The response to ether anesthesia and to electric stimulation of glycolytic metabolites in a red and a white muscle of the rat

Summary Since ether anesthesia lowered ATP by 25% in red, but not in white muscle, and only when the spinal neurones were intact, we suggested that small or intermediate muscle units were activated under ether anesthesia 8].In order to prove this postulate, some glycolytic metabolites, known to rise under muscular activation, are studied in the white musculus adductor magnus and in the red musculus pyramidalis of the rat: glucose-1-phosphate, glucose-6-phosphate, fructose-6-phosphate, fructose-1-6-diphosphate, -glycerophosphate, lactate, pyruvate, and dihydroxyacetone phosphate.The conditions compared are: Inactin (5-ethyl-5(methyl-propyl)-2-thiobarbituric acid)-anesthesia, diethyl ether anesthesia, and tetanic contraction under Inactin anesthesia.The histological assay with Sudan-black B staining shows 34.2±7.3% dark fibers in m. pyramidalis and 0.2±4.8% dark fibers in m. adductor magnus.Glucose-1-phosphate, fructose-1-6-diphosphate, and -glycerophosphate are elevated under ether anesthesia in both muscles versus Inactin anesthesia by 100–200%.Lactate in both muscles and pyruvate in the red muscle are slightly elevated under ether (by 40%) versus Inactin anesthesia.Under tetanic contraction the metabolites studied rise considerably in both muscles.As glycogen is lowered in rat muscle under ether 9], the present results suggest an activation of glycogen phosphorylase and of phosphofructokinase in both the red and the white muscle under ether anesthesia, which results in augmented glycolysis.The comparatively small increment of pyruvate and lactate in the presence of a high increment of -glycerophosphate under ether anesthesia is considered to indicate an asynchronous activation of fibers with unimpaired circulation and oxidative metabolism.