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Query: UMLS:C0243026 (sepsis)
 52,417 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The present study was performed to determine whether insulin resistance, independent of the prevailing hormonal milieu, occurs in the liver during sepsis. To determine this, sepsis was produced in rats by cecal ligation and puncture (CLP). Six hours later, when the rats were in the early hypermetabolic phase of sepsis, the livers were isolated and perfused with Krebs-HCO3 buffer using a nonrecirculating system. The effects of various concentrations of insulin on the gluconeogenic response to lactate and phenylephrine stimulation were determined. In the absence of insulin and phenylephrine, there was no difference in the rates of glucose production from lactate between septic and sham-operated rats. The gluconeogenic response to phenylephrine stimulation was, however, significantly depressed in the livers from septic rats. Addition of 50 microU insulin/ml resulted in an inhibition of the phenylephrine-stimulated glucose release from livers from sham-operated rats. This inhibition was maximal at 100 microU insulin/ml. In contrast, significant inhibition of phenylephrine-stimulated glucose release from livers from septic rats was only observed in the presence of 2,000 microU insulin/ml. These results demonstrate that even during the early, hypermetabolic phase of sepsis, depressed hormonally stimulated hepatic gluconeogenic capability occurs. In addition, livers from septic rats exhibited a resistance to the effects of insulin on gluconeogenesis. This resistance may account, at least in part, for accelerated gluconeogenesis in spite of hyperinsulinemia in early sepsis.
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PMID:Insulin resistance and depressed gluconeogenic capability during early hyperglycemic sepsis. 638 45

Although it is known that hepatic failure occurs in late sepsis, it is not known whether there are alterations in hepatocellular function in early sepsis when hyperdynamic circulation exists in conjunction with hyperglycemia and hyperinsulinemia. To study this, indocyanine green (ICG) clearance and serum levels of hepatic enzymes were measured during early and late sepsis. Sepsis in rats was produced by cecal ligation and puncture (CLP). Ten hours following CLP (early sepsis) total hepatic blood flow (THBF) as measured by hydrogen polarography increased from 23.9 +/- 1.1 to 30.6 +/- 1.4 (ml/min/100 gm). ICG (5 mg/kg body weight--BW) was given intravenously and sequential blood samples taken to determine ICG clearance. ICG half-times (T/2) were 4.99 +/- 0.15 and 6.57 +/- 0.51 minutes for sham-operated and early sepsis rats, respectively (mean +/- S.E., P less than 0.01). SGOT and SGPT levels (IU/ml) increased from 38.1 +/- 0.6 to 69.8 +/- 2.6 and 9.9 +/- 0.4 to 25.6 +/- 1.5, respectively (P less than 0.001). Thus the T/2 of ICG as well as serum levels of liver enzymes increased significantly during early sepsis. Eight additional rats underwent CLP and were tested 16 hours later (late sepsis). THBF in late sepsis decreased to 15.5 +/- 0.5 ml/min/100 gm. ICG T/2 at that time was 8.2 +/- 0.48 min and SGOT and SGPT level were 132 +/- 14.5 and 42 +/- 3.4, respectively (P less than 0.001). These results indicate that heptocellular dysfunction occurs even in the early period of sepsis when THBF is increased. Progressive dysfunction occurs in late sepsis concomitant with a decrease in THBF.
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PMID:Hepatocellular dysfunction in early sepsis despite increased hepatic blood flow. 734 87

This study was performed to characterize and compare the actions of insulin on hepatic glucose production and peripheral glucose utilization during infusions of endotoxin, tumor necrosis factor (TNF), interleukin-1 (IL-1), and a combination of IL-1 and TNF in the rat. The euglycemic hyperinsulinemic clamp technique was combined with a primed-constant tracer infusion of high-performance liquid chromatography (HPLC)-purified 3H-3-glucose for estimation of whole-body glucose appearance and utilization rates; 14C-deoxyglucose (14C-DG) uptake was also measured in specific tissues following intravenous bolus administration. As expected, acute endotoxemia resulted in a significant reduction of glucose infusion during the clamp procedure (insulin concentration, 100 microU/mL), suggesting decreased insulin action. Similarly, infusion of TNF decreased the rate of glucose infusion necessary to maintain euglycemia. However, differences between endotoxin- and cytokine-treated rats were noted in whole-body glucose appearance (or disappearance) rates. Whereas endotoxin infusion predominantly decreased whole-body glucose uptake, suggesting diminished utilization in skeletal muscles, cytokine infusions were associated with a measurable hepatic glucose output despite hyperinsulinemia. In contrast, both cytokine and endotoxin administration decreased the rate of 14C-DG uptake by muscle tissue. These results demonstrate that TNF, IL-1, and endotoxin can induce a state of insulin resistance when infused continuously; the results also emphasize the complexity of regulation of glucose homeostasis during infection and sepsis.
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PMID:Effects of systemic infusions of endotoxin, tumor necrosis factor, and interleukin-1 on glucose metabolism in the rat: relationship to endogenous glucose production and peripheral tissue glucose uptake. 813 74

