synthesis, transport of secretion in the circulation and their metabolism offer numerous targets for drug interaction6. Thyroid disturbances during lithium treatment had been reported6. However, there have been few reports describing the histological alterations of the thyroid gland during lithium treatment. This research was carried out to study the effect of lithium carbonate on the structure of the thyroid gland of albino rat and the possibility of recovery after drug withdrawal. Lithium carbonate is virtually totally absorbed from the gastrointestinal tract within 18 hours of oral administration, with peak blood levels achieved in 2 to 4 hours. Its tissue uptake is not uniform, with levels in the brain, thyroid and saliva exceeding plasma levels. Lithium is not bound to proteins or metabolized but 9 (1134-2009) 101 Light and Electron Microscopic Study on the Effect of Lithium Carbonate on the Thyroid Gland MATERIALS AND METHODS of thyroid follicles of variable sizes and their lumena contained colloid. The follicles were lined by simple cuboidal epithelium (follicular epithelium) (Fig. 1). Mallory’s trichrome stained sections showed little amount of connective tissue in interstitial tissue between the thyroid follicles (Fig. 2). This research was carried out on 30 adult male albino rats ranging in weight from 150-200 grams. All animals were maintained on a standard diet and water and kept under suitable conditions. They were divided into three groups: Group II: Examination of specimens obtained from lithium-treated animals showed morphological changes in the thyroid glands. Many specimens showed irregular shaped follicles with papillary infoldings projecting into the follicular lumena. Extra follicular colloid was evident in the inter follicular spaces (Fig. 3). Some follicles were lined by simple squamous, others were lined by simple cuboidal or tall columnar epithelium (Figs. 4&5). Bizarre-appearing nuclei in the form of pleomorphism and hyperchromasia were also observed in the lining epithelium of some follicles and scalloped edges of the colloid of some follicles were detected. (Fig. 5). Detached and desquamated follicular cells were present in the follicular colloid. Some follicles were filled with aggregates of these desquamated follicular cells (Figs. 6&7). Pinched apical parts of follicular cells associated with apical vacuolation were observed (Figs. 8&9).Cellular infiltration in the interstitial tissue was detected (Fig. 9). Deeply eosinophilic large cells were present in the interstitial tissue in many specimens (Fig. 10). Mallory’s trichrome stained sections showed interstitial fibrosis in some specimens (Fig. 11). Group I (Control Group): Included 10 rats which were further subdivided into 2 subgroups. Subgroup A (negative control animals) included 5 animals being kept without any treatment. Subgroup B (positive control) included 5 animals each received distilled water by the same route, dose and duration as lithium carbonate treated animals. Group II: Included 10 rats, each received lithium carbonate (Prianil CR) at a daily dose of 14.4 mg7,8 for 6 weeks. This drug is manufactured by EL-Nile Company. It is present in the form of tablets of 400 mg. The drug was dissolved in distilled water and the calculated dose was given per mouth using feeding tubes. Group III: Included 10 rats, each received the same dose of lithium carbonate as group II for the same period and then left untreated for another 6 weeks to study the possibility of recovery after the drug withdrawal. At the expected time, the animals were anaesthetized with diethyl ether and perfused intracardially with 4% paraformaldehyde in 0.1 M phosphate buffered solution (PH 7.2) containing 1 % glutaraldehyde solution. The thyroid glands were dissected out and some specimens were processed for light microscopy and stained with haematoxylin and eosin and Malloryʼs trichrome9. Group III: Examination of specimens obtained from group III (Recovery Group) showed