Effect of prednisolone on the development of amphibian larvae and the antagonism of litoralon and prednisolone

Abstract Larvae of Rana arvalis Wolterstorffi of developmental stage 26 ( Terentiev, 1950 ; stage 26/IV, Taylor and Kollros, 1946 ) were placed for 2 hr daily in aqueous solution of 10 μg/ml prednisolone succinate sodium (Di-Adreson-F-aquosum, Organon; prednisolone) or of 10 μg/ml prednisolone + 0.5 μg litoralon (γ- l -glutamyl-taurine; glutaurine), a biologically active substance isolated from the bovine parathyroid and produced synthetically. Body length and development of the larvae were studied. Prednisolone was found to enhance the development of Rana arvalis Wolterstorffi larvae and this effect was antagonized by litoralon. Correlation of this observation with our earlier experimental results implied the possibility that the glucocorticoid and thyroid hormones in some respects antagonize the effects of litoralon and vitamin A.