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1.
Biochim Biophys Acta ; 406(3): 362-9, 1975 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-1182169

RESUMO

The fluorescence properties of chlorophyll a and b monomolecular films at the air-water interface were measured by a high sensitivity fluorophotometer using the photon-counting method. The fluorescence intensity of chlorophyll molecules in monomolecular films in the absence of any diluents did not decrease simply with the mean distance of chlorphyll molecules. Over the range of the mean distances from 27 to 21 A, three fluorescence components (peaks at 685, 695 and 715 nm) of chlorophyll a were observed. In the case of chlorophyll beta, two fluorescence components (peaks at 667 and 685 nm) were observed over the range of the mean distances from 34 to 24 A. When the mean distance was 18 A, the short wavelength component of chlorophyll beta disappeared, and only the long avelength component was observed.


Assuntos
Clorofila , Sítios de Ligação , Membranas Artificiais , Modelos Biológicos , Plantas , Espectrometria de Fluorescência , Propriedades de Superfície
2.
Biochim Biophys Acta ; 1381(2): 265-70, 1998 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-9685674

RESUMO

We have previously demonstrated that the activity of superoxide dismutase (SOD), an antioxidant, is enhanced by low-dose X-ray irradiation in various organs of animals such as rats. Since SOD is an enzyme that mediates the dismutation of O2- to H2O2, the question as to whether the resultant H2O2 is further detoxicated into H2O and O2 or not must still be evaluated. Hence, we studied the effect of low-dose X-ray irradiation on the synthesis of glutathione peroxidase (GSHPx), which is an antioxidant that catalyzes this reaction. The results suggest that H2O2 produced by increased SOD activity can be detoxicated into H2O and O2 due to simultaneous enhancement of the GSHPx activity by X-ray irradiation at 20 cGy, in contrast to irradiation at 400 cGy. The results also show the enhancement in enzyme activities by induction of their synthesis shortly after irradiation at 20 cGy. Moreover, as this phenomenon was observed in BALB/c mice (which are more radiation-sensitive compared to other mouse strains) and radiation-resistant C57BL/6NJcl mice, it was considered to be a common phenomenon in the rat spleen.


Assuntos
Glutationa Peroxidase/biossíntese , Baço/enzimologia , Baço/efeitos da radiação , Superóxido Dismutase/biossíntese , Animais , Relação Dose-Resposta à Radiação , Indução Enzimática/efeitos da radiação , Glutationa Peroxidase/genética , Peróxido de Hidrogênio/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Tolerância a Radiação , Ratos , Especificidade da Espécie
3.
Int J Dev Biol ; 41(4): 569-73, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9303344

RESUMO

The expression of tenascin gene during murine mammary gland development was analyzed by in situ hybridization with non-radioactive cRNA probes. The aim was to identify whether cells that synthesize tenascin are mesenchymal or epithelial. During embryogenesis, tenascin mRNAs were demonstrated in the epithelial cells of the mammary bud on the 14th and 15th day of gestation, and in the mesenchymal cells from the 14th day to the 17th day, at the epithelial-mesenchymal border of the growing bud. However, cells displaying tenascin mRNAs were not found beyond the bifurcation of the mammary sprout at the beginning of the branching morphogenesis. In post-natal development, tenascin mRNAs were demonstrated in mesenchymal cells surrounding end buds in juvenile mice, in mesenchymal cells surrounding the epithelial cells of plaques, in epithelial cells of the lactating mammary gland, in malignant epithelial cells and in the mesenchymal cells surrounding cancer nests. By immunohistochemistry, tenascin immunoreactivity was shown to have the same spatiotemporal distribution as that of tenascin mRNAs, but was observed to be restricted to the stroma, except in the lactating mammary gland where tenascin was demonstrated in the milk by Western blot. The present study thus showed that both epithelial and mesenchymal cells are sources of tenascin at different stages of murine mammary gland development.