Hypoglycaemia is a relatively common cause for referral of patients to the accident and emergency departments of hospitals but most of it is iatrogenic. Occasionally, however, hypoglycaemia is due to any one of up to a hundred different disorders. In some, hypoglycaemia is the cause of intermittent neuroglycopenic symptoms that lead to their referral to medical outpatients for investigation. Only the most important are discussed here. Hyperinsulinism due to abnormal beta-cell function is an uncommon but important cause of spontaneous hypoglycaemia. The diagnosis is suspected from the history of episodes of altered consciousness confirmed by demonstrating raised plasma insulin, C-peptide and proinsulin levels in peripheral blood in the presence of hypoglycaemia. Differentiation of the various causes of endogenous hyperinsulinism before surgery is difficult if not impossible and the low predictive value of most of the localizing techniques that are available makes them an additional and unnecessary cost, producing little clinical benefit. Hypoglycaemia caused by non-islet cell tumours (NICTH) is seemingly rarer than hyperinsulinism from insulinoma and tends to occur in older patients. The clinical features are similar to those of hyperinsulinism but laboratory investigation reveals appropriately depressed plasma insulin, C-peptide and proinsulin levels in the presence of hypoglycaemia. The plasma IGF-II:IGF-I ratio is characteristically high and the concentration of the E-domain of proIGF-II is raised. Autoimmune hypoglycaemia is more common in some countries than others and is most often due to autoantibodies to insulin (AIS). It may also be caused by autoantibodies to the insulin receptor and possibly to autoantibodies that are stimulatory to pancreatic beta-cells. Contrary to popular belief, idiopathic reactive hypoglycaemia is rare and only one of the possible causes of the postprandial syndrome. It is characterized by a low blood glucose concentration in blood collected during a spontaneous symptomatic episode but not at other times. Its cause is unknown. Other causes of hypoglycaemia include endocrinopathies of various kinds; sepsis including malaria; congestive cardiac failure; hepatic and renal insufficiencies; diverse inborn errors of metabolism; and exogenous toxins, of which alcohol is probably the commonest.
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PMID:Hypoglycaemia in the adult. 837 12

Metformin is a biguanide that can used alone or in combination with sulfonylureas or insulin in the treatment of non-insulin-dependent diabetes mellitus (NIDDM). Since biguanides do not increase pancreatic insulin secretion, they are referred to as antihyperglycemic agents, as opposed to hypoglycemic agents. Biguanides reduce hyperglycemia by increasing, insulin sensitivity, decreasing glucose absorption, and inhibiting hepatic gluconeogenesis. Advantages of metformin include achieving glycemic control without exacerbating weight gain or hyperinsulinemia and beneficially affecting serum cholesterol concentrations. Although metformin has the potential to cause lactic acidosis, the incidence is significantly lower compared with phenformin. Risk factors for lactic acidosis include renal serum creatinine > 1.5 mg/dL and cardiovascular, pulmonary, and hepatic disease. Metformin should be temporarily discontinued prior to surgery and before administration of radiologic intravenous contrast, and in patients with sepsis, severe gastrointestinal disease, trauma, and acute cardiovascular events.
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PMID:Metformin: a new treatment option for non-insulin-dependent diabetes mellitus. 865 73

