Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036690 (sepsis)
 59,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The covalent modification of receptor proteins via phosphorylation and dephosphorylation is one of the principal mechanisms controlling carbohydrate metabolism and is known to be regulated by various protein kinases. Recent studies indicated that many hormones may exert their effects on cellular metabolism by regulating intracellular c-AMP levels and by activating a c-AMP dependent protein kinase, i.e., protein kinase A. The metabolic disturbances during sepsis are characterized by an initial hyperglycemia followed by a progressive hypoglycemia and a depletion of hepatic glycogen content. The latter is coupled with a slowdown in glycogenesis, an accelerated glycogenolysis, and a depression in gluconeogenesis in the liver. Since the liver is the major organ that regulates the homeostatic level of blood glucose, it is conceivable that the sepsis-induced glucose dyshomeostasis might be mediated by changes in protein kinase activity and the kinetic characteristics of enzymes. The present experiment was designed to study the correlation between protein kinase A and the pathophysiology of hepatic glucose dyshomeostasis during sepsis. Sepsis was induced in rats by cecal ligation and puncture (CLP). Late sepsis occurred 18 hours after CLP. Protein kinase A was extracted from the rat livers by acid precipitation and ammonium sulfate fractionation, and then partially purified by DEAE-cellulose. The results show that in the late sepsis, type-I protein kinase A (eluted at low ionic strength) activity was significantly decreased by 34-52% (P < 0.01). The kinetic parameters such as Vmax's for ATP, histone, and c-AMP were also significantly decreased from the control values of 6.1 +/- 0.9, 5.4 +/- 0.8, and 5.1 +/- 1.9 nmoles/mg.min. to 3.6 +/- 0.5, 2.8 +/- 0.3, and 2.5 +/- 0.5 nmoles/mg.min., respectively. Analysis using Hill's equation indicates that the S0.5 and n (Hill coefficient) values of the various substrates and activators for type-I protein kinase A remained unchanged. In the case of type-II protein kinase A (eluted at high ionic strength), the Vmax, S0.5, and n values for ATP, histone, and c-AMP were unchanged during late sepsis. The results of the present study indicate that the activities and kinetic characteristics of type I protein kinase A in rat liver are modified during late sepsis. Since protein kinase A is known to regulate glucose metabolism through adrenergic receptor mediation, these findings may have a pathophysiological significance in the understanding of hepatic glucose dyshomeostasis during sepsis.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Kinetic studies of protein kinase A in rat liver during late sepsis]. 129 61

We report a prospective, non-blind, randomised, multicentre, parallel group, multinational investigation to compare ceftazidime to aminoglycoside based regimens as empirical treatment in 1316 cases of suspected sepsis in the newborn. In each of the 15 study centres either ceftazidime alone (CAZ) or ceftazidime + ampicillin (CAZ + AMP) was compared to an amino-glycoside/ampicillin combination (AG + AMP). In all cases treatment was based on "an intention to treat". Bacteria considered to be pathogenic were isolated from 176/1316 (13.4%) patients. The incidence of proven infection varied from 39% in a Yugoslav centre to 6% in a British centre; a further 489/1316 (37.1%) patients fulfilled the criteria for clinically suspected sepsis. A total of 210 bacterial isolates from 197 infection sites in 176 patients were considered to be clinically significant. The cure rate for evaluable patients with proven infection who were treated with CAZ + AMP (97%, 30/31) was significantly higher than that for the corresponding patients treated with AG + AMP (66%, 26/39), (P < 0.002). The difference in cure rate between CAZ monotherapy (79%, 34/43) and AG + AMP (86%, 32/37) was not significant. Treatment failed in 28/150 (18.7%) evaluable patients. There were significantly fewer failures (P < 0.001) with CAZ + AMP than with AG + AMP therapy. There were 55 staphylococcal infections. Treatment was successful in 16/19 evaluable patients treated with CAZ or CAZ + AMP and in 16/29 evaluable patients treated with AG + AMP. None of the study centres encountered problems with ceftazidime resistant bacteria. The cure rate for patients with only clinical and radiological evidence of sepsis was greater than 94% in all treatment groups.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:A comparison of ceftazidime and aminoglycoside based regimens as empirical treatment in 1316 cases of suspected sepsis in the newborn. European Society for Paediatric Infectious Diseases--Neonatal Sepsis Study Group. 147 40

1. The metabolism of glutamine and alanine in the lung was studied in rats made septic by a caecal ligation and puncture technique. 2. The blood glucose concentration was not significantly different in septic rats, but blood pyruvate, lactate, glutamine and alanine concentrations were markedly increased as compared with sham-operated rats. Conversely, blood ketone body and plasma cholesterol concentrations were significantly decreased in septic rats. Both plasma insulin and plasma glucagon concentrations were markedly elevated in response to sepsis. Sepsis resulted in a negative nitrogen balance. 3. Sepsis increased the rates of production of glutamine (52.5%, P less than 0.001), alanine (38.9%, P less than 0.001) and glutamate (48.6%, P less than 0.001) by lung slices incubated in vitro. 4. Sepsis increased lung blood flow by 27.6% (P less than 0.05). Blood flow and arteriovenous concentration difference measurement across the lung of septic rats showed an increase in the net exchange rates of glutamine (142.5%, P less than 0.001), alanine (129.4%, P less than 0.001), glutamate (100.9%, P less than 0.001) and ammonia (138.0%, P less than 0.001) as compared with sham-operated control rats. 5. Sepsis produced significant decreases in the lung concentrations of glutamine (36.8%), glutamate (20.8%), 2-oxoglutarate (64.8%) and AMP (18.3%). The lung concentrations of alanine (95.9%), ammonia (67.7%) and pyruvate (89.7%) were increased. 6. The maximal activities of glutamine synthetase (20.4%, P less than 0.05), phosphate-dependent glutaminase (18.9%, P less than 0.05) and alanine aminotransferase (25.5%, P less than 0.05) were increased, but there was no marked change in that of glutamate dehydrogenase, in the lungs of septic rats.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Glutamine and alanine metabolism in lungs of septic rats. 168 36

In the present study protein synthesis and energy level in liver tissue were studied in bacteremic rats following intravenous infusion of 8 +/- 4 X 10(9) live E. coli bacteria and in control animals receiving a corresponding infusion of sterile saline. For the study of protein synthesis, liver slices were incubated in a medium containing 14C-leucine and incorporation rate of amino acid into protein was determined. Hepatic concentrations of ATP, ADP, and AMP were measured and energy charge (EC) was calculated. Twenty-four hours after infusion of E. coli, hepatic protein synthesis rate was 55% higher than in control animals. Liver weight and hepatic protein content were also increased in bacteremic animals. There were no significant differences in adenine nucleotide levels or EC in liver tissue between control and bacteremic animals. Since impairment of various other liver functions has been reported during sepsis, the present results suggest that hepatic protein synthesis has high priority in this condition.
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PMID:Protein and energy metabolism in liver tissue following intravenous infusion of live E. coli bacteria in rats. 354 30

Various metabolic, cellular, and subcellular alterations in cell function and morphology occur during shock or low-flow conditions. In attempting to find treatment programs that would be beneficial following shock, various substrates have been used. Infusion of hypertonic glucose during shock has been shown to improve survival; however, it is unlikely that the effect of glucose is by provision of energy until the circulation is restored. Infusion of glucose--insulin--potassium during shock has also been reported to be beneficial in certain clinical situations. Controversies exist concerning the efficacy of infusions of cyclic AMP, nicotinamide, and Krebs cycle intermediates during shock. Pretreatment of kidneys with inosine or raising glycogen stores of the myocardium have been shown to have protective effects of kidneys and myocardium during ischemia and these procedures may be suitable for organ preservation. Pretreatment with allopurinol has been shown to be beneficial in shock; however, it is unlikely that allopurinol by itself if given following shock would have any salutary effects. Treatment with ATP-MgCl2 has been shown to be beneficial following hemorrhagic shock, sepsis, endotoxin shock, burns, postischemic hepatic failure, and postischemic renal failure. Thus, provision of energy directly in the form of ATP during adverse circulatory conditions appears to be the most advantageous and direct method for the treatment of shock.
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PMID:The use of substrates and energy in the treatment of shock. 627 59