Assuntos
Expressão Gênica , Glândulas Mamárias Animais/crescimento & desenvolvimento , Glândulas Mamárias Animais/metabolismo , Neoplasias Mamárias Animais/genética , Tenascina/genética , Animais , Western Blotting , Diferenciação Celular , Epitélio/metabolismo , Feminino , Imuno-Histoquímica , Hibridização In Situ , Lactação/fisiologia , Glândulas Mamárias Animais/citologia , Glândulas Mamárias Animais/embriologia , Neoplasias Mamárias Animais/metabolismo , Mesoderma/metabolismo , Camundongos , Camundongos Endogâmicos , Morfogênese , RNA Complementar/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Tenascina/biossíntese
4.
J Biochem ; 119(4): 703-10, 1996 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8743572

RESUMO

To elucidate the role of a flexible loop (residues 64-72) in the stability and function of Escherichia coli dihydrofolate reductase, glycine-67 in this loop was substituted by site-directed mutagenesis with seven amino acids (Ala, Cys, Asp, Leu, Ser, Thr, and Val). The circular dichroism spectra suggested that the confirmation of the native structure was affected by the mutations in both the presence and absence of NADPH. The free energy change of unfolding by urea decreased in the order of G67A > G67S > or = wild-type > or = G67D > G67T > G67C > or = G67L > G67V. The steady-state kinetic parameters for the enzyme reaction, Km and kcat, were only slightly influenced, but the rate of the hydride transfer reaction was significantly changed by the mutations, as revealed by the deuterium isotope effect on the enzyme activity. These results suggest that site 67 in the flexible loop, being very far from the active site, plays an important role in the stability and function of this enzyme. The characteristics of the mutations were discussed in terms of the modified flexibility of the native structure, compared with the results of mutations at site 121 in another flexible loop.


Assuntos
Escherichia coli/enzimologia , Glicina/fisiologia , Mutação Puntual , Tetra-Hidrofolato Desidrogenase/química , Tetra-Hidrofolato Desidrogenase/metabolismo , Sequência de Bases , Dicroísmo Circular , Estabilidade Enzimática , Cinética , Modelos Moleculares , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Conformação Proteica , Desnaturação Proteica , Tetra-Hidrofolato Desidrogenase/genética , Termodinâmica , Ureia
5.
J Biochem ; 123(1): 33-41, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9504406

RESUMO

The structure, stability, and enzymatic function of dihydrofolate reductase (DHFR) from Escherichia coli are influenced by point mutations at sites 67 and 121 in two flexible loops [Gekko et al. (1994) J. Biochem. 116, 34-41; Ohmae et al. (1996) J. Biochem. 119, 703-710]. In the present study, eight double mutants at sites 67 and 121 (G67V/G121S, G67V/G121A, G67V/G121C, G67V/G121D, G67V/G121V, G67V/G121H, G67V/G121L, and G67V/G121Y) were constructed in order to identify interactions between the two sites of DHFR. The far-ultraviolet circular dichroism spectra of double mutants were clearly different from those of the respective single mutants, with significant changes being observed for three mutants, G67V/G121A, G67V/G121L, and G67V/G121S. The Gibbs free energy change of urea unfolding of double mutants could not be expressed by the sum of those of the respective single mutants except for G67V/G121H. The steady-state kinetic experiments showed that the effect of double mutations manifests itself not in Km but in k(cat), and the transition-state stabilization energy for G67V/G121A, G67V/G121C, and G67V/G121L is not equal to the sum of those for the single mutants. These results indicate that the additivity rule essentially does not hold for these double mutants, and that long-range interactions occur between sites 67 and 121, even though they are separated by 27.7 A. This is evidence that the flexible loops play important roles in the stability and function of this enzyme through structural perturbations, in which a small alteration in local atomic packing due to amino acid substitution is cooperatively magnified over almost the whole molecule.


Assuntos
Escherichia coli/enzimologia , Glicina/metabolismo , Mutação , Tetra-Hidrofolato Desidrogenase/metabolismo , Dicroísmo Circular , Estabilidade Enzimática , Escherichia coli/genética , Glicina/genética , Cinética , Conformação Proteica , Dobramento de Proteína , Relação Estrutura-Atividade , Tetra-Hidrofolato Desidrogenase/química , Tetra-Hidrofolato Desidrogenase/genética , Termodinâmica
6.
Radiat Res ; 149(1): 103-6, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9421160

