Effects of low‐dose melamine exposure during pregnancy on maternal and fetal kidneys in rats

• Published in: Environmental toxicology 2018-03, Vol.33 (3), p.370-380
• Main Authors: Chu, Ching Yan, Fung, Kwok Pui, Wang, Chi Chiu
• Format: Article
• Language: English
• Subjects: Animal embryos; Animals; Contamination; Crystals; development; Edema; Embryonic Development; Embryos; Epithelium; Exposure; Female; Fetus; Fetuses; Gastrulation; Gastrulation - drug effects; Health problems; Hyperplasia; Implantation; Intrauterine exposure; kidney; Kidney - drug effects; Kidney - embryology; Kidney - growth & development; Kidney - pathology; Kidneys; Low level; maternal; Maternal Exposure - adverse effects; Maternal-Fetal Exchange; Melamine; Neonates; nephrotoxicity; Organogenesis; Organogenesis - drug effects; Pregnancy; prenatal; Prenatal Exposure Delayed Effects - pathology; Rats; Rats, Sprague-Dawley; Renal tubules; Rodents; Triazines - toxicity
• ISSN: 1520-4081; 1522-7278
• DOI: 10.1002/tox.22525

Despite the previous reports on melamine contamination in high concentrations some years ago, there were not many studies on low‐level exposure in daily life, particularly in pregnancy. We investigated the effect of low‐dose melamine on the kidneys of the pregnant rats and their developing embryos/fetuses during various gestational stages namely implantation, gastrulation, organogenesis, maturation and whole pregnancy. Our results showed that the repeated low level of melamine (12.5, 25, and 50 mg/kg bw/d) during pregnancy did not cause obstruction of renal tubules although more precipitating crystals were found in the early gestational periods. Simple hyperplasia in the maternal tubules and pelvic epithelium were more prominent after exposed to melamine during the whole gestational period. Neonatal kidneys significantly suffered more from congestion in glomeruli and interstitium, dilated tubules and interstitial edema after melamine administration to the mother in the late and the whole gestational periods. A trend of advance of glomerular development in fetuses was also observed. We conclude that in utero exposure of low‐level melamine could post a risk on the kidneys of the pregnant mother as well as the developing fetuses, which may further increase the possibility of other health problems later in life.