RESUMO
The aim of the study was to investigate the role of diabetic intrauterine environment on circulating insulin, glucagon, and somatostatin levels in pregnant rats, fetuses, and offspring. Diabetes was induced in female Wistar rats by streptozotocin at birth or as adult and the animals were assigned into: control (C); mildly diabetic (MD); and severely diabetic (SD). The rats were mated and distributed into 2 subgroups: euthanasia at day 21 of pregnancy and at day 10 postpartum. Both MD and SD dams showed impaired oral glucose tolerance. SD dams had lower body weight and insulin levels compared to C and MD dams. SD fetuses presented hyperglycemia and reduction of insulin and glucagon levels compared to C and MD fetuses. SD newborns had diminished total pancreatic insulin and plasma somatostatin compared to the other groups. MD dams and fetuses had lower glucagon and somatostatin levels compared to C dams. MD offspring had maintained lower somatostatin levels to neonatal period. Diabetes causes alterations in circulating levels of pancreatic hormones in the mother and offspring.
Assuntos
Biomarcadores/sangue , Diabetes Mellitus Experimental/fisiopatologia , Glucagon/sangue , Insulina/sangue , Hormônios Pancreáticos/sangue , Somatostatina/sangue , Animais , Animais Recém-Nascidos , Feminino , Gravidez , Ratos , Ratos WistarRESUMO
In sea-level natives, exposure to hypoxia for a few weeks is characterized by an increased dependence on blood glucose and a decreased reliance on lactate for energy metabolism during exercise. These metabolic adjustments have been attributed to behavioral changes in the sympathoadrenergic and pancreatic systems. The aim of this study was to test the hypothesis of a reduced sympathoadrenergic activation and subsequent metabolic changes when high-altitude natives are acutely exposed to normoxia. Young Andean natives performed incremental exercise to exhaustion during hypoxia (arterial PO2 55.1 +/- 1.1 Torr) or during acute normoxia (arterial PO2 78.7 +/- 1.7 Torr). As a whole, oxygen uptake was increased in normoxia compared with hypoxia during graded exercise. This finding is not related to a decrease in anaerobic metabolism but rather is interpreted as a consequence of a shift in substrate utilization during exercise (increased contribution of fat as assessed by a reduction in the respiratory exchange ratio). These metabolic changes are not accompanied by modifications of glucoregulatory hormones (catecholamines, insulin, and glucagon). In particular, the exercise-induced catecholamine secretion was similar in chronic hypoxia and acute normoxia. As a consequence, blood lactate accumulation during incremental exercise was similar in both conditions. It is concluded that high-altitude natives do not display any sign of a greater sympathoadrenergic activation during chronic hypoxia and that the exercise-induced hormonal changes remained unaffected by acute inhalation of a normoxic gas mixture.
Assuntos
Altitude , Exercício Físico/fisiologia , Hormônios/sangue , Hipóxia/metabolismo , Hipóxia/fisiopatologia , Adulto , Gasometria , Glicemia/metabolismo , Sistema Cromafim/metabolismo , Sistema Cromafim/fisiologia , Teste de Esforço , Humanos , Masculino , Consumo de Oxigênio/fisiologia , Hormônios Pancreáticos/sangue , Sistema Nervoso Simpático/metabolismo , Sistema Nervoso Simpático/fisiologiaRESUMO
A liberaçäo dos hormônios gastro êntero pancreáticos foi investigada em dez portadores de Doença de Chagas crónica e os resultados obtidos comparados e analisados estatisticamente com os observados em nove controles. A avaliaçäo hormonal baseou-se na determinaçäo sérica das concentraçöes da gastrina, glucagon pancreático, polipeptídio pancreático, enteroglucagon, motilina e colecistocinina, em condiçöes basais e pelos, estímulos direto (administraçäo venosa de secretina e de ceruleína) e misto (administraçäo venosa de secretina eintra-duodenal de fenilalanina). A liberaçäo dos hormônios gastro-éntero-pancreáticos, em condiçöes basais e pelo estímulo direto, encontra-se preservada nos chagásicos a exceçäo da gastrina, que se apresenta significativamente mais elevada, tanto em condiçöes basais como pelo estímulo pela secretina. A liberaçäo do polipeptídeo pancreático mostrou-se significativamente reduzida nos chagásicos crônicos pelo estímulo com a fenilalanina. As alteraçöes detectadas na resposta hormonal sugerem comprometimento neural do eixo éntero-pancreático nesses pacientes
Assuntos
Adulto , Pessoa de Meia-Idade , Humanos , Masculino , Feminino , Doença de Chagas/fisiopatologia , Hormônios Gastrointestinais/sangue , Hormônios Pancreáticos/sangueRESUMO
The seric levels of gastrin, pancreatic glucagon, pancreatic polypeptide, enteroglucagon, motilin and cholecistokinin were evaluated in ten patients with chronic Chagas' disease and compared with those observed in nine normal control subjects. The seric values of all the hormones were determined on basal stimulation, after continuous intravenous secretin infusion and infusion of stepwise increased concentrations of caerulein (direct stimulation), and after intravenous secretin administration followed by intraduodenal instilation of increased concentrations of phenylalanina (combined stimulation). All the hormones, basal and after direct stimulation, showed similar values, except gastrin that in the chagasic group presented higher levels than in control subjects. Phenylalanine and pancreatic polypeptide showed significantly higher values in the control group than in the one of patients with Chagas' disease. The hormonal response in patients with chronic Chagas' disease suggested a neural impairment of the enteropancreatic axis.
Assuntos
Doença de Chagas/sangue , Hormônios Gastrointestinais/sangue , Hormônios Pancreáticos/sangue , Adolescente , Adulto , Ceruletídeo/farmacologia , Acalasia Esofágica/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fenilalanina/farmacologia , Secretina/farmacologia , Estimulação QuímicaRESUMO
Está amplamente demonstrada a importância dos hormônios pancreáticos, presentes no sangue portal, na manutençäo da integridade anatomofuncional do fígado. O objetivo do presente trabalho foi avaliar a resposta regenerativa do fígado à hepatectomia parcial, correlacionada aos conteúdos hepáticos de lipídios totais e glicogênicos, em cäes diabéticos por pancreatectomia total e por aloxana. Foram estudados 24 cäes mestiços de ambos os sexos, com peso corpóreo variando de 9 a 13 Kg, divididos em três grupos submetidos à hepatectomia parcial: C-controle (n=8), DP - diabéticos por pancreatectomia total (n=8) e DA-diabéticos por aloxana (n=8). O período de observaçäo pós-hepatectomia foi de sete dias. Nos cäes controles, observou-se regeneraçäo hepática sem infiltraçäo significativa de glicogênio e lipídios totais no fígado. Nos cäes diabéticos, observou-se ausência de resposta regenerativa do fígado, de forma mais evidente nos diabéticos por aloxana, grande infiltraçäo hepática lipídica mais intensa nos pancreatectomizados e diminuiçäo semelhante do glicogênio hepático nos dois grupos diabéticos
Assuntos
Cães , Animais , Masculino , Feminino , Diabetes Mellitus Experimental , Hepatectomia , Hormônios Pancreáticos/sangue , Regeneração HepáticaRESUMO
To study the role of enteroinsular hormones in fetal macrