The skeletal developmental toxicity of chlormequat chloride and its underlying mechanisms. (15th April 2017)

• Record Type: Journal Article
• Authors: Huang, Dan; Wu, Shuang; Hou, Xiaohong; Jia, Lixia; Meng, Qinghe; Chu, Hongqian; Jiang, Jianjun; Shang, Lanqin; Hao, Weidong
• Is Part Of: Toxicology. Volume 381(2017)
• Page Start: 1
• Page End: 9
• Publication Date: 2017-04-15
• Subjects: Chlormequat chloride -- Skeletal development -- Growth hormone -- Insulin-like growth factor-I; Toxicology -- Periodicals; Chemicals -- Physiological effect -- Periodicals; 615.9005
• DOI: 10.1016/j.tox.2017.02.003
• Languages: English
• ISSNs: 0300-483X

Abstract

Abstract: Chlormequat Chloride (CCC), a widely used plant growth regulator, could decrease body weight in animals; however, the mechanism has not been well studied. This study was designed to evaluate the skeletal development toxicity of CCC on pubertal male Sprague-Dawley (SD) rats and to investigate whether CCC impacts the development of chondrocyte, osteoblast and osteoclast through growth hormone (GH) and insulin like growth factor 1 (IGF-I). Rats from 23 to 70 on postnatal days were exposed to CCC daily by gavage at doses of 0, 75, 150, and 300 mg/kg bw/d. The results showed that the size of femurs and tibias, bone mineral density and biomechanical parameters were significantly decreased in the 300 mg/kg bw/d group compared with the control group. The concentration of osteocalcin (OCN) and C-terminal telopeptide of type I collagen (CTX-I) in blood in the 150 mg/kg bw/d group was also changed. The mRNA expression ratio of the receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) in 150 and 300 mg/kg bw/d group was increased. Histological analysis of proximal and distal epiphyseal plates of the right femurs showed that both the proliferative zone and hypertrophic zone narrowed in CCC-treated groups. The concentration of IGF-I in blood was reduced with an increase in exposure doses of CCC. The mRNA expression of growth hormone receptor (GHR) in tibia was decreased in the CCC-treated group. The results indicated that CCC might indirectly impact the formation and activation of chondrocytes, osteoblasts and osteoclasts because of the decline of GHR and IGF-I, leading to skeletal development damage.