RESUMO
Glucose tolerance, insulin secretion, and responses to arginine infusion were studied in 17 adults with severe protein-calorie malnutrition (PCM) in Calcutta, India. Patients were selected for the severity of their malnutrition and for absence of other diseases. After 2-4 mo of refeeding there was complete clinical recovery, and control studies were performed. Glucose tolerance, as assessed by intravenous glucose-tolerance test (IVGTT), was reduced in PCM. Insulin response, both to glucose and to arginine infusion, was clearly reduced. The K value of the IVGTT correlated well with the ratio of mean to basal serum insulin during the first 40 min of the test. Basal serum insulin was nearly unchanged in PCM as compared with after recovery, although one patient studied serially showed a temporary drop in basal insulin during the first week of refeeding. In PCM, plasma amino acid levels failed to fall in response to arginine-induced insulin secretion as they did in the control studies. It appears that insulin secretory response is severely reduced in PCM and that a degree of insulin resistance in relation to body weight is present. These changes result in diminished glucose tolerance and probably in a reduced rate of tissue utilization of amino acids. Such alterations may be of adaptive significance in chronic PCM.
Assuntos
Teste de Tolerância a Glucose , Insulina/sangue , Desnutrição Proteico-Calórica/fisiopatologia , Adulto , Aminoácidos/sangue , Arginina , Feminino , Humanos , Insulina/metabolismo , Resistência à Insulina , Secreção de Insulina , MasculinoAssuntos
Sistema Nervoso Autônomo/fisiologia , Catecolaminas/farmacologia , Jejum , Insulina/metabolismo , Fentolamina/farmacologia , Simpatolíticos/farmacologia , Antagonistas Adrenérgicos alfa/administração & dosagem , Adulto , Sistema Nervoso Autônomo/efeitos dos fármacos , Glicemia/análise , Catecolaminas/urina , Ácidos Graxos/sangue , Teste de Tolerância a Glucose , Hormônio do Crescimento/sangue , Humanos , Hiperinsulinismo/etiologia , Insulina/sangue , Antagonistas da Insulina , Secreção de Insulina , Masculino , Ácido Úrico/sangueAssuntos
Doença de Depósito de Glicogênio Tipo I/metabolismo , Doença de Depósito de Glicogênio/metabolismo , Insulina/metabolismo , Adolescente , Adulto , Arginina/farmacologia , Glicemia/análise , Teste de Tolerância a Glucose , Doença de Depósito de Glicogênio/complicações , Doença de Depósito de Glicogênio Tipo I/complicações , Humanos , Hipoglicemia/etiologia , Insulina/sangue , Secreção de Insulina , Pessoa de Meia-IdadeAssuntos
Acromegalia/fisiopatologia , Insulina/metabolismo , Adolescente , Adulto , Arginina , Glicemia , Carboidratos da Dieta , Proteínas Alimentares , Feminino , Glucose , Teste de Tolerância a Glucose , Humanos , Hiperglicemia , Hiperinsulinismo , Insulina/sangue , Secreção de Insulina , Masculino , Pessoa de Meia-IdadeAssuntos
Hormônio do Crescimento/sangue , Desnutrição Proteico-Calórica/fisiopatologia , Adolescente , Adulto , Aminoácidos/sangue , Arginina/farmacologia , Ingestão de Alimentos , Feminino , Teste de Tolerância a Glucose , Humanos , Sistema Hipotálamo-Hipofisário/fisiopatologia , Masculino , Pessoa de Meia-Idade , Fatores de TempoAssuntos
Ácidos Graxos não Esterificados/sangue , Glucose/metabolismo , Hormônio do Crescimento/sangue , Insulina/sangue , Receptores de Droga , Inanição/metabolismo , Ensaios Clínicos como Assunto , AMP Cíclico/metabolismo , Teste de Tolerância a Glucose , Humanos , Insulina/metabolismo , Secreção de Insulina , Masculino , Fentolamina/farmacologia , Propranolol/farmacologia , Receptores Adrenérgicos/efeitos dos fármacos , Estimulação QuímicaRESUMO
An intertidal site in the Clyde Estuary, UK, was selected to evaluate the role of sediment geochemistry on the bioaccumulation of polychlorinated biphenyls (PCBs) by mussels (Mytilus edulis). The area had previously been identified as showing anomalously high levels of PCB contamination (over 1,500 microg kg(-1) total PCB in sediment, 22 congeners). Samples of surface sediment and M. edulis were collected from two closely located sites, one within the anomalous area and another representing typical PCB contamination in the estuary. Sediment samples were separated into grain size fractions and analysed for a range of biomarker compounds, PCBs and sediment mineralogy. The anomalous site showed an atypical association of PCBs with sediment properties, despite both locations showing influence of both petrogenic and pyrogenic organic contamination. Interrogation of data using correlation and principal component analysis showed that sediment mineralogy as well as organic matter composition influenced PCB congener distribution. One sediment source was found to control the PCB concentration in mussels at both locations and clay mineralogy appears to control PCB uptake by biota with preference for higher molecular weight congeners. Overall bioavailability is determined by sediment TOC.