Muscle Metabolism in the Presence of an Active and Inactive Nervous System

Abstract

Perfusion of the isolated hind-limb of rats according to Ruderman (1971) was used to study the effect of survival of the animal during perfusion on various metabolic parameters. Considerable differences were found between rats killed before perfusion and live rats. In living animals glycerol production and lactate production are higher than in dead animals. Glucose consumption is higher in the latter. The main cause of these differences seems to be the influence of an active sympathetic nervous system in living animals, which is inactivated in a dead animal. This conclusion is corroborated by the results of experiments done in animals treated with propanolol. Lactate production is probably not under sole control of the sympathetic nervous system. The higher glucose uptake and lower lactate production found by Strohfeld (1973), as compared with the results of Ruderman (1971), is not necessarily only a reflection of the feeding state of the animal but may also be the expression of a difference in the activity of the sympathetic nervous system. Consequently, in the investigation of muscle metabolism in an isolated hind-quarter the activity of the sympathetic nervous system should be taken into account in the interpretation of the results.

Key words

Skeletal Muscle - Hind Limb Perfusion - Sympathetic Nervous System - Propanolol