Effect of Prenatal Administration of Retinoic Acid on Developing Spinal Cord of Albino Rats

Background Vitamin A and its derivatives (Retinoids) are essential for both normal embryonic development and maintenance of differentiation.Retinoids is a well-known teratogen when administered to embryos Aim to investigate the structural changes induced by prenatal administration of vitamin A on the developing spinal cord of albino rats. Material and methods forty pregnant albino rats were exposed to variable doses of vitamin A (retinylpalmitate) on gd 10.The pregnant albino rats were divided into three groups: Group I (control): rats received sesame oil by oral gavagedaily, till date of delivery. Group II (minimum therapeutic dose): rats were given retinylpalmitate 50 mg/kg daily. Group III (maximum therapeutic dose): rats were givenretinylpalmitate 100 mg/kg daily. The viable offspring of all groups were evaluated for changes in developing spinal cord at PND10. At the end of the experiment, rats offspring were sacrificed, the spinal cord were dissected out, and subjected to histological examination followed by computer image analysis. Results PDN10 neonates of mothers received minimum dose of vitamin A (subgroup II) revealed few immature irregular dorsal horn neurons with relatively decreased cellular density in anterior horn neurons. Meanwhile, the PDN10 neonates of mothers received daily maximum therapeutic dose of vitamin A (subgroup III) exhibited dark,pyknotic nucleiand packed dorsal horn cells while anterior horn cells were shrunkenandkaryoliticnuclei. Conclusion minimum and maximum doses of vitamin A in pregnant rats attributed to morphological changes in spinal cord of their young neonates and in long term follow up which was more obvious in maximum dose than low intake. Therefore, it might be assumed that neither minimum nor maximum dose could be used as a safe drug for their serious side effects on spinal cord morphology and consequently its functions.