RESUMO

The appearance of prostaglandins and thromboxane in mouse serum after X irradiation was observed by simultaneous quantitative analysis using gas chromatography/mass spectrometry/selected ion monitoring with stable isotope dilution methods. Mice of two strains (C57BL/CN Jcl and BALB/c) showed similar responses to X irradiation. In C57BL/6N Jcl mice, 0.2 Gy irradiation elicited a significant increase in generation of prostanoids: Immediately after irradiation, the 6-keto PGF1 alpha:TXB2 ratio and the level of PGE2 increased, after 20 min 6-keto PGF1 alpha and PGE2 increased, and after 4 h PGE1 and PGE2 increased. In BALB/c mice, generation of prostanoids was increased significantly immediately after irradiation (6-keto PGF1 alpha, 6-keto PGF1 alpha:TXB2 ratio, PGE2), and the increase was maintained from 20 min to 4 h (PGE1, PGE2) after 0.2 Gy irradiation. In C57BL/6N Jcl mice, a significant increase in production of 9alpha,11beta-PGF2 was observed at 20 min after irradiation. In BALB/c mice, a significant increase in 9alpha,11beta-PGF2 was seen immediately after irradiation and was maintained for 20 min. In C57BL/6N Jcl mice, the level of 8-epi PGF2 alpha was clearly increased 4 h after 4 Gy irradiation. A slight and slow increase was also seen after 0.2 Gy irradiation. In BALB/c mice, 8-epi PGF2 alpha was increased significantly at 20 min and 4 h after 4 Gy irradiation. These results show that 0.2 Gy irradiation stimulates production of prostanoids related to the inflammatory response in mice.


Assuntos
Prostaglandinas/sangue , Tromboxanos/sangue , Animais , Relação Dose-Resposta à Radiação , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Raios X
7.
Surgery ; 119(5): 505-10, 1996 May.
Artigo em Inglês | MEDLINE | ID: mdl-8619204

RESUMO

BACKGROUND: Hepatocyte growth factor (HGF) plays a key role in the regulation of liver regeneration after hepatocyte damage. Changes in HGF production reflect the status of the regeneration process. METHODS: Serum concentrations of HGF and energy substrates were measured during and after liver transplantation in 30 recipients. RESULTS: In the patients with compromised grafts (group A) HGF concentrations were persistently high after reperfusion, whereas in the patients with well-functioning grafts (group B), HGF concentrations decreased rapidly and remained low 4 hours after reperfusion. The patients in group A who died had persistently high concentrations of HGF. The surviving patients with reversible primary graft dysfunction in group A exhibited low concentrations 48 hours after reperfusion. The decrease in HGF concentration preceded the decrease in aspartate aminotransferase concentration. The metabolic parameters that reflect carbohydrate metabolism by the graft paralleled the changes in HGF. CONCLUSIONS: HGF may be more sensitive and specific in predicting early graft function than prothrombin time, ratio, aspartate aminotransferase, or arterial ketone body ratio. The determination of HGF levels after liver transplantation may yield valuable information for evaluating early graft function and making an early decision to repeat a graft procedure in an acutely ill patient.


Assuntos
Fator de Crescimento de Hepatócito/sangue , Transplante de Fígado , Adolescente , Adulto , Idoso , Aspartato Aminotransferases/metabolismo , Feminino , Humanos , Lactatos/metabolismo , Ácido Láctico , Fígado/fisiopatologia , Circulação Hepática , Masculino , Pessoa de Meia-Idade , Concentração Osmolar , Período Pós-Operatório , Piruvatos/metabolismo , Ácido Pirúvico , Reperfusão , Análise de Sobrevida
8.
Arch Surg ; 124(3): 309-11, 1989 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-2919964

RESUMO

This study was undertaken to elucidate those histological and gross features associated with gastric carcinoma that can be adequately treated by gastrectomy with less aggressive lymphadenectomy. The frequency of metastasis to the lymph nodes was analyzed in 514 cases of resected, solitary, gastric carcinomas. The frequency of metastasis to the lymph nodes increased in proportion to the increase in the extent of penetration by the cancer into the gastric wall. Lymph nodes were not involved in cases of intramucosal carcinoma of the intestinal type, by Laurén's histological classification. By contrast, metastasis to the lymph nodes was observed in cases of intramucosal carcinoma of the diffuse type, by Laurén's classification. We conclude that extensive lymphadenectomy is not mandatory for patients with intramucosal carcinoma of the stomach of the protruded type, since the lymph nodes do not become involved in this type of gastric carcinoma.


