Teratological Effects of Retinoids on Skeletal Elements of Swiss Albino Mice

The specific branch o developmental biology which deals with abnormalities caused as a result of failure of normal pattern of development is referred as teratogenesis. Retinoids are essential for spermatogenesis, oogenesis, placental development, foetal morphogenesis and growth. The role of vitamin A in vision is well known. Active derivative of vitamin A (Retinoids) play an important and multiple role in Mammalian development and homeostasis (Sapin, et.al. 1997, Dup et al 1997). These essential dietary compounds are needed in very small quantities, they are not synthesized by the animals and are obtained from external sources in the form of β carotene (C40H56). In cells of intestine β carotene is converted into vitamin A alcohol and is transported by blood to liver where it is esterfied and stored as vitamin A palmitate. RA is not stored in liver but is derived from retinal and it is biologically the most potent form of vitamin A. Vitamins are organic compounds which are devided into 2 categories i Fat soluble (A,D,E,K) and ii water soluble (B and C). Vitamin A belongs to fat soluble category of vitamins. A fat soluble substance essential for life was first discovered in egg yolk in 1909 by Stepp (Pawson, 1981; Robert and Sporn, 1984). It was confirmed by Mc Collum Devis in 1913 when he found a compound with similar biological activity in butter fats, egg yolk and cod liver oil and was named fat soluble vitamin A. The development of an organism is a complex process of embryogenesis involving cell proliferation, differentiation, migration and organogenesis. Many agents interfering the development process can cause malformations in the embryo. The study of these congenital abnormalities is called teratology and agents which are responsible for causing these malformations are called teratogens. Susceptibility to teratogens depends on the genotype of the organism, including species as well as strain differences. Etienne Geoffrey Saint Hilaire and his son in 1820 started experiments on chick embryo by disturbing its environment in different ways at different embryonic stages. They found some anomalies like Trioncephally, atrophy of eyes and spina bifida in his experiments (Tuli, 1968). In 1877 Dareste reported found some anomalies like Trioncephally, atrophy of eyes and spina bifida in his Experiments (Tuli, 1968). 4mg RA severely damaged skin on later stage ie 11th and 14th day gestation period, of development, shows disruption and folds of skin look like over verying skin flaps. In the present paper effects of different doses of vitamin A on Skeletal elements on different development stages of swiss albino mice are studied.