title: Effect of different doses of monosodium glutamate on the thyroid follicular cells of adult male albino rats: a histological study.
abstract: Monosodium glutamate (MSG) is a major flavor enhancer used as a food additive. The present study investigates the effects of different doses of MSG on the morphometric and histological changes of the thyroid gland. 28 male albino rats were used. The rats were divided into four groups: group I control, group II, III and IV treated with MSG (0.25 g/kg, 3 g/kg, 6 g/kg daily for one month) respectively. The thyroid glands were dissected out and prepared for light and electron microscopic examination. Light microscopic examination of thyroid gland of group II revealed increase in follicular epithelial height. Groups III & IV showed decrease in the follicular diameter and irregularity in the shape of some follicles with discontinuity of basement membrane. Follicular hyperplasia was detected in some follicles with appearance of multiple pyknotic nuclei in follicular and interfollicular cells and multiple exfoliated cells in the colloid. In addition, areas of loss of follicular pattern were appeared in group IV. Immunohistochemical examination of BCL2 immunoexpression of the thyroid glands of groups III & IV reveals weak positive reaction in the follicular cells cytoplasm. Ultrathin sections examination of groups III & IV revealed follicular cells with irregular hyperchromatic nuclei, marked dilatation of rER and increased lysosomes with areas of short or lost apical microvilli. In addition, vacuolation of mitochondria was detected in group IV. The results displayed that MSG even at low doses is capable of producing alterations in the body weights and thyroid tissue function and histology.
authors.affiliation: Department of Histology, Faculty of Medicine, Mansoura University Egypt.
authors.forename: Hanaa A
authors.initials: HA
authors.lastname: Khalaf
authors.affiliation: Department of Histology, Faculty of Medicine, Mansoura UniversityEgypt; Departement of Anatomy, Taif UniversityKSA.
authors.forename: Eetmad A
authors.initials: EA
authors.lastname: Arafat
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000187:drug effects / Q000648:ultrastructure; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D005421:Flavoring Agents / Q000633:toxicity*; D006965:Hyperplasia; D008247:Lysosomes / Q000187:drug effects / Q000648:ultrastructure; D008297:Male; D009929:Organ Size; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D051381:Rats; D018570:Risk Assessment; D012970:Sodium Glutamate / Q000633:toxicity*; D013961:Thyroid Gland / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D013997:Time Factors
chemical_list: D005421:Flavoring Agents; D019253:Proto-Oncogene Proteins c-bcl-2; D012970:Sodium Glutamate
keywords: Monosodium glutamate; histological study; thyroid gland