Chronic Iodine Intake Excess Damages the Structure of Articular Cartilage and Epiphyseal Growth Plate

• Published in: Biological trace element research Vol. 202; no. 9; pp. 4078 - 4086
• Main Authors: Zhang, Ying, Zhao, Xin, Shan, Le, Liu, Miao, Zhang, Zixuan, Wang, Zeji, Zhang, Xinbao, Meng, Haohao, Song, Yan, Zhang, Wanqi, Sang, Zhongna
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.09.2024; Springer Nature B.V
• Subjects: Animals; Arsenic; Biochemistry; Biomedical and Life Sciences; Biotechnology; Cartilage; Cartilage (articular); Cartilage diseases; Cartilage, Articular - drug effects; Cartilage, Articular - metabolism; Cartilage, Articular - pathology; Cerium; Chemiluminescence; Chondrocytes; Collagen; Collagen (type II); Collagen (type X); Collagenase 3; Epiphyseal growth plate; Fibroblast growth factor receptor 1; Gene expression; Growth factors; Growth plate; Growth Plate - drug effects; Growth Plate - metabolism; Growth Plate - pathology; Hypothyroidism; Iodine; Iodine - urine; Life Sciences; Male; Matrix metalloproteinase; Matrix Metalloproteinase 13 - genetics; Matrix Metalloproteinase 13 - metabolism; Matrix metalloproteinases; Metalloproteinase; Nucleotide sequence; Nutrition; Oncology; Osteoarthritis; Overdose; PCR; Rats; Rats, Wistar; Spectrophotometry; Thickness; Thyroid; Growth plate; Iodine excess; Rat; Articular cartilage; Thyroid function
• ISSN: 0163-4984; 1559-0720; 1559-0720
• DOI: 10.1007/s12011-023-03985-6

This study aimed to explore the influence of excess iodine on the articular cartilage and epiphyseal growth plate in rats. Wistar rats ( n  = 200) were randomly divided into five groups with 40 rats in each: normal iodine (NI), 5-fold high iodine group (5HI), 10-fold high iodine group (10HI), 50-fold high iodine group (50HI), and 100-fold high iodine group (100HI). The rats were executed in 6 and 12 months. 24-h urinary iodine concentration (UIC) was monitored by arsenic-cerium catalytic spectrophotometry. The chemiluminescence method was used to determine the thyroid function. The pathological changes in the epiphyseal plate, articular cartilage, and thickness of the epiphyseal plate were observed. The mRNA expression of collagen II (ColII), collagen X, matrix metalloproteinase-13 (MMP-13), and fibroblast growth factor receptor 1 in articular chondrocytes was detected by RT-PCR. 24-h UIC increased as iodine intake increased. In the 12th month, there was a significant increase in serum sTSH and a decrease in serum FT 4 in HI groups, compared to the NI group. There was a decrease in the number of proliferating cells in the epiphyseal plate and an increase in the number of mast cell layers. The chondrocytes appeared disorganized, and the tidal lines were disturbed or even broken. Growth plate thickness decreased with increasing iodine intake. Compared with the NI group, ColII and MMP-13 mRNA expression in chondrocytes in all HI groups significantly increased. Chronic iodine overdose increases the risk of hypothyroidism. Chronic iodine overdose leads to abnormal morphology of epiphyseal growth plates and articular cartilage, increasing the risk of osteoarthritis.