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

Sepsis is a major catabolic insult resulting in modifications in carbohydrate and fat energy metabolism, and leading to increased muscle breakdown and nitrogen loss. Insulin resistance, which develops in sepsis, decreases glucose utilization, but plasma insulin levels are sufficiently elevated to prevent lipolysis, resulting in a further energy deficit. The availability of fuels in sepsis is therefore limited, and the body resorts to muscle breakdown, gluconeogenesis, and amino acid oxidation for energy supply. Previous work has not defined, however, the exact alterations in amino acid metabolism. Therefore, the following studies were undertaken. Blood samples were drawn from fifteen patients in whom the diagnosis of sepsis was clinically established; the samples were analyzed for amino acid, beta-hydroxyphenylethanolamines, glucose, insulin and glucagon concentrations. The plasma amino acid pattern observed was characterized by an increase in total amino acid content, due mainly to high levels of the aromatic amino acids (phenylalanine and tyrosine) and the sulfur-containing amino acids (taurine, cystine and methionine). Alanine, aspartic acid, glutamic acid and proline were also elevated, but to a lesser degree. The branched chain amino acids (valine, leucine and isoleucine) were within normal limits, as were glycine, serine, threonine, lysine, histidine and tryptophan. Those patients who did not survive sepsis had higher levels of aromatic and sulfur-containing amino acids as compared to those patients surviving sepsis. On the other hand, those patients surviving sepsis had higher levels of alanine and the branched chain amino acids. In a second group of five patients with overwhelming sepsis accompanied by a state of metabolic encephalopathy, a parenteral nutrition solution consisting of 23% dextrose, and an amino acid formulation enriched with branched chain amino acids was administered. In these five patients, normalization of the plasma amino acid pattern and reversal of encephalopathy was observed. The following sequence of events may be postulated: The septic patient develops insulin resistance in the peripheral tissues, primarily muscle, while the adipose tissue is much less affected. The insulin resistance and the inability to utilize fat leads to increased muscle proteolysis. Muscle breakdown results in release into the blood of enormous amounts of various amino acids; the muscle itself is able to oxidize the branched chain amino acids, supplying the muscles' own energy requirements and alanine for gluconeogenesis. The extensive muscle proteolysis coupled with relative hepatic insufficiency occurring early in sepsis results in the appearance in the plasma of high levels of most of the amino acids present in muscle, particularly the aromatic and the sulfur-containing amino acids. The outcome of patients with sepsis might be positively affected by combined therapy with glucose, insulin and branched chain amino acids.
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PMID:Amino acid derangements in patients with sepsis: treatment with branched chain amino acid rich infusions. 9 98

Glucose intolerance occurs in patients with sepsis, and resistance to insulin has been thought to be part of this process. To study this phenomenon, peritonitis was produced in rats by cecal ligation and puncture. One group was killed ten hours later (early sepsis). A second group of rats was killed 16 to 24 hours after ligation, just prior to their expected death (late sepsis). Insulin stimulated glucose uptake to the same extent in muscles from rats in early sepsis, late sepsis, and from control rats. Even at an insulin concentration that produced submaximal stimulation of glucose uptake, no difference in glucose uptake between the three groups of muscles was observed. Thus, there was no resistance to the stimulatory action of insulin on glucose uptake by skeletal muscle during early and late sepsis. However, basal glucose uptake by isolated soleus muscle from animals in late sepsis was significantly increased compared with controls when these muscles were incubated in an aerobic environment. Under anaerobic conditions, glucose uptake in these two groups of muscles increased to the same level. This indicates that there is some stimulus that increases glucose uptake in late peritonitis and may explain the hypoglycemia of late experimental or untreated sepsis. This stimulus could be hypoxia or some other factor resulting from decreased blood flow and increased anaerobic metabolism.
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PMID:Studies of peripheral glucose uptake during sepsis. 45 60

Insulin glucose therapy can correct hyponatraemia and renal sodium retention in burns, sepsis and circulatory failure. A case of fulminant hepatic failure (F.H.F.) is described in which the same effect was observed. Insulin was thought to have corrected abnormal cell membrane permeability. The actions of insulin are discussed in relation to its possible role in the management of F.H.F.
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PMID:The effects of insulin glucose administration in fulminant hepatic failure. 69 Mar 22