Circulating leptin concentrations are raised in animal models of inflammation and sepsis. The purpose of this study was to determine the effect of sepsis on serum leptin concentration in humans and to examine the relationship between leptin and the metabolic consequences of sepsis. Resting energy expenditure, insulin sensitivity, and fasting serum leptin, plasma insulin, and cortisol concentrations were measured in 20 subjects with intra-abdominal sepsis and 20 healthy control subjects, before and during a 2-h period of euglycemic hyperinsulinemia. Fasting serum leptin concentrations were similar in septic and control subjects. In simple regression analysis, serum leptin concentrations correlated significantly with percent body fat in both septic patients (r = 0. 64, P < 0.005) and healthy subjects (r = 0.75, P < 0.0001). Multiple regression analyses additionally indicated that percent body fat, fasting plasma insulin, and plasma cortisol, but not sepsis, were significant and independent determinants of serum leptin concentration. No relationship between leptin and resting energy expenditure or insulin sensitivity was identifiable. A major metabolic role for leptin in human sepsis therefore appears unlikely.
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PMID:Serum leptin concentrations and their relation to metabolic abnormalities in human sepsis. 1019 1

Cellular swelling has emerged as an important initiator of metabolic and proliferative changes in various cells. Because of the unique regenerative capacity of the adult liver, researchers have delineated key intracellular signals that are activated following mitogens, injury, and partial hepatectomy. Although hepatocellular swelling is commonly observed following these regenerative stimuli, only recently has the relationship between cell volume increase and proliferative activity been investigated; to date, the data implicating cell volume increase with hepatocyte regeneration has been mostly indirect. Hepatocyte swelling has been demonstrated in various clinical scenarios from sepsis, hepatic resection, ischemia-reperfusion injury, glucocorticoid excess, and hyperinsulinemia. Using various in vivo and in vitro models of hepatocyte swelling, particularly hypo-osmotic stress, investigators have demonstrated changes in cellular structure: (1) cell membrane stretch, (2) cytoskeletal microtubule and microfilament reorganization, and (3) alterations in cytoskeletal-membrane complexes. Similar studies have demonstrated a causal relationship between cell volume increase and intracellular signals: (1) activation of cytoplasmic signaling cascades such as MAPKs, PI-3-K, and PKC, (2) activation of proliferative transcription factors NF-kappaB, AP-1, STATs, C/EBPs, and (3) transcription of metabolic and immediate early genes of regeneration. Through mechanotransduction, or the translation of physical changes to chemical signals, cell volume is a potent effector of these signaling events. Growing evidence demonstrates a link between these physical and chemical changes in the swelling-mediated growth in the liver.
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PMID:Impact of cell swelling on proliferative signal transduction in the liver. 1150 Sep 54

Hypocalcemia and hypomagnesemia are common in horses with sepsis and endotoxemia. We hypothesize that endotoxemia triggers a systemic inflammatory response that results in hypocalcemia and hypomagnesemia. The goal of this study was to determine the effect of endotoxin (lipopolysaccharide [LPS]) administration to healthy horses on serum parathyroid hormone (PTH), ionized calcium (Ca2+) and total calcium (tCa), ionized magnesium (Mg2+) and total magnesium (tMg), phosphate (Pi), potassium (K+), sodium (Na+), chloride (Cl-), and insulin concentrations, and on the urinary excretion of these electrolytes. Twelve mares were infused with Escherichia coli LPS (30 ng/kg/h i.v.) for 1 hour. Six mares were infused with saline (controls). In LPS-infused horses, heart rate increased significantly from (mean +/- SD) 40.0 +/- 1.3 to 70.0 +/- 9.0 beats/min, respiratory rate from 12.7 +/- 1.0 to 21.1 +/- 3.0 breaths/min, body temperature from 37.4 +/- 0.3 to 38.9 +/- 0.6 degrees C, and tumor necrosis factor-alpha concentrations from 6.6 +/- 3.5 to 507 +/- 260 pg/mL (P < .05). White blood cell count decreased significantly from 7570 +/- 600 to 1960 +/- 560 cells/ microL. Serum concentrations of Ca2+ decreased from 6.5 +/- 0.3 to 6.0 +/- 0.3 mg/dL, of Mg2+ from 0.53 +/- 0.06 to 0.43 +/- 0.04 mM, of tMg from 0.78 +/- 0.05 to 0.62 +/- 0.08 mM, of K+ from 4.3 +/- 0.4 to 3.0 +/- 0.5 mEq/L, and of Pi from 3.4 +/- 0.5 to 1.7 +/- 0.5 mg/dL (all P < .05). PTH increased significantly from 1.3 +/- 0.4 to 6.0 +/- 5.2 pM; however, in some horses (n=2), PTH did not increase despite hypocalcemia. Insulin increased significantly from 9.4 +/- 3.6 to 50.5 +/- 9.6 microIU/mL (n=3). Urinary fractional excretion of Ca2+ decreased significantly from 4.7 +/- 1.4 to 1.7 +/- 1.2%, of Mg2+ from 36.6 +/- 6.5 to 11.7 +/- 7.3%, and of K+ from 37.9 +/- 11.3 to 17.7 +/- 6.2%. Fractional excretion of Pi increased from 0.02 +/- 0.02 to 0.14 +/- 0.07% and of Na+ from 0.26 +/- 0.13% to 1.2 +/- 0.5%. No changes were found in serum tCa, Na+, and Cl- concentrations. In conclusion, endotoxemia in horses resulted in electrolyte abnormalities that included hypocalcemia, hypomagnesemia, hypokalemia, hypophosphatemia, and increased serum PTH and insulin concentrations.
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PMID:Alterations in serum parathyroid hormone and electrolyte concentrations and urinary excretion of electrolytes in horses with induced endotoxemia. 1582 68