Changes in muscle high-energy phosphates in varying degrees of resting hypermetabolism were studied. Eleven patients were investigated before and 4 days after total hip replacement. The postoperative results were compared with those seen in major traumas and sepsis. High-energy phosphates were not significantly changed in muscle after total hip replacement or moderate injury; muscle lactate and pyruvate increased. Increased degrees of hypermetabolism such as severe trauma and sepsis were associated with reduction of muscle ATP and PC; AMP, free CR, lactate, and pyruvate rose. Simultaneously determined levels of high-energy phosphates in red blood cells did not reflect muscle changes, confirming the need for continued direct tissue measurements. Alterations in the ATP--ADP--AMP system in the muscle cell suggest a low-energy charge following severe trauma especially if accompanied by sepsis. This would indicate a decreased capcity for biosynthetic reactions and production of storage compounds. Tissue high-energy phosphates and cellular energy levels thus may be the cellular expression of the catabolic state.
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PMID:Effect of injury and sepsis on high-energy phosphates in muscle and red cells. 644

Platelet activating factor (PAF) is an important mediator of pulmonary microvascular endothelial cell (PMVEC) injury in sepsis. Membrane receptors for PAF have been identified on PMVECs and mediate its actions at least in part by protein kinase C activation. Since rolipram, a family IV cyclic AMP phosphodiesterase inhibitor, and isoproterenol, an adenylate cyclase activator, both reverse ischemia-reperfusion-induced lung permeability, we studied the effects of these agents on PAF-induced pulmonary microvascular permeability. The isolated rat lung model was used in which lungs were ventilated and buffer perfused at constant flow while suspended from a force transducer to monitor lung weight along with arterial (P(a)) and venous (Pv) pressures. Control lungs (n = 6) were infused with PAF (40 nmole/kg) via an arterial port and the capillary permeability coefficient (Kf,c) was determined at 0, 15, and 60 min. The remaining lungs were randomized for infusion with either rolipram (n = 4, 20 mumole/kg) or isoproterenol (n = 4, 5 mumole/kg) via an arterial port 30 min after injury with PAF. In the rolipram- and isoproterenol-treated groups, the Kf,c was determined 15 and 60 min postinfusion with these agents. The control group showed significant elevation in the Kf,c and total pulmonary resistance (Rt). At 15 and 60 min, rolipram and isoproterenol reversed PAF injury as shown by the significant improvement in the Kf,c and Rt. These findings support the concept that increased cyclic AMP is an important mediator in the reversal of PAF-increased PMVEC permeability and pulmonary resistance.
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PMID:Rolipram and isoproterenol reverse platelet activating factor-induced increases in pulmonary microvascular permeability and vascular resistance. 763 Jan 21

Sepsis-induced glucose dyshomeostasis has been characterized by an initial hyperglycemia followed by a progressive hypoglycemia. It is well known that the liver plays a predominant role on regulating the homeostatic level of blood glucose. Furthermore, recent studies indicate that protein kinase A, activated by c-AMP, contributes to the role of glycagon in glucogenolysis and glyconeogenesis. Kinetic studies of protein kinase were completed. During late sepsis, in order to further understand the pathophysiology of hepatic glucose disturbances during sepsis. This study investigates the role of protein kinase A in the liver regulating carbohydrate metabolism during early sepsis. The work was performed by using an animal septic model, induced by cecal ligation and puncture (CLP) operation. Through the measurement of blood sugar, a two phase change in sugar level was found. That is, blood sugar significantly increased at 4.5 hrs after CLP operation (p < 0.05) and then significantly decreased at 18 hrs (p < 0.01). In the kinetic studies of protein kinase A, the results showed that, during early sepsis, the activities of both type I (eluted at low ionic strength) and type II (eluted at high ionic strength) protein kinase A were unchanged. Moreover, the kinetic parameters, Vmax and S0.5, of protein kinase A showed no significant difference between two groups. As such, it is suggested that hyperglycemia during early sepsis is not connected to the regulation of protein kinase A.
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PMID:[Kinetic studies of protein kinase A in rat liver during early sepsis]. 849 56

