Toxicological effects of Tris (1,3‐dichloro‐2‐propyl) phosphate exposure in adult male rats differ depending on the history of exposure in the neonatal period

• Published in: Journal of applied toxicology 2022-09, Vol.42 (9), p.1503-1509
• Main Authors: Akimoto, Takahiro, Kobayashi, Shohei, Nakayama, Airi, Isobe, Anna, Abe, Koudai, Hatakeyama, Taichi, Ohta, Ryo, Yanagisawa, Rie, Koike, Eiko, Suzuki, Noriyuki, Kawaguchi, Maiko
• Format: Article
• Language: English
• Subjects: Adrenal glands; adrenal grands; Adults; Animals; Chemicals; Exposure; exposure history; flame retardant; Histopathology; Iron; Males; Neonates; Organ weight; Pediatrics; rat; serum iron; Sesame oil; Sesamum; TDCIPP; Toxicity; Toxicology; Toxins; UIBC; Vegetable oils
• ISSN: 0260-437X; 1099-1263
• DOI: 10.1002/jat.4316

There is increasing concern about multiple high concentration exposure to toxins in disaster and emergency situations. However, conventional toxicology testing methods may not adequately address these situations. Thus, we assessed whether the toxic effects of exposure in the adulthood differ depending on the presence or absence of neonatal exposure to Tris (1,3‐dichloro‐2‐propyl) phosphate (TDCIPP) in male rats to investigate the effects of exposure history of chemicals. In the neonatal stage [postnatal days (PNDs) 1–7], animals were treated with either sesame oil (5 ml/kg/day) as a control or TDCIPP (250 mg/kg/day) dissolved in sesame oil. In adulthood (PND 101–107), animals were treated with either sesame oil (5 ml/kg/day) or TDCIPP (650 mg/kg/day). One day after the final administration, dissection was performed, and body and organ weight, hematology, blood biochemistry, and histopathology were examined. The results demonstrated that the toxic effects of TDCIPP exposure in adulthood on adrenal gland size, serum iron content, and unsaturated iron binding capacity were enhanced by TDCIPP exposure in the neonatal stage. From these findings, it was indicated that the toxic effects of TDCIPP exposure in the adult stage are affected by pediatric exposure. These results suggest that the toxic effects of high‐dose and long‐term unsteady exposure to chemicals in large‐scale disasters may change based on the exposure history of chemicals. Conventional toxicology tests may not address intermittent disasters. We assessed the toxic effects of transient high concentration toxin exposure to Tris (1,3‐dichloro‐2‐propyl) phosphate (TDCIPP) in the neonatal and adult stages. Rats exposed to TDCIPP in both stages exhibited significantly higher adrenal weight, lower serum iron levels, and higher unsaturated iron binding capacity than rats treated with TDCIPP exposure only in adulthood, indicating that the effects of adult toxin exposure are affected by neonatal exposure.