regression of the lesions in many specimens. However, some thyroid follicles still showed papillary infoldings and irregular outlines (Fig. 12). Mallory’s trichrome stained sections showed interstitial fibrosis in some sections (Fig. 13). Parallel tissue specimens were processed for electron microscopy by immediate immersion for one hour in a glutaraldehyde fixative based on 0.1 M phosphate buffer (pH 7.2). They were then washed three times (5 minutes each) with phosphate buffer followed by postfixation in 1 % phosphate buffered osmium tetroxide for thirty minutes at room temperature. After dehydration in ascending grades of ethyl alcohol, the specimens were embedded in Epon–araldite mixture. Ultrathin sections were cut with ultramicrotome using a diamond knife and stained with uranyl acetate and lead citrate10 to be examined by the transmission electron microscope at Faculty of Science, Ain-Shams University. Electron microscopic results: Group I: Electron microscopic examination of specimens obtained from the control animals showed a part of thyroid follicle composed of cuboidal follicular cells with rounded nuclei. The apical surfaces of these cells showed small microvilli protruded into the follicular lumen that contained colloid (Fig. 14). Group II: Examination of specimens obtained from lithium-treated animals revealed cellular debris in the follicular lumen (Figs. 15&16). Some follicles showed dark follicular cells which contained electron dense cytoplasm and indistinct organelles (Fig. 17). RESULTS Group III: Examination of specimens obtained from animals of recovery group showed that thyroid follicles appeared more or less as the control group but some follicular cells showed dense bodies in their cytoplasm (Fig. 18). Light microscopic results: Group I: Light microscopic examination of specimens from all control animals showed the same histological structures. The thyroid gland consisted 102 Nafisa A. El-Bakary and Gehan M. Soliman Fig. 1: A photomicrograph of a section of thyroid gland of control group showing thyroid follicles lined by simple cuboidal epithelium (→) and containing colloid. H&E., Mic. Mag. X 400. Fig. 2: A photomicrograph of a section of thyroid gland of control group showing little amount of connective tissue in interstitial tissue (→). Mallory's trichrome, Mic. Mag. X 400. Fig. 4: A photomicrograph of a section of thyroid gland of lithium treated rats showing irregular shaped follicles, some of them are lined by simple squamous epithelium (→) and others are lined by simple columnar epithelium (►). Notic the presence of papillary projections in some follicles. H&E., Mic. Mag. X 200. Fig. 5: A photomicrograph of a section of thyroid gland of lithium treated rats showing parts from thyroid follicles one is lined by tall columnar epithelium (►) and the other is lined by cuboidal epithelium with pleomorphic nuclei (→). Notice the scalloped appearance of the colloid edges (*). H&E., Mic. Mag. X 1000. Fig. 3: A photomicrograph of a section of thyroid gland of lithium treated rats (Group II) showing irregular shaped follicles with papillary infoldings projecting into the lumena (→). Extrafollicular colloid (*) is evident in the interfollicular spaces. H&E., Mic. Mag. X 100. 103 Fig. 6: A photomicrograph of a section of thyroid gland of lithium treated rats showing detached (→) and desquamated (►) follicular cells in the colloid of the follicles. H&E., Mic. Mag. X 200. Light and Electron Microscopic Study on the Effect of Lithium Carbonate on the Thyroid Gland Fig. 7: Higher magnification of the previous figure showing the detached follicular cells in the colloid (→). H&E., Mic. Mag. X 400. Fig. 8: A photomicrograph of a section of thyroid gland of lithium treated rats showing pinched apical parts of follicular cells (→) associated with apical vacuolation (►). H&E., Mic. Mag. X 1000. Fig. 9: A photomicrograph of a section of thyroid gland of lithium treated rats showing cellular infiltration in the interstitial tissue (*) and cytoplasmic vacuolation of follicular cells (→). H&E., Mic. Mag. X 1000. Fig. 10: A photomicrograph of a section of thyroid gland of lithium treated rats showing large eosinophilic cells in the interstitial tissue (→). Notice that the follicular cells have hyperchromatic nuclei. H&E., Mic. Mag X 1000. Fig. 11: A photomicrograph of a section of thyroid gland of lithium treated rats showing fibrosis of interstitial tissue (*). Mallory’s trichrome, Mic. Mag. X 400. Fig. 12: A photomicrograph of a section of thyroid gland of group III (Recovery Group) showing some thyroid follicles appeared similar to those of the control, while others still containing papillary infoldings (*). H&E., Mic. Mag. X 200. 104 Nafisa A. El-Bakary and Gehan M. Soliman Fig. 13: A photomicrograph of a section of thyroid gland of recovery group showing interstitial fibrosis (*). Mallory’s trichrome, Mic. Mag. X 400. Fig. 14: An electron micrograph of a section of thyroid gland of control group showing a part of thyroid follicle lined by cuboidal cells with rounded nuclei. The apical surfaces of these cells showed small microvilli (→) protruded into the follicular lumen (L) that contains colloid. Mic. Mag. X 3000. Fig. 15: An electron micrograph of a section of thyroid gland of lithium treated rats showing cellular debris in the follicular lumen (→). Mic. Mag. X 3000. 105 Fig. 16: Higher magnification of the previous figure showing cellular debris in the follicular lumen (→). Mic. Mag. X 6000. Fig. 17: An electron micrograph of a section of thyroid gland of lithium treated rats showing two adjacent follicular cells, one of them (F) showed dark cytoplasm and indistinct organelles as compared with the other cell (F1). Notice, microvilli (→) protruded into the lumen (L). Mic. Mag. X 6000. Fig. 18: An electron micrograph of a section of thyroid gland of recovery group showing the follicular cells appear more or less similar to control. Some cells contain dense bodies (→). Mic. Mag. X 3000. Light and Electron Microscopic Study on the Effect of Lithium Carbonate on the Thyroid Gland DISCUSSION of follicular disruption in lithium treated patients resembled those found in patients with silent thyroiditis which were considered to represent a destructive phase of chronic thyroiditis18. Such follicular destruction had also been reported in amiodarone induced hyperthyroidism19. This study showed that lithium treatment induced histological and ultrastructural changes in the thyroid gland of albino rats. Thyroid disturbances during lithium treatment had been reported. These commonly presented as goiter with or without hypothyroidism. Also some scientists stated that there were cases of hyperthyroidism among patients treated with lithium11,12. In addition, lithium associated thyroiditis and lithium associated autoimmune thyroiditis had been recorded6,13. In this study deeply eosinophilic cells were observed in the interstitial tissue in many specimens. Some investigators described deeply eosinophilic cells with granular cytoplasm called Hurthle cells in Hashimoto thyroiditis20. Cellular infiltration and interstitial fibrosis were observed in many specimens of this study. This appearance is consistent with that found in autoimmune thyroiditis20. Furthermore, some studies had reported a higher incidence of thyroid antibodies in patients treated with lithium compared with those not taking lithium21. In this research the thyroid glands of lithium treated animals were composed of large distended follicles with abundant colloid. Some of these follicles were lined with simple squamous epithelium, but many follicles were lined with tall columnar epithelium which showed hyperplasia and papillary infoldings projecting into the thyroid lumena. As regards to the ultrastructural findings, cellular debris in the follicular lumena, degenerated dark follicular cells in some follicles with indistinct organelles and detached apical parts of the cytoplasm of some follicular cells were observed