The anabolic effect of insulin in skeletal muscle reflects increased protein synthesis and reduced protein degradation. Insulin stimulates protein synthesis mainly at the translational level by enhancing peptide chain initiation. The mechanism by which the hormone reduces protein breakdown is less well understood, but inhibition of the lysosomal pathway is probably an important component. Sepsis results in pronounced muscle catabolism, mainly reflecting increased protein breakdown, particularly myofibrillar protein breakdown, and a less prominent inhibition of protein synthesis. There is evidence that muscle protein breakdown becomes resistant to the effect of insulin during sepsis, probably at the postreceptor level. This insulin resistance may be mediated by increased beta-adrenoreceptor activity. In contrast, the stimulatory effect of insulin on muscle protein synthesis and amino acid transport is maintained during sepsis. The regulatory effect of insulin on muscle protein metabolism may be affected by other catabolic conditions as well, e.g., fasting, denervation, burn injury, and trauma.
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PMID:Regulation by insulin of muscle protein metabolism during sepsis and other catabolic conditions. 148 52

Insulin-like growth factor 1 (IGF-1) is regulated by nutritional intake independently of growth hormone and may be a better nutritional indicator than the plasma proteins. This possibility was investigated in six malnourished inpatients, who suffered sepsis, surgical trauma, or both and who received total parenteral nutrition (TPN) for 10-35 days. Both plasma IGF-1 and pre-albumin showed (P less than 0.05) increases during TPN from baseline values of 0.042-0.42 U/mL (median, 0.11) and 59-156 mg/L (median, 108), respectively, to maxima of 0.19-1.12 U/mL (median, 0.63) and 140-363 mg/L (median, 203). Statistically significant (P less than 0.05) positive correlation occurred between nitrogen balance (range, -7.5 to +11.0 g/day) and IGF-1 or pre-albumin. Correlation between nitrogen balance and IGF-1 is preserved during the acute phase response to tissue injury when C-reactive protein (CRP) varies in the range 40-248 mg/L. Under these circumstances, the correlation between nitrogen balance and pre-albumin is, in contrast, abolished. These results suggest that IGF-1 behaves as a valid index of nutritional adequacy during parenteral feeding whereas pre-albumin reflects mainly the acute phase response.
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PMID:Insulin-like growth factor 1: a valid nutritional indicator during parenteral feeding of patients suffering an acute phase response. 162 15

The hepatic toxicity of TPN that is seen clinically appears to be multifactorial in origin. Most patients develop a combination of hepatic steatosis with evidence of cholestasis and abnormalities in liver function. The model that we have studied is one of pure hepatic steatosis since, on repeated study, these rats do not develop any liver function abnormalities. It is unclear whether this is related to the fact that these are short-term experiments, that rat livers respond differently from humans, or that rats do not have gallbladders. It has not been possible to carry these experiments out beyond 3 weeks since the rats develop bacterial colonization of the central lines as well as evidence of line sepsis. thus confounding the issue of hepatic toxicity being due to the TPN or to sepsis. One hypothesis is that hepatic steatosis is an early marker of liver toxicity and that prevention or reversal of hepatic steatosis may protect the liver from further abnormality. Insulin and glucagon seem to play a critical role in the development of TPN-associated hepatic steatosis. Specifically, an elevated portal venous insulin-glucagon molar ratio appears to be the primary stimulus and any treatment that lowers this ratio should diminish hepatic steatosis. The use of glucagon as a treatment modality is new. We have found no evident side effects of low dose glucagon in rats when it is added to the TPN solution. Glutamine has received much attention recently as a nutritional pharmacological agent in ameliorating some of the intestinal complications of parenteral nutrition and is well tolerated when administered appropriately. Intravenous lipid administration is an important nonprotein calorie source, especially when a high dextrose base cannot be used, and plays a role as well in preventing the development of hepatic steatosis. Thus, it is suggested that the clinical treatment of hepatic steatosis during TPN can be safely performed using any one, or a combination, of these modalities and without having to discontinue the TPN infusions. Since we observed no deterioration of liver function in rats receiving TPN for up to 2 weeks, we cannot completely relate these findings and recommendations to the hepatic dysfunction seen clinically with the use of TPN. Additional study will be required before this can be conclusively determined.
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PMID:Pathogenesis of hepatic steatosis during total parenteral nutrition. 190 28

Insulin resistance is a cause for morning hyperglycemia seen in diabetic patients. Other reasons for morning hyperglycemia should be eliminated by performing an insulin response test. Once insulin resistance has been established as the cause of hyperglycemia, a step-by-step process should be used to establish the cause of the insulin resistance. Common causes of insulin resistance include hyperadrenocorticism, acromegaly, hyperthyroidism, and obesity. Hepatic disease, renal insufficiency, and sepsis are other causes of insulin resistance in practice. Less common causes include insulin antibodies, pregnancy, neoplasia, hyperandrogenism, and pheochromocytoma. If the underlying cause cannot be found or resolved, then increased doses of insulin are required to manage the hyperglycemia.
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PMID:Problems in diabetes mellitus management. Insulin resistance. 213 77

