Seasonal fluctuations of adenylic compounds in frog gastrocnemius

Summary As a result of 2 year observations a fact of seasonal fluctuations in the adenine system components was revealed in the gastrocnemius ofRana temporaria. The ATP content, minimal in February–April (about 150 mg%), increased in July by 60%. The ADP content in the muscles was the highest in December–January (over 40 mg%), and the lowest in July (about 20 mg%). No AMP was found to occur in the muscles. Changes in the total of the adenine system component were close to those in the ATP content.The described variations correspond to the cycle ofRana temporaria activity. The minimal and the maximal ATP content and of the total of the adenine system components coincided with the turning points of the yearly cycle—the beginning and end of hybernation.Presented by Active Member AMN SSSR S. E. Severiny Translated from Byulleten' Éksperimetal'noi Biologii i Meditsiny, Vol. 59, No. 1, pp. 60–62, January, 1965