in this study. These ultrastructural findings confirmed the light microscopic results and indicated that lithium could induce follicular cell damage and follicular disruption. The same results were reported by other investigators7. In this regard, some authors stated that lithium associated changes of the thyroid glands were similar to the changes seen in radiation –treated glands including the presence of nodular hyperplasia associated with increased cellularity and fibrosis14. The bizarreappearing nuclei of some follicular cells seen in this study were also recorded by other investigators who reported that in chronic lithium therapy the nuclei of follicular cells showed nucleomegaly, pleomorphism and hyperchromasia14. In this research, scalloping of the colloid edges was detected in many follicles in lithium treated animals. It was stated that the enlarged epithelial cells projecting into the lumena of the follicles actively resorb the colloid in the centers of the follicles, resulting in the scalloped appearance of the edges of the colloid15. In this investigation, the changes observed in the thyroid gland described above were no longer encountered after the drug withdrawal. However, few follicles still showed few papillary infoldings. Also; stromal fibrosis in some specimens was also observed. Ultrastructurally, the thyroid follicles appeared more or less similar to control except the presence of dense bodies in some follicular cells. In this regard, it was reported that some patients became euthyroid spontaneously with cessation of lithium treatment7. The mechanism of the effect of lithium on the thyroid gland is not fully understood. However, it had been reported that lithium is a monovalent cation that becomes concentrated in the thyroid gland16. It had been shown that lithium reduces iodine uptake into the gland, impairs coupling of iodotyrosines and interferes with the release of hormone from the gland7. CONCLUSION From this research, it could be suggested that lithium carbonate induced severe histological changes in the thyroid gland of albino rat and most of these changes were seen to be improved after withdrawal of the drug. REFERENCES In this study follicular disruption with release of colloid in the interfollicular spaces, detachment and desquamation of follicular cells and presence of these desquamated cells in the follicular colloid were common findings. Occasionally some thyroid follicles were filled with these desquamated cells. Such findings were similarly described by some investigators7 and others reported that lithium itself may directly injure thyroid follicular cells and cause thyroid follicular destruction17. They added that subsequent release of thyroglobulin increases the serum thyroid hormone concentration causing hyperthyroidism. On the other hand, it was stated that the histological features 1. 2. 3. 4. 106 Baldessarini RJ, Tondo L, Davis P, Pompili M, Goodwin FK and Hennen J. (2006): Decreased risk of suicides and attempts during long-term lithium treatment: A meta-analytic review. Bipolar Disord. Oct;8(5 Pt 2):625-639. Bertram GK. (2001): Basic and clinical pharmacology. 8th ed. Lange Medical Publications: Beirut, Lebanon. Markowitz GS, Radhakrishnan J, Kambham N, Valeri AM, Hines WH and D’Agati VD. (2000): Lithium nephrotoxicity: A progressive combined glomerular and tubulointerstitial nephropathy. J.Am.Soc.Nephrol. Aug;11(8):1439-1448. Herfindal ET and Gourley DR. (1996): Textbook of therapeutics: Nafisa A. El-Bakary and Gehan M. Soliman 5. 6. 7. 8. 9. Drugs and disease management. 6th ed. Lippincott Williams & Wilkins. Aliasgharpour M, Abbassi M, Shafaroodi H and Razi F. (2005): Subclinical hypothyroidism in lithium-treated psychiatric patients in Tehran, Islamic Republic of Iran. East. Mediterr. Health J. May; 11(3):329-333. Alastair JJW. (1995): Drug therapy. N. Engl. J. Med. ;333(25):1688-1694. Mizukami Y, Michigishi T, Nonomura A, Nakamura S, Noguchi M and Takazakura E. (1995): Histological features of the thyroid gland in a patient with lithium induced thyrotoxicosis. J. Clin. Pathol. Jun; 48(6):582-584. Paget GE and Barnes JM. (1964): Evaluation of drug activities. In: Lawrence DR, Bacharach AL, editors. Pharmacometrics: Academic Press, New York, NY. p. 30. Bancroft JD and Gamble M. (2002): Theory and practice of histological techniques. 