Effects of hydrocortisone on hind limb regeneration in the tadpoles of toad, Bufo andersonii

Hind limb regeneration was studied in the tadpoles of toad, Bufo andersonii of developmental stages IX, X and XI according to the normal table of Taylor and Kollros(1) for Rana pipiens. Following amputation through thigh, shank and ankle levels, the control were reared in water and the experimental groups in 5, 7.5, 10, 15, 20, 30, 40, and 50 mu g/ml concentrations of hydrocortisone. Legs regenerated at various levels showed a decline of regenerative capacity at thigh, shank and ankle levels. It is manifested in production of progressively increasing number of oligodactylous and defective regenerates. Frequency of regenerates depends on the levels of amputation, stage of development of tadpoles and on the concentrations of hydrocortisone in the medium. High concentrations of the hormone are inhibitory and destructive. Hydrocortisone treatment improved the quality of regenerates but the subsequent processes of differentiation and growth are inhibited.