The contents of adenine nucleotides, phosphagens and some glycolytic intermediates in resting muscles from vertebrates and invertebrates

Abstract

The lowest contents of ATP and the lowest ATP/AMP concentration ratios are observed in the molluscan muscles that have very low rates of energy expenditure during contraction. The highest contents of ATP are observed in the extremely aerobic insect flight muscle and the extremely anaerobic pectoral muscle of the pheasant and domestic fowl. In general, the lowest ATP/AMP concentration ratios are observed for muscle in which the variation in the rate of energy utilization is small (e.g. some molluscan muscles, heart muscle); the highest ratios are observed in muscles in which this variation is large (lobster abdominal muscle, pheasant pectoral muscle, some insect flight muscles). This finding is consistent with the proposed role of AMP and the adenylate kinase reaction in the regulation of glycolysis. However, in the flight muscle of the honey-bee the ATP/AMP ratio is very low, so that glycolysis may be regulated by factors other than the variation in AMP concentration. The variation in the contents of arginine phosphate in muscle from the invertebrates is much larger than the variation in creatine phosphate in muscle from the vertebrates. The contents of hexose monophosphates and pyruvate are, in general, higher in the muscles of vertebrates than in those of the invertebrates. The contents of phosphoenolpyruvate are similar in all the muscles investigated, except for the honey-bee in which it is about 4-10-fold higher. The mass-action ratios for the reactions catalysed by phosphoglucoisomerase and adenylate kinase are very similar to the equilibrium constants for these reactions. Further, the variation in the mass-action ratios between muscles is small. It is concluded that these enzymes catalyse reactions close to equilibrium. However, the mass-action ratios for the reactions catalysed by phosphofructokinase and pyruvate kinase are much smaller than the equilibrium constants. The variation in the ratios between different muscles is large. It is concluded that these enzymes catalyse nonequilibrium reactions. Since the variation in the mass-action ratios for the reactions catalysed by the phosphagen kinases (i.e. creatine and arginine phosphokinases) is small, it is suggested that these reactions are close to equilibrium.

Metabolic performance of the squid Lolliguncula brevis (Cephalopoda) during hypoxia: an analysis of the critical PO2

“…containing 160 mmol?l potassium fluoride and 1 mmol?l nitrilotriacetic acid. The remaining tissue powder was extracted in perchloric acid following the procedure of Beis and Newsholme (1975), and modified according to Pette and Reichmann (1982). The adenylates ATP, ADP, AMP and succinate and glycerol-3-phosphate were assayed according to Bergmeyer et al (1983Bergmeyer et al ( -1986, inorganic phosphate was estimated according to Portner (1990), and phospho-L-arginine, arginine and octopine quantities were determined following the procedure of Grieshaber et al (1978).…”

Osmotic surveillance mediates rapid wound closure through nucleotide release

“…Nucleoside triphosphates (NTPs), such as ATP, are present in the cytoplasm of all cells at high concentrations ([ATP] 5 mM; Beis and Newsholme, 1975). Vesicular NTP concentrations can be an order of magnitude higher ([ATP] 90 mM; Johnson, 1988).…”

The influence of defined ante-mortem stressors on the early post-mortem biochemical processes in the abdominal muscle of the Norway lobster,Nephrops norvegicus(Linnaeus, 1758)

“…during escape swimming, comprise mainly fast-type fibres that are biochemically equipped for rapid burst activity (Neil et al 1993). These fast-type crustacean muscles are generally similar in both structure and metabolic properties to vertebrate fast-type muscles (Hoyle 1969;Beis & Newsholme 1975;Hooper & Thuma 2005;Gornik et al 2008). To meet the energy demands of tail flipping and in a variety of other physiological circumstances, such fast-type muscles utilize anaerobic energy pathways (mainly glycolytic fermentation) (Ellington 1983).…”