Eur J Anat, 13 (2): 49-66 (2009)

Calcium folinate diminishes the teratogenic effects of all-trans retinoic acid in the developing craniofacial region and neural tube of the rat

Richardson L.J., Emmanouil-Nikoloussi E.-N., Moxham B.J.

Cardiff School of Biosciences, Cardiff University, Cardiff CF10 3AX, United Kingdom; Laboratory of Histology-Embryology and Anthropology, Faculty of Medicine, Aristotle University of Thessaloni-ki, Thessaloniki 54124, Greece

ABSTRACT This study tests the hypothesis that calcium folinate diminishes, or ameliorates, the teratogenic effects of all-trans retinoic acid during craniofacial and neural tube development. Four experimental groups were used; two were treated with three doses of 30mg/k.b.w all-trans retinoic acid (on gestational days 9, 10, and 11), with one of these groups having additional doses of calcium folinate (5mg/k.b.w.). The other two groups were given higher doses of all-trans retinoic acid (50mg/k.b.w), with again one of these groups having additional doses of calcium folinate (5mg/k.b.w.). Retinoic acid was administered by gastric intubation and calcium folinate by peritoneal injection. Two further control groups were used where the pregnant rats were exposed to neither all-trans retinoic acid nor calcium folinate. All rats were sacrificed on gestational day 18. Standard histological techniques were employed to assess the extent of abnormal development of the craniofacial region (including the palate) and the brain. The fetuses treated with all-trans retinoic acid alone showed varying degrees of neural tube defects (including excencephaly, myelomeningocele and spina bifida), eye malformations and clefting of the face and palate. However, fetuses treated with calcium folinate showed no neural tube and eye defects and only occasionally minor clefting in the presumptive hard palate. In addition, although many fetal absorptions and teratomas were seen within the litters of rats treated only with all-trans retinoic acid, there were no absorptions (and few teratomas) seen with calcium folinate supplements. The findings support our initial hypothesis concerning the beneficial effects of calcium folinate on craniofacial development.

Keywords: folinate calcium, retinoic acid, animal experiment, animal model, animal tissue, article, cleft lip, cleft palate, controlled study, craniofacial development, craniofacial morphology, drug activity, eye malformation, neural tube, neural tube defect, nonhuman, rat, teratogenesis