Assuntos
Adenocarcinoma/cirurgia , Excisão de Linfonodo , Neoplasias Gástricas/cirurgia , Adenocarcinoma/classificação , Adenocarcinoma/patologia , Adulto , Feminino , Mucosa Gástrica , Humanos , Metástase Linfática , Pessoa de Meia-Idade , Invasividade Neoplásica , Prognóstico , Neoplasias Gástricas/classificação , Neoplasias Gástricas/patologia
9.
Arch Surg ; 132(2): 136-41, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9041915

RESUMO

BACKGROUND: Excessive blood transfusion during orthotopic liver transplantation (OLT) is correlated with a lower graft survival rate. Experimentally, excessive hemorrhage is associated with endotoxemia and release of proinflammatory cytokines. OBJECTIVES: To measure the concentrations of plasma endotoxin and proinflammatory cytokines during OLT and to investigate their relation to intraoperative blood loss and graft viability. DESIGN AND SETTING: A prospective case series in a liver transplantation center. PATIENTS: Thirty patients who underwent OLT. Group 1 comprised 6 patients whose operative blood transfusion requirement was 10 U or more; group 2 comprised 24 patients whose operative blood transfusion requirement was less than 10 U. INTERVENTIONS: The following factors were measured in the plasma before and after OLT: interleukin (IL)-1 beta, IL-6, tumor necrosis factor alpha, hepatocyte growth factor, endotoxin, hyaluronic acid, and lactate. MAIN OUTCOME MEASURE: Graft viability. RESULTS: Two patients in group 1 died. All 24 patients in group 2 survived after they underwent OLT. The responses of IL-6 and IL-1 beta in group 1 were striking compared with those in group 2, and they were accompanied by an elevation of the endotoxin concentration and a subsequent elevation of the concentrations of hepatocyte growth factor, hyaluronic acid, lactate, and other factors that reflected graft viability. CONCLUSIONS: The changes in IL-6 seemed to respond to the excessive intraoperative hemorrhage, to provoke the elevation of the endotoxin concentration, and to be associated with the graft viability. The prevention of excessive intraoperative bleeding and the subsequent response of proinflammatory cytokines may be contributing factors to the success of liver transplant surgery.


Assuntos
Perda Sanguínea Cirúrgica , Citocinas/sangue , Endotoxinas/sangue , Transplante de Fígado/fisiologia , Adolescente , Adulto , Idoso , Transfusão de Sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
10.
Brain Res ; 499(2): 367-70, 1989 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-2804684

RESUMO

Uric acid (UA) in the rat brain was measured by HPLC with an electrochemical detector following focal ischemia. At 24 h after the operation, the UA level in the ischemic center was 105.47 +/- 8.39 nmol/g tissue, whereas it was 8.36 +/- 1.86 in the sham-operated group. Allopurinol, xanthine oxidase inhibitor, almost completely inhibited this UA accumulation. These data demonstrate that the UA increase in the ischemic brain is due to the xanthine oxidase reaction.


Assuntos
Alopurinol/farmacologia , Isquemia Encefálica/metabolismo , Encéfalo/metabolismo , Ácido Úrico/metabolismo , Animais , Encéfalo/efeitos dos fármacos , Masculino , Ratos , Ratos Endogâmicos
11.
Nutrition ; 6(2): 143-5, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2134526

RESUMO

Our earlier studies in vivo revealed that artificial lipid particles (exo TG) in lipid emulsion acquire apolipoprotein C-II (apo C-II) from high density lipoprotein (HDL). Since the transfer of apo C-II to exo TG terminated within a short time after the intravenous injection of exo TG, it is likely that exo TG has a high affinity for apolipoprotein. This hypothesis has been investigated in vitro. Human plasma was incubated at 37 degrees C with or without a 10% emulsion of soybean oil for 5 min and 60 min. After the incubation, the plasma was separated into HDL, low density lipoprotein (LDL) and very low density lipoprotein (VLDL). Levels of apo C-II, C-III and E in each lipoprotein fraction were quantified. When the plasma was incubated without exo TG, the distribution of apo C-II and C-III in the lipoprotein fractions was unchanged after incubations for 5 and 60 min. However, when the plasma was incubated with exo TG, apo C-II and C-III in the HDL fraction decreased after a 5 min incubation, while those in the VLDL fraction increased. Apo E in each lipoprotein fraction did not change after 5- and 60-min incubations regardless of the presence or absence of exo TG.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Apolipoproteínas/metabolismo , Emulsões Gordurosas Intravenosas/metabolismo , Adulto , Apolipoproteína C-II , Apolipoproteína C-III , Apolipoproteínas/sangue , Apolipoproteínas C/sangue , Apolipoproteínas C/metabolismo , Apolipoproteínas E/sangue , Apolipoproteínas E/metabolismo , Humanos , Técnicas In Vitro , Lipoproteínas/sangue , Masculino , Pessoa de Meia-Idade , Triglicerídeos/metabolismo
12.
Nutrition ; 10(3): 252-4, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7919678

RESUMO

Triacylglycerol (TG)-rich particles in parenteral lipid emulsion have been designed to mimic chylomicrons (CMs), which are exogenous dietary TG-rich lipoproteins. Over the past 30 yr, since lipid emulsions were first used for parenteral nutrition, it has been generally accepted that the intravascular metabolism of TG-rich particles in an emulsion is similar to that of CMs. Both the particles in an emulsion and CMs have a TG core that is stabilized by a surface layer of phospholipids. However, there are major differences between the two types of particles regarding their composition of protein moieties. CMs contain and acquire apolipoproteins, which are essential for the regulation of their intravascular metabolism. In contrast, the TG-rich particles in an emulsion do not contain any apolipoprotein. It has been demonstrated that the particles in an emulsion also acquire various kinds of apolipoprotein during their brief intravascular life. Thus, they may be subject to intravascular metabolic processes similar to those of CMs. In this review, we describe the mechanism by which TG-rich particles in an emulsion acquire apolipoproteins from the perspective of parenteral nutrition with lipid emulsions.


Assuntos
Apolipoproteínas/metabolismo , Emulsões Gordurosas Intravenosas/metabolismo , Lipoproteínas/sangue , Triglicerídeos/metabolismo , Animais , Quilomícrons/metabolismo , Humanos , Microesferas , Triglicerídeos/sangue , Triglicerídeos/química
13.
Nutrition ; 7(5): 355-7, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1804473

RESUMO

Acquisition of apolipoproteins C-II (apoCII) and C-III (apoCIII) is essential for the regulation of intravascular metabolism of fat particles (exoTG). This study was undertaken to investigate whether the capacity of high-density lipoprotein (HDL) for donating apoCII and apoCIII is influenced by the concentration of triglycerides (TGs) in plasma. A fat emulsion was infused into six male volunteers at a rate of 0.5 g TG.kg-1.h-1 (priming dose) for 30 min. For the following 160 min, fat was infused a fat emulsion was infused into the same subjects at a rate of 0.3 g.kg-1.h-1 for 160 min after the administration of the priming dose of fat emulsion for 30 min (experiment 2). The plasma TG concentrations and the amounts of apoCII and apoCIII in exo TG and HDL were monitored. The concentration of TG in the plasma stabilized at approximately 500 mg/dl in experiment 1, whereas it continued to increase to 815 +/- 42 mg/dl at 160 min after the start of the infusion of the fat emulsion in experiment 2. In experiment 1, the amount of both apoCII and apoCIII began to increase in exoTG and to decrease in HDL after the initiation of fat infusion. These changes in the distribution of apoC stabilized while the TG concentration remained at a plateau value. However, in experiment 2, the amount of apoC in exoTG did not increase further in response to the additional rise in plasma TG level. These results suggest that there is a relative lack of apoC that can be donated by HDL, depending on the quantitative balance between exoTG and HDL.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Apolipoproteínas C/sangue , Emulsões Gordurosas Intravenosas/farmacologia , Lipoproteínas HDL/sangue , Triglicerídeos/sangue , Adulto , Apolipoproteína C-II , Apolipoproteína C-III , Humanos , Masculino , Pessoa de Meia-Idade
14.
Nutrition ; 12(2): 79-82, 1996 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8724376