The normal endothelium produces a number of vasodilator substances such as nitric oxide (NO) and prostacyclin (PGI2) that regulate vasomotor tone, reduce platelet aggregation, and inhibit the recruitment and activity of inflammatory cells. The functions of vascular endothelial cells are disturbed in diabetic patients. The major cause for mortality and a great percent of morbidity in patients with diabetes mellitus is atherosclerosis. Insulin has recently been shown to stimulate NO release and the expression of NO synthase by the endothelium. Insulin is thus a vasodilator, has anti-platelet activity, and now has been shown to be anti-inflammatory and thus, potentially anti-atherogenic. Similar anti-inflammatory effects of thiazolidenediones (TZDs), troglitazone, and rosiglitazone suggest that they too may have potential anti-atherogenic effects. These effects of insulin and TZDs are of importance since the two major states of insulin resistance, obesity and type 2 diabetes, are associated with a marked increase in atherosclerosis, coronary heart disease, and stroke. These recent observations have extremely important implications for the understanding of the pathogenesis of atherosclerosis in insulin-resistant states and for a rational approach to their comprehensive treatment, including the prevention of atherosclerosis and its complications. This review challenges the previously proposed hypothesis that hyperinsulinemia represents a common pathophysiological pathway of diabetic complications and advances our hypothesis that insulin, through its effect on the endothelium, leucocytes, and platelets, has anti-inflammatory and thus potentially anti-atherogenic properties. Furthermore, through its anti-inflammatory effects, its use improves clinical outcomes in at least two clinical states characterized by profound inflammation-acute myocardial infarction and sepsis.
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PMID:Endothelium, inflammation, and diabetes. 1837 Jun 22

In diabetes mellitus and sepsis, low erythrocyte glutathione (GSH) concentrations are found. Whether this is caused by lowered GSH production has not been clarified. To obtain insight in the relationship between erythrocyte GSH concentrations and GSH production, GSH kinetics were measured in healthy male volunteers during 4 different clamps (low-dose or medium-dose insulin [100 or 400 pmol/L] and euglycemia or hyperglycemia [5 or 12 mmol/L]) in a control setting (n = 6; all 4 clamps in the same subject) or after systemic administration of lipopolysaccharide (to mimic sepsis) (4 groups of n = 6; each clamp in a different subject). Hyperinsulinemia decreased erythrocyte GSH concentration (P = .042), but did not affect fractional synthetic rate (FSR) of GSH. Hyperglycemia did not affect erythrocyte GSH concentration, but decreased FSR of GSH (P = .025). Lipopolysaccharide decreased erythrocyte GSH concentration (P < .001), but increased FSR of erythrocyte GSH (P = .035). Depending on the metabolic circumstances, we found either stable GSH concentrations with lower production rates or decreased levels with either no change or an increase in production rate. Based upon these data, it seems inappropriate to infer conclusions about changes in synthesis rate of GSH from changes in its concentration.
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PMID:Erythrocyte glutathione concentration and production during hyperinsulinemia, hyperglycemia, and endotoxemia in healthy humans. 2085 Aug 47


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