Hemorrhagic shock from trauma or other etiologies continues to be a major cause of morbidity and mortality. The initial hyperglycemia seen in shock is followed by hypoglycemia and resuscitation failure. Recent data from our laboratory indicated that hemorrhagic shock acutely affects glucose- 6-phosphatase activity and gene expression. Glucose-6- phosphatase is a key enzyme in the hemostatic regulation of blood glucose concentration, which catalyses the final step in gluconeogenesis and glycogenolysis. We have also demonstrated multihormonal regulation of glucose-6-phosphatase gene expression. In order to study the mechanism of changes of glucose-6- phosphatase gene expression in hemorrhagic shock and resuscitation, we propose to study the hormonal regulation of glucose-6-phosphatase activity and mRNA expression. Hemorrhagic shock will be induced in fasted anesthetized rats by reduction of blood pressure to 4OmmHg and maintained in shock for 30 minutes. Control rats will be anesthetized, cannulated and observed for the same time. The liver and kidney from control, hemorrhagic shock and hemorrhagic shock plus lacated Ringer resuscitated rats will be freeze clamped and stored at -70degreesC for future assay of glucose-6-phosphate, fructose-6-phosphate, glucose-6-phosphatase activity and mRNA abundance. Blood samples will be collected at the same time periods to assay catecholamines, corticosterone, insulin and glucagon concentrations in the plasma. Relatively selective pharmacologic antagonists of hormones will be administered prior to hemorrhagic shock and during resuscitation to observe their effects on glucose-6- phosphatase activity and gene expression. Hepatocyte will be isolated from control, hemorrhagic shock and hemorrhagic shock plus resuscitated rats, and will be incubated with agonists to observe their effects on glucose-6-phosphatase activity and gene expression. The results of this study are essential to understand the molecular basis of deranged metabolism in hemorrhagic shock

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM052025-03
Application #
2734763
Study Section
Surgery, Anesthesiology and Trauma Study Section (SAT)
Project Start
1996-07-01
Project End
2000-06-30
Budget Start
1998-07-01
Budget End
2000-06-30
Support Year
3
Fiscal Year
1998
Total Cost
Indirect Cost
Name
State University New York Stony Brook
Department
Emergency Medicine
Type
Schools of Medicine
DUNS #
804878247
City
Stony Brook
State
NY
Country
United States
Zip Code
11794
Maitra, S R; Wang, S; Brathwaite, C E et al. (2000) Alterations in glucose-6-phosphatase gene expression in sepsis. J Trauma 49:38-42
Maitra, S R; Wang, S; El-Maghrabi, M R et al. (2000) Regulation of liver and kidney glucose-6-phosphatase gene expression in hemorrhage and resuscitation. Acad Emerg Med 7:731-8
Maitra, S R; Wang, S; El-Maghrabi, M R (2000) Effects of RU486 on Glu-6-pase gene expression in hemorrhage and resuscitation. Shock 14:578-81
Millis, K; Weybright, P; Campbell, N et al. (1999) Classification of human liposarcoma and lipoma using ex vivo proton NMR spectroscopy. Magn Reson Med 41:257-67
Maitra, S R; Gestring, M L; El-Maghrabi, M R et al. (1999) Endotoxin-induced alterations in hepatic glucose-6-phosphatase activity and gene expression. Mol Cell Biochem 196:79-83
Weybright, P; Millis, K; Campbell, N et al. (1998) Gradient, high-resolution, magic angle spinning 1H nuclear magnetic resonance spectroscopy of intact cells. Magn Reson Med 39:337-45
Millis, K K; Maas, W E; Cory, D G et al. (1997) Gradient, high-resolution, magic-angle spinning nuclear magnetic resonance spectroscopy of human adipocyte tissue. Magn Reson Med 38:399-403
Maitra, S R; Gestring, M; el-Maghrabi, M R (1997) Alterations in hepatic 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase and glucose-6-phosphatase gene expression after hemorrhagic hypotension and resuscitation. Shock 8:385-8