Anaerobic Glycogenolysis in the Muscles of Rana Pipiens Living at Low Temperatures

Abstract

When attempts failed (16) to produce glycolytically active extracts from the muscles of winter frogs stored at 4°C., and when lactate production at 0°C. by their gastrocnemii could not be detected (12, 17) we began to study the glycogen metabolism during fatigue of the muscles from such frogs. Previous workers have shown alterations in the carbohydrate metabofism of frog muscles with low glycogen contents, and also seasonal variations in the carbohydrate metabolism of frogs.If sartorii and gastrocnemii of R. temporaria and R. esculenta have low carbohydrate reserves, they can contract aerobically on sources of energy only partly carbohydrate (30, 10). When mammalian muscles are rendered low in glycogen by the use of insulin or thyroid, rigor mortis in them is not accompanied by glycogenolysis or by lactate production (15). Olmsted and his colleagues (31, 32) were the first to use insulin convulsions for rendering muscles of R. pipiens and R. catesbiana nearly free of glycogen; muscles so prepared contracted anaerobically without glycogenolysis or lactate production. Ochoa (30) and Gemmill (10) extended these observations to R. temporaria and R. esculenta.It has been known for a long time that there is marked seasonal variation in the carbohydrate metabolism of frogs' tissues. Schiff (36) in 1859 observed that there is little postmortem glycogenolysis at 23°C. by the livers of frogs caught in the winter. Grode and Lesser (13) set up uninjured livers and muscles of frogs for 4 hours at 22-23°C. in Ringer's solution under aerobic conditions. In November and December such preparations showed only very slight decreases in glycogen, despite initial concentrations of 0.75 to 1.24 per cent. At other times of the year, decreases of 15-20 per cent of the initial value were observed. If in November or December the organs were cut or severely injured, marked glycogenolysis took place. Lesser (21) analyzed whole frogs for glycogen. In the summer, anaerobiosis of 2 hours led to marked glycogenolysis. A subsequent 24 hours of aerobiosis led to restitution of most of the glycogen. In November and December, anaerobiosis of 2 hours did not produce glycogenolysis.

Anuran activity energetics

“…The oxygen tension in the mud is very low (Hutchison ~al, 1964;Poczopko,_ 1959). Both the resting oxygen consumption (Fromm and Johnson, 1955) and tissue metabolism (Barger and Johnson, 1941;Rose and Orotman, 1967) Ferhst's (1977) theory for the evolution of maximum rate through maximizing Km.…”