Vitamin D metabolism impairment in the rat's offspring following maternal exposure to 137cesium.
Arch Toxicol. 2009 Apr;83(4):357-62. Epub 2008 Sep 17. PMID: 18797846
Radiological Protection and Human Health Division, Radiobiology and Epidemiology Department, Laboratory of Experimental Toxicology, Institute for Radiological Protection and Nuclear Safety, BP n(o) 17, 92262 Fontenay-aux-Roses Cedex, France.
Previous works clearly showed that chronic contamination by 137cesium alters vitamin D metabolism. Since children are known to be a high-risk group for vitamin D metabolism disorders, effects of 137Cs on vitamin D biosynthetic pathway were investigated in newborn rats. The experiments were performed in 21-day-old male offspring of dams exposed to 137Cs in their drinking water at a dose of 6,500 Bq/l (150 Bq/rat/day) during the lactation period. Significant modifications of blood calcium (-7%, P<0.05), phosphate (+80%, P<0.01) and osteocalcin (-25%, P<0.05) levels were observed in contaminated offspring, associated with an increase of blood vitamin D3 (+25%, P<0.01). Besides, decreased expression levels of cyp2r1 and cyp27b1 (-26 and -39%, respectively, P<0.01) were measured in liver and kidney suggesting a physiological adaptation in response to the rise in vitamin D level. Expressions of vdr, ecac1, cabp-d28k, ecac2 and cabp-9k involved in renal and intestinal calcium transport were unaffected. Altogether, these data show that early exposure to post-accidental doses of 137Cs induces the alteration of vitamin D metabolism, associated with a dysregulation of mineral homeostasis.