Related Experiment Videos
Upregulation of glucose metabolism by granulocyte-monocyte colony-stimulating factor
A Schuler1, Z Spolarics, C H Lang
1Department of Physiology, Louisiana State University Medical Center, New Orleans 70112.
Abstract:
Alterations of glucose metabolism were investigated for 6 hours following an intraarterial injection of murine recombinant granulocyte-monocyte colony-stimulating factor (GM-CSF) (30 micrograms/kg body weight). GM-CSF resulted in a transient elevation of plasma glucose. The rate of whole body glucose appearance, as measured by infusion of [6-3H] glucose, was increased by about 10% between 0.5 and 3 hours following GM-CSF injection. In vivo glucose utilization of individual tissues was investigated by the tracer 2-deoxyglucose technique. At 30 min, GM-CSF increased glucose utilization by 80-90% in liver and lung, and 50-60% in skin and spleen. At 3 and 6 hours, glucose utilization by these tissues returned toward control levels except for lung. There was a 40-50% increase in glucose utilization by skeletal muscle 30 min after GM-CSF which was sustained for 6 hours. Glucose utilization of testis, ileum and kidney did not change significantly. Plasma concentrations of insulin, glucagon and tumor necrosis factor were not altered in response to GM-CSF. These findings indicate that some of the acute metabolic effects of a short-term administration of GM-CSF are observed in macrophage-rich tissues, and suggest that GM-CSF may be involved in the metabolic upregulation of immunologically active tissues.
Insights
Granulocyte-macrophage colony-stimulating factor (GM-CSF) temporarily increases blood glucose and enhances glucose uptake in tissues like the liver and lungs. This suggests GM-CSF impacts the metabolism of immune-related tissues.
Area of Science:
- Immunology
- Metabolic research
- Biochemistry
Background:
- Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a cytokine involved in immune responses.
- The metabolic effects of GM-CSF, particularly on glucose metabolism, are not fully understood.
Purpose of the Study:
- To investigate the acute alterations in glucose metabolism following intraarterial administration of GM-CSF.
- To determine the impact of GM-CSF on glucose utilization in various tissues in vivo.
Main Methods:
- Murine recombinant GM-CSF was administered intraarterially.
- Plasma glucose levels were monitored.
- Whole-body glucose appearance was measured using [6-3H] glucose infusion.
- Tissue-specific glucose utilization was assessed using the 2-deoxyglucose technique.
Main Results:
- GM-CSF caused a transient elevation in plasma glucose.
- Whole-body glucose appearance increased by approximately 10% between 0.5 and 3 hours.
- Significant increases in glucose utilization were observed in liver, lung, skin, and spleen at 30 minutes post-injection.
- Skeletal muscle showed a sustained increase in glucose utilization for 6 hours.
- Insulin, glucagon, and tumor necrosis factor levels remained unchanged.
Conclusions:
- Acute administration of GM-CSF affects glucose metabolism, particularly in macrophage-rich tissues.
- GM-CSF may play a role in the metabolic upregulation of immunologically active tissues.
- The observed metabolic changes are independent of alterations in insulin, glucagon, or TNF levels.