5th ed. Churchill Livingstone. 14. 15. 16. 17. 18. 10. Bozzola JJ and Russell LD. (1999): Electron microscopy: Principles and techniques for biologists. Jones and Bartlett Publishers: Sudbury, MA. 11. Caykoylu A, Capoglu I, Unuvar N, Erdem F and Cetinkaya R. (2002): Thyroid abnormalities in lithium-treated patients with bipolar affective disorder. J. Int. Med. Res. Jan-Feb; 30(1):80-84. 12. Saikia UK and Saikia M. (2006): Drug-induced thyroid disorders. J.Indian Med.Assoc. Oct; 104(10):583, 585-7, 600. 13. Ozpoyraz N, Tamam L and Kulan E. (2002): Thyroid 19. 20. 21. 107 abnormalities in lithium-treated patients. Adv. Ther. Jul-Aug; 19(4):176-184. Wenig BM, Heffess CS and Adair CF. (1997): Atlas of endocrine pathology. 1st ed. WB Saunders Company. Cotran RS, Kumar V and Collins T. (1999): Robbins pathological basis of disease. WB Saunders Co.: Philadelphia, PA. McDermott MT, Burman KD, Hofeldt FD and Kidd GS. (1986): Lithium-associated thyrotoxicosis. Am. J. Med. Jun;80(6):1245-1248. Fauerholdt L and Vendsborg P. (1981): Thyroid gland morphology after lithium treatment. Acta Pathol. Microbiol. Scand.[A] Jul;89(4):339-341. Mizukami Y, Michigishi T, Nonomura A, Hashimoto T, Nakamura S, Tonami N and Takazakura E. (1993): Postpartum thyroiditis. A clinical, histologic and immunopathologic study of 15 cases. Am. J.Clin. Pathol. Sep; 100(3):200-205. Smyrk TC, Goellner JR, Brennan MD and Carney JA. (1987): Pathology of the thyroid in amiodarone-associated thyrotoxicosis. Am.J.Surg.Pathol. Mar;11(3):197-204. Shimizu M, Hirokawa M, Manabe T, Shimozuma K, Sonoo H and Harada T. (1997): Lithium associated autoimmune thyroiditis. J. Clin. Pathol. Feb; 50(2):172-174. Bocchetta A, Cocco F, Velluzzi F, Del Zompo M, Mariotti S and Loviselli A. (2007): Fifteen-year follow-up of thyroid function in lithium patients. J. Endocrinol. Invest. May; 30(5): 363-366. دراسة بالميكروسكوب الضوئي و االلكتروني لتأثير كربونات الليثيوم علي الغدة الدرقية في الجرذ األبيض البالغ نفيسة عبد الرحيم البقرى ،جيھان محمد سليمان قسم الھستولوجيا ،كلية الطب ،جامعة طنطا ملخص البحث ان كربونات الليثيوم ھي العالج المثالي لنوبات الجنون الحادة .و لذلك يوصف ھذا العقار في كثير من األحيان كعالج لمنع التغيرات المزاجية المفاجئة في مرضي الجنون االكتئابي ،و لقد وجد انه يسبب اضطرابات بالغدة الدرقية و لذا فان الھدف من ھذا البحث ھو دراسة ھستولوجية لتأثير كربونات الليثيوم علي الغدة الدرقية في الجرذ األبيض و دراسة امكانية النقاھة من تأثير ھذا العقار بعد ايقاف اعطاؤه. تم تقسيم ثالثون جرذا الي ثالث مجموعات متساوية ،المجموعة األولي ضابطة ,المجموعة الثانية تلقت 14.4مجم كربونات ليثيوم كجرعة لكل جرذ بالفم يوميا لمدة 6أسابيع ,أما المجموعة الثالثة فقد تلقت نفس جرعة كربونات الليثيوم بنفس الطريقة و لنفس المدة و لكن تم تركھا لمدة 6أسابيع أخري بعد ايقاف الدواء لدراسة امكانية النقاھة من ھذا الدواء بعد سحبه. و تم تجھيز عينات لفحصھا بالميكروسكوب الضوئي و االلكتروني. و قد أوضحت النتائج في المجموعة الثانية ظھور حويصالت الغدة الدرقية كبيرة و غير منتظمة مع وجود حلمات بارزة في تجاويف ھذه الحويصالت و وجود خاليا الحويصالت تالفة و منفصلة في السائل الھالمي الحويصلي .كما وجد تزايد ظاھري في عدد الخاليا الحويصلية مع عشوائية في األنوية .كما لوحظ وجود ارتشاح خلوي و ظھور خاليا كبيرة حمضية الصبغة و تليف في النسيج الخاللى فى بعض العينات ،أما دراسة التركيب الدقيق فقد وجدت نفايا خلوية في تجاويف الحويصالت و ظھور بعض الخاليا معتمة ذات أنوية داكنه و صغيرة مع عدم وضوح العضيات ،و في المجموعة الثالثة فان كل ھذه التغيرات لم تكن ملحوظة بدرجة أو بأخري. نستنتج من ھذا البحث أن عقار كربونات الليثيوم يؤدي الي تغيرات جسيمة في تركيب الغدة الدرقية في الجرذ األبيض و لقد تحسنت تلك التغيرات بعد سحب ھذا الدواء .و لذلك فانه ينصح بعدم استخدام ھذا العقار اال في حاالت مرضية معينة و تحت أشراف طبي مباشر. 108