1. This study was designed to investigate the role of rat phosphodiesterase 3 (RPDE3) in regulation of liver metabolism in sepsis. We studied the effects of the phosphodiesterase 3 inhibitor (PDI), enoximone, alone and in combination with regulating factors of hepatic carbohydrate metabolism and bile secretion in the perfused liver of rats treated 4 h earlier with endotoxin. In addition, cyclic AMP and cyclic GMP levels were determined in the effluate and bile by radio immunoassay methods. 2. After endotoxin treatment, infusion of enoximone at three concentrations (1 microM, 10 microM) resulted in an increased glucose output from -1.4 +/- 0.9 to 7.8 +/- 2.5 mumol l-1 20 min-1. Bile acid-independent bile flow increased also, in a dose-dependent manner. 3. In untreated livers, cyclic AMP release increased in the effluate from 1000 +/- 73 fmol g-1 min-1 to 1710 +/- 143 fmol g-1 min-1 when enoximone (10 microM) was administered. In bile from untreated livers, the level of cyclic AMP was also significantly increased by enoximone. After endotoxin treatment, the enoximone (10 microM) effect on cyclic AMP levels in effluate and bile was greatly reduced. Levels of cyclic GMP in the effluate and bile appeared unchanged in the presence of enoximone. 4. During co-infusion of glucagon (1 nM) and enoximone (10 microM), cyclic nucleotide levels in the effluate and bile of livers after endotoxin treatment were determined. In the effluate, cyclic AMP release increased from 827 +/- 144 fmol g-1 min-1 to 17802 +/- 2821 fmol g-1 min-1 when glucagon was administered. The presence of enoximone enhanced cyclic AMP further to 41696 +/- 920 fmol g-1 min-1. The same changes in cyclic AMP release were found in bile. Levels of cyclic GMP in the effluate and bile were not significantly affected by the administration of glucagon and the PDI. 5. Glucose release was determined during glucagon, sympathetic nerves stimulation and phenylephrine administration in the presence and absence of enoximone. The addition of enoximone to glucagon increased glucose release by 8.2 +/- 2.8 mumol g-1 20 min-1, without alteration of lactate balance. The PDI enhanced the glycogenolytic effects of nerve stimulation and of phenylephrine, accompanied by a reduction in lactate production. 6. Enoximone significantly enhanced the bile acid independent bile flow after glucagon, nerves stimulation and after administration of phenylephrine. Bile acid secretion was unaffected by the PDI. The vasoconstrictor effect of nerve stimulation was reduced by the PDI. 7. We conclude that endotoxin treatment reduces the ability of the PDI, enoximone, to increase cyclic AMP release in the perfused liver. The significant increase in cyclic AMP release after stimulation with glucagon and enoximone favours the view that RPDE3 is involved in the degradation of cyclic AMP in the liver after exposure to endotoxin. Additionally, the inhibition of the RPDE3 results in glucose release, vasodilatation and choleresis in endotoxin pretreated livers.
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PMID:Effects of selective phosphodiesterase 3 inhibition in the perfused liver of the rat after endotoxin treatment. 876 9

Adrenomedullin (ADM) is a recently discovered peptide with potent vasorelaxing and natriuretic properties originally isolated from human pheochromocytoma. Adrenomedullin has been reported to be present in normal adrenal medulla, heart, lung and kidney as well as in plasma and urine. ADM shares some structural homology with calcitonin gene related peptide (CGRP). ADM acts on target cells through its unique receptors and CGRP1 receptors. In both cases cyclic AMP seems to be the main second messenger. ADM may function as a circulating hormone and as an autocrine/paracrine mediator involved in the regulation of cardiovascular system and renal function. Plasma concentration of ADM is elevated in patients with congestive heart failure, arterial hypertension, pulmonary hypertension, renal failure and sepsis suggesting its role in pathophysiology of these disorders. Recently another product od adrenomedullin gene, proadrenomedullin N-terminal 20-peptide (PAMP) has been described. This peptide has also vasodilating activity resulting from its inhibitory action on norepinephrine release from sympathetic endings and adrenal medulla.
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PMID:[Adrenomedullin]. 1035 50


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