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Query: UMLS:C0036690 (sepsis)
 59,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We investigated whether the multiple pathophysiological signals generated in a peritonitis septic model alter the mRNA levels of glycolytic and gluconeogenic enzymes, and whether these alterations are associated with glucose dyshomeostasis. Rats were sham-operated in the control group, and peritonitis sepsis was produced by a 1 cm cecal incision in the septic group. At 2, 4, and 6 hr post-surgery, total cellular RNAs were isolated from livers, and Northern blots performed to measure mRNA levels of aldolase B (ADL), lactate dehydrogenase (LDH), pyruvate kinase (PK), phosphoenolpyruvate carboxykinase (PEPCK), and glucokinase (GK). Hepatic PEPCK enzymatic activity was measured by condensing 14CO2 with phosphoenolpyruvate (PEP) to form malate. Serum glucose concentrations were also measured. We found the following: At 2 hr of peritonitis sepsis, serum glucose concentrations, mRNA levels of all enzymes, and PEPCK enzymatic activity increased over control levels. At 4 hr of peritonitis sepsis, serum glucose concentrations and mRNA levels of GK and PK continued to increase; mRNA levels of all other enzymes, as well as PEPCK enzymatic activity decreased to or below control levels. At 6 hr of peritonitis sepsis, serum glucose concentrations, mRNA levels of all enzymes, and PEPCK enzymatic activity decreased to or below control levels. We concluded that sepsis affects mRNA levels of glycolytic and gluconeogenic enzymes at the transcriptional level, and that these alterations are associated with glucose dyshomeostasis.
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PMID:Altered levels of mRNA encoding enzymes of hepatic glucose metabolism in septic rats. 840 44

Despite a detailed understanding of their metabolism, mitochondria often behave anomalously. In particular, global suppression of mitochondrial metabolism and metabolite exchange occurs in apoptosis, ischemia and anoxia, cytopathic hypoxia of sepsis and multiple organ failure, alcoholic liver disease, aerobic glycolysis in cancer cells (Warburg effect) and unstimulated pancreatic beta cells. Here, we propose that closure of voltage-dependent anion channels (VDAC) in the mitochondrial outer membrane accounts for global mitochondrial suppression. In anoxia, cytopathic hypoxia and ethanol treatment, reactive oxygen and nitrogen species, cytokines, kinase cascades and increased NADH act to inhibit VDAC conductance and promote selective oxidation of membrane-permeable respiratory substrates like short chain fatty acids and acetaldehyde. In cancer cells, highly expressed hexokinase binds to and inhibits VDAC to suppress mitochondrial function while stimulating glycolysis, but an escape mechanism intervenes when glucose-6-phosphate accumulates and dissociates hexokinase from VDAC. Similarly, glucokinase binds mitochondria of insulin-secreting beta cells, possibly blocking VDAC and suppressing mitochondrial function. We propose that glucose metabolism leads to glucose-6-phosphate-dependent unbinding of glucokinase, relief of VDAC inhibition, release of ATP from mitochondria and ATP-dependent insulin release. In support of the overall proposal, ethanol treatment of isolated rat hepatocytes inhibited mitochondrial respiration and accessibility to adenylate kinase in the intermembrane space, effects that were overcome by digitonin permeabilization of the outer membrane. Overall, these considerations suggest that VDAC is a dynamic regulator, or governator, of global mitochondrial function both in health and disease.
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PMID:Voltage-dependent anion channel (VDAC) as mitochondrial governator--thinking outside the box. 1630 70