Gram-negative hypermetabolic sepsis has been previously reported to produce whole body insulin resistance. The present study was performed to determine in vivo which tissues are responsible for the sepsis-induced decrease in insulin-mediated glucose uptake (IMGU), and whether that decrease was related to a change in regional blood flow. Vascular catheters were placed in rats and sepsis was induced by subcutaneous injections of Escherichia coli. Insulin action was assessed 20 hours after the first injection of bacteria by the combined use of the euglycemic hyperinsulinemic clamp and the tracer 2-deoxyglucose (dGlc) technique. Insulin was infused at various rates in separate groups of septic and nonseptic rats for 3 hours to produce steady-state insulin levels between 70 and 20,000 microU/mL. Rats were injected with [U-14C]-dGlc 140 minutes after the start of the euglycemic hyperinsulinemic clamp for the determination of the glucose metabolic rate (Rg) in selected tissues. The maximal response to insulin was decreased 30% to 40% in the gastrocnemius, and in the red and white quadriceps. The former two muscles also showed a decrease in insulin sensitivity. However, the insulin resistance seen in hindlimb muscles was not evident in all muscles of the body, since IMGU by abdominal muscle, diaphragm, and heart was not impaired by sepsis. The basal Rg by skin, spleen, ileum, and lung was increased by sepsis, and was higher than the insulin-stimulated increases in Rg by these tissues in nonseptic animals. Cardiac output was similar in septic and nonseptic rats and did not change during the infusion of insulin. Under basal conditions, sepsis appeared to redistribute blood flow away from the red quadriceps and skin, and increased flow to the liver (arterial), lung, and small intestine. When plasma insulin levels were elevated, hepatic arterial blood flow was increased, and flow to the red quadriceps and skin was decreased in nonseptic animals. Hyperinsulinemia did not produce any consistent change in regional blood flow in septic animals. The results of this study indicate that a decrease rate of IMGU in muscle is primarily responsible for the whole body insulin resistance seen during hypermetabolic sepsis, and that the impairment of insulin action in skeletal muscle is not dependent on fiber type or to changes in blood flow.
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PMID:Insulin-mediated glucose uptake by individual tissues during sepsis. 221 56

Interleukin-2 (IL-2) is secreted during the immune response to trauma, sepsis, and transplant rejection. Its role in the development of the metabolic abnormalities observed in these circumstances is not well defined. We studied the clinical, hormonal, and metabolic response to a 5-day IL-2 infusion (3 x 10(6) U/m2/day) of nine patients with metastatic renal carcinoma. IL-2 induced systemic manifestations after a latent period of 4 h (fever, tachycardia) or 8 h (hypotension). These manifestations persisted until the end of the infusion. Insulin levels were not modified. Among the stress hormones, cortisol increased at the onset of fever and tachycardia, whereas the rise in catecholamines occurred later (24 h) and appeared more as a response to the development of hypotension. The only metabolic effects observed were a late (third day) rise of lactate and a late and transient (third to fourth day) decrease of glycerol and nonesterified fatty acids. These metabolic modifications were temporally related to the development of hypotension and result more likely from low tissue perfusion rather than from a direct or hormone-mediated effect of IL-2.
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PMID:Hormonal and metabolic effects of chronic interleukin-2 infusion in cancer patients. 234 64

Sepsis, like trauma, causes proteolysis of skeletal muscle. Insulin normally protects against muscle protein degradation. In earlier work using a rat muscle preparation, insulin inhibition of proteolysis decreased in the presence of plasma from injured patients. The current experiments tested the effect of plasma from septic patients on insulin inhibition in the same model. The mean value of protein degradation among eight septic plasma samples was 49% greater than the mean value among five normal plasma samples in soleus muscle and 45% greater in extensor digitorum longus muscle. In the presence of insulin, 10(3) mU/L, the increases in degradation with septic plasma were 42% in soleus muscle and 48% in extensor digitorum longus muscle. Insulin reduced degradation an average of 6% (soleus) and 10% (extensor digitorum longus) in normal plasma and 10% (soleus) and 8% (extensor digitorum longus) in septic plasma. In contrast to results of other studies, these experiments show that the protective effect of a moderate concentration of insulin in resisting muscle protein degradation is not significantly different in the muscle protein degradation is not significantly different in the presence of septic human plasma compared with normal plasma. This finding supports clinical efforts to decrease proteolysis in septic patients by the administration of insulin.
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PMID:Insulin protects against muscle proteolysis induced by septic plasma. 240 29


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