Variation of ascorbic acid content in the different tissues of the frog Rana tigrina as a function of season.

Ascorbic acid concentrations of the liver, thigh, and cardiac muscles, ventral and dorsal skin, as well as muscles of the frog Rana tigrina were higher during summer and lower in winter. Ascorbate concentration also showed another high peak in February. The cardiac ascorbate showed minimal seasonal fluctuations.