Abstract:

To illustrate dynamics of secretion and the peptides patterns of Rana dybowskii, the crude skin secretions were collected at different time when their secretions were released with a mild electrical stimulation. The results showed that the restoring amount of skin secretions increased in a characteristic sigmoid curve during 0-21 days after an electrical stimulation. The HPLC showed that the skin secretions collected at different time had the identical components, however the components restored asynchronously. Two quickly-restored components peaks were tested for their antibacterial activity against Escherichia coli ATCC25922 and Staphylococcus aureus ATCC25923 and showed strong antibacterial activity. The two components were identified by ESI-MS/MS and their amino acid sequences were determined. The results indicated that the recovery rates of skin secretion components in R. dybowskii were asynchronous and the antimicrobial peptides had precedence over other peptides. The immune defense strategy would ensure the survival of frogs in a complex environment.

Key words: Rana dybowskii, skin secretion, active peptide, ambient pressure, adaptability