Oscillatory behavior of glycolysis is observed when cell-free extracts of rat skeletal muscle are provided with glucose. Experimental studies and theoretical treatments have indicated that under certain conditions such oscillatory behavior can maintain a higher [ATP]/[ADP] ratio than corresponding steady state or steady flux behavior. This project will examine the effects of fructose 2,6-bisphosphate, citrate creatine phosphate and orthophosphate, in comparison with roles suggested by models of the oscillations. The importance of the level of glyceraldehyde 3-phosphate dehydrogenase activity in determining oscillatory or steady state behavior will be tested, as will the possibilities for interacting control of phosphofructokinase and phosphorylase with glycogen as carbon source. Spectrophotometric and fluorometric techniques will be used for continuously monitoring the system, and frequent samples will be assayed for all the glycolytic intermediates in order to follow in detail the changing pattern of the glycolytic flux under different conditions. The objective of this project is to clarify the role of specific control properties of the individual enzymes in determining the behavior of the system as a whole and to relate the complex behavior to appropriate metabolic contexts. A second objective is to obtain evidence for the occurrence of such oscillations in muscle in vivo, using very thin intact muscle and also cultured chick myotubes and rat aortic smooth muscle cells; spectrophotometric and fluorometric techniques will be used, together with metabolite assays where possible.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK031559-06
Application #
3230165
Study Section
Physiological Chemistry Study Section (PC)
Project Start
1983-04-01
Project End
1991-06-30
Budget Start
1988-06-01
Budget End
1991-06-30
Support Year
6
Fiscal Year
1988
Total Cost
Indirect Cost
Name
Boston University
Department
Type
Schools of Medicine
DUNS #
604483045
City
Boston
State
MA
Country
United States
Zip Code
02118
Cunningham, Barbara A; Richard, Ann-Marie T; Dillon, Joseph S et al. (2003) Glucagon-like peptide 1 and fatty acids amplify pulsatile insulin secretion from perifused rat islets. Biochem J 369:173-8
Civelek, V N; Deeney, J T; Fusonie, G E et al. (1997) Oscillations in oxygen consumption by permeabilized clonal pancreatic beta-cells (HIT) incubated in an oscillatory glycolyzing muscle extract: roles of free Ca2+, substrates, and the ATP/ADP ratio. Diabetes 46:51-6
Civelek, V N; Deeney, J T; Kubik, K et al. (1996) Temporal sequence of metabolic and ionic events in glucose-stimulated clonal pancreatic beta-cells (HIT). Biochem J 315 ( Pt 3):1015-9
Civelek, V N; Deeney, J T; Shalosky, N J et al. (1996) Regulation of pancreatic beta-cell mitochondrial metabolism: influence of Ca2+, substrate and ADP. Biochem J 318 ( Pt 2):615-21
Nilsson, T; Schultz, V; Berggren, P O et al. (1996) Temporal patterns of changes in ATP/ADP ratio, glucose 6-phosphate and cytoplasmic free Ca2+ in glucose-stimulated pancreatic beta-cells. Biochem J 314 ( Pt 1):91-4
Cunningham, B A; Deeney, J T; Bliss, C R et al. (1996) Glucose-induced oscillatory insulin secretion in perifused rat pancreatic islets and clonal beta-cells (HIT). Am J Physiol 271:E702-10
Yaney, G C; Schultz, V; Cunningham, B A et al. (1995) Phosphofructokinase isozymes in pancreatic islets and clonal beta-cells (INS-1). Diabetes 44:1285-9
Hocker, C G; Epstein, I R; Kustin, K et al. (1994) Glycolytic pH oscillations in a flow reactor. Biophys Chem 51:21-35
Juntti-Berggren, L; Civelek, V N; Berggren, P O et al. (1994) Glucose-stimulated increase in cytoplasmic pH precedes increase in free Ca2+ in pancreatic beta-cells. A possible role for pyruvate. J Biol Chem 269:14391-5
Tornheim, K (1994) Kinetic applications using high substrate and competitive inhibitor concentrations to determine Ki or Km. Anal Biochem 221:53-6

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