RESUMO

The elimination rate of emulsion triglyceride (TG) from plasma was investigated in Japanese subjects by a plasma TG clamp technique. Two different studies were performed. In Study 1, a lipid emulsion (20% long-chain triglyceride emulsion: LCT) was infused into a healthy research associate to achieve a certain concentration of TG in the plasma. Thereafter, the infusion rate was adjusted to maintain the chosen concentrations of TG in plasma (namely, 4-5 mmol/L, 3-4 mmol/L, and approximately 2 mmol/L) over a period of 160 min by measuring plasma TG concentrations at 10-min intervals. Concentrations of TG in plasma were clamped within 2.13 +/- 0.13 mmol/L by an infusion rate of 0.10 g.kg-1.h-1, within 3.34 +/- 0.20 mmol/L by an infusion rate of 0.14 g.kg-1.h-1, and within 4.46 +/- 0.22 mmol/L by an infusion rate of 0.11 g.kg-1.h-1. The mean rate of infusion of emulsified TG that had maintained the steady concentrations of TG in plasma was limited to the very narrow range of 0.12 +/- 0.02 g of TG.kg-1.h-1 regardless of the chosen concentration of TG in plasma. Concentrations of nonesterified fatty acids (NEFA) also remained at a fixed level of 1.378 +/- 0.103 mEq/L regardless of the chosen concentration of TG in the plasma. Study 2 was undertaken to determine whether plasma TG concentration reached a plateau during a period when emulsion TG was infused into three different subjects at a rate of 0.12 g.kg-1.h-1. The plasma TG concentrations were steady at a level of 2.04 +/- 0.32 mmol/L, and the plasma NEFA concentrations remained at a fixed level of 1.33 +/- 0.13 mEq/L, over a period of 160 min after 50-min priming infusion. These results indicate that the plasma TG elimination rate was limited to the narrow range of 0.12 +/- 0.02 g.kg-1.h-1 when the fat emulsion was infused into Japanese subjects in a steady state. However, the plasma TG elimination rate in Japanese subjects appeared to be lower than that of Europeans. This may be due to a difference in lipoprotein lipase activity caused by different dietary habits, namely, a lower fat intake.


Assuntos
Emulsões Gordurosas Intravenosas/farmacocinética , Triglicerídeos/sangue , Adulto , Ácidos Graxos não Esterificados/sangue , Técnica Clamp de Glucose , Humanos , Japão , Cinética , Masculino , Pessoa de Meia-Idade
15.
JPEN J Parenter Enteral Nutr ; 14(4): 381-5, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2119445

RESUMO

Recent studies on the metabolism of artificial lipid particles in a fat emulsion (exo TG) revealed that exo TG acquired apolipoproteins in vivo and in vitro. In particular, apolipoproteins C-II and C-III (apo C-II and apo C-III) are rapidly transferred from high-density lipoprotein (HDL) to exo TG, and return to HDL after the hydrolysis of exo TG. The present study was undertaken to examine whether the movement of apo C-II and apo C-III between HDL and exo TG is influenced by a prior injection of fat emulsion. Two experiments were undertaken. In experiment 1, six male volunteers received three bolus injections of a fat emulsion at a dose of 0.1 g of TG/kg with intervals of 90 min between injections. In experiment 2, the plasma concentrations of triglycerides were maintained at approximately 500 mg/dl for 160 min by the continuous infusion of exo TG. Levels of apo C-II and apo C-III, and the elimination rate of exo TG were followed in each test. In experiment 1, the movement of apolipoproteins between exo TG and HDL was unchanged between the first, second, and third bolus. The elimination rate of exo TG after the third bolus was higher than that after the first bolus. In experiment 2, after the administration of exo TG, the levels of C apolipoproteins in the fraction of HDL began to decrease, and those in the fraction of very-low-density lipoprotein that contained exo TG began to increase. When the concentrations of triglycerides in plasma reached a plateau, the distribution of C apolipoproteins in the lipoprotein fraction also stabilized.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Apolipoproteínas/metabolismo , Emulsões Gordurosas Intravenosas/farmacocinética , Lipoproteínas/sangue , Adulto , Apolipoproteína C-II , Apolipoproteína C-III , Apolipoproteínas/sangue , Apolipoproteínas C/sangue , Apolipoproteínas C/metabolismo , Transporte Biológico Ativo , Humanos , Infusões Parenterais/métodos , Lipoproteínas/metabolismo , Lipoproteínas HDL/sangue , Lipoproteínas HDL/metabolismo , Masculino , Pessoa de Meia-Idade , Nutrição Parenteral Total/métodos , Triglicerídeos/sangue , Triglicerídeos/metabolismo
16.
JPEN J Parenter Enteral Nutr ; 6(5): 416-20, 1982.
Artigo em Inglês | MEDLINE | ID: mdl-6818369

RESUMO

Changes of serum zinc level in dogs receiving either a zinc-free solution or a zinc-supplement solution during total parenteral nutrition (TPN) and the influence of variety of serum-zinc level on serum albumin and collagen-hydroxyproline (C-Hyp) in the incised intestine were investigated. The serum zinc level of zinc-free dogs that was 126.0 +/- 34.3 micrograms per deciliter at the initiation of TPN decreased significantly to 80.0 +/- 15.0 micrograms per deciliter during the one week of TPN, whereas that of zinc-supplement dogs did not decrease during the same period of TPN. Lowering of the serum albumin value was more evident in zinc-free dogs than in zinc-supplement dogs. The amount of C-Hyp in the incised area of the intestine of zinc-free dogs was 2.63 +/- 0.66 micrograms per milligram and that of zinc-supplement dogs was 4.26 +/- 1.04 micrograms per milligram and this difference was significant. It was found that serum zinc level during TPN sharply reflects a supplement of zinc, and C-Hyp in the incised gut and serum albumin of zinc-free dogs are lower than those of zinc-supplement dogs.


Assuntos
Colágeno/metabolismo , Hidroxiprolina/metabolismo , Íleo/fisiologia , Nutrição Parenteral Total , Nutrição Parenteral , Cicatrização , Zinco/sangue , Animais , Cães , Albumina Sérica/metabolismo , Zinco/uso terapêutico
17.
JPEN J Parenter Enteral Nutr ; 8(4): 412-5, 1984.
Artigo em Inglês | MEDLINE | ID: mdl-6431131

RESUMO

An experiment was undertaken to investigate the effects of a continuous infusion of catecholamines on glucose and fat metabolism as well as on nitrogen balance and the amount of triglycerides in the rat liver. The animals were nourished by total parenteral nutrition for 5 days and divided into six groups (n = 5 in each group) on the basis of nonprotein calories given with or without an infusion of catecholamines: group G received 100% of nonprotein calories with glucose, group F received 50% of nonprotein calories with glucose, and the remaining 50% with lipid emulsion, groups Epi-G and Epi-F received epinephrine (1 microgram/kg body weight/min) in addition to the same total parenteral nutrition solution as group G or F, and groups Nor-G and Nor-F received norepinephrine (1 microgram/kg/min) in a similar manner. Each group was administered the same number of total calories (252 cal/kg/day) and the same amount of nitrogen (1.49 g/kg/day). Nitrogen balance was better in group G than in group F. Under catecholamine infusion, there were no significant differences in nitrogen balance between groups Epi-G, Nor-G, Epi-F, and Nor-F, but this parameter improved significantly in group Nor-F in comparison to group F. Liver triglycerides was higher in groups Epi-G and Nor-G than in groups Epi-F and Nor-F. Liver triglycerides was directly related to the blood sugar level. These results indicate that nitrogen conservation is improved with lipid emulsion and that glucose rather than lipid plays a significant role in the genesis of fatty liver, when they are administered under catecholamine-induced stress.


Assuntos
Epinefrina/farmacologia , Glucose/metabolismo , Metabolismo dos Lipídeos , Fígado/metabolismo , Norepinefrina/farmacologia , Nutrição Parenteral Total , Nutrição Parenteral , Triglicerídeos/metabolismo , Animais , Glicemia/metabolismo , Emulsões Gordurosas Intravenosas , Ácidos Graxos/metabolismo , Fígado/efeitos dos fármacos , Masculino , Nitrogênio/metabolismo , Ratos , Ratos Endogâmicos
18.
JPEN J Parenter Enteral Nutr ; 8(4): 440-2, 1984.
Artigo em Inglês | MEDLINE | ID: mdl-6379218

RESUMO

The effect of endotoxemia on the initial catabolism of intravenously given lipid emulsion was investigated in dogs. Two types of endotoxemia were prepared. One was produced by peritonitis which was established by ligation of the artery and vein of an isolated intestine (group 1, n = 6). The other was made by an intravenous injection of Escherichia coli lipopolysaccharide in a dose of 1.5 mg/kg of body weight (group 2, n = 6). Group 1 showed evident peritonitis with a positive limulus test 48 hr after the procedure, but no significant changes of blood sugar level and lactate/pyruvate ratio, while group 2 demonstrated profound hypoglycemia, significant elevation of lactate/pyruvate ratio, and low arterial pressure 3 to 5 hr after the injection of lipopolysaccharide. The clearance rate of intravenously administered lipid emulsion (K value) of group 1 before the peritonitis was 0.0105 +/- 0.0017 and after the peritonitis it was 0.0105 +/- 0.0019. The difference was not significant, while the K value of group 2 which was 0.0133 +/- 0.0056 before the injection of lipopolysaccharide decreased significantly to 0.0069 +/- 0.0024 after the injection of lipopolysaccharide. These results suggest that, in case of endotoxemia with normally maintained oxidation-reduction potential, the initial catabolism of intravenously given lipid emulsion is kept in a normal level, while oxidation-reduction potential is impaired, it is inhibited.


Assuntos
Endotoxinas/sangue , Escherichia coli , Emulsões Gordurosas Intravenosas/metabolismo , Choque Séptico/metabolismo , Animais , Glicemia/análise , Cães , Ácidos Graxos não Esterificados/sangue , Feminino , Lactatos/sangue , Ácido Láctico , Masculino , Oxirredução , Piruvatos/sangue , Ácido Pirúvico
19.
JPEN J Parenter Enteral Nutr ; 17(1): 77-81, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8437330

RESUMO

This preliminary study was undertaken to ascertain whether our newly developed model of the cold ischemic rat liver in situ is applicable to studies designed to assess the metabolism of nutrients. Ischemia of the whole liver of 12 Wistar rats was induced by clamping all supply and drainage vessels. The ischemic liver was perfused in situ. The duration of ischemia of the liver was 20 minutes. Saline was infused into six rats throughout the experiment (group A). An intravenous infusion of glucose at a rate of 0.75 g/h per rat was begun immediately after the induction of blood-reflow to the liver (group B, n = 6). Six rats (group C) did not undergo the procedure for induction of hepatic ischemia and received glucose at the same rate as rats in group B. Changes in hepatic levels of sugar phosphates (phosphomonoesters [PMEs]), inorganic phosphorus, and beta-positioned phosphorus in adenosine triphosphate (beta-ATP) were monitored by 31P magnetic resonance spectroscopy. Ischemia caused a significant increase in levels of PMEs and a decrease in levels of beta-ATP. The infusion of glucose caused a further increase in levels of PMEs and a further decrease in levels of beta-ATP in group B. In contrast, in group C such infusion did not induce any changes in levels of PMEs or beta-ATP. In group A, PMEs and beta-ATP returned to basal levels 5 hours after the induction of blood-reflow to the liver. The changes in levels of PMEs were similar to those in levels of inorganic phosphorus in all groups.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Trifosfato de Adenosina/metabolismo , Glucose/farmacologia , Isquemia/metabolismo , Fígado/metabolismo , Fosfatos Açúcares/metabolismo , Animais , Glucose/administração & dosagem , Infusões Intravenosas , Fígado/irrigação sanguínea , Transplante de Fígado/fisiologia , Espectroscopia de Ressonância Magnética , Masculino , Modelos Biológicos , Perfusão , Ratos , Ratos Wistar
20.
JPEN J Parenter Enteral Nutr ; 10(4): 413-5, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-3091866

RESUMO

The effects of parenteral nutrition (PN) and of the difference in the PN regimens between glucose and lipid emulsion on the development of endogenous endotoxemia were studied in 40 Wister rats. Endotoxemia was induced by occluding the superior mesenteric vein (SMV) for 30 min. The plasma endotoxin in the portal blood at the time of the release of the SMV occlusion and that in the arterial blood 10 min after the release were quantified. Twenty of the 40 rats had received PN for 48 hr prior to the SMV occlusion. Ten of these 20 rats received the total nonprotein calorie (TNPC) solely with glucose, and the other 10 rats received 25% of the TNPC with lipid emulsion. Ten rats had been allowed free access to lab food until the SMV occlusion. The remaining 10 rats underwent neither the SMV occlusion nor PN, and served as the control group. Both the portal and the arterial endotoxin increased after the release of the SMV occlusion, however the portal endotoxin was higher than that of the arterial one. Both the portal and the arterial endotoxin of the rats supported by PN were significantly lower than those of the rats nourished by lab food, while they were higher than the control values. The difference in the PN regimens did not cause any alteration in the endotoxin levels. These results indicate that the development of intestinal endotoxemia was not influenced by the difference in the PN regimens, but it was rather influenced by a presence of intestinal content.


Assuntos
Endotoxinas/sangue , Emulsões Gordurosas Intravenosas/farmacologia , Glucose/farmacologia , Enteropatias/prevenção & controle , Nutrição Parenteral Total , Animais , Endotoxinas/biossíntese , Masculino , Veias Mesentéricas , Fagocitose/efeitos dos fármacos , Ratos , Ratos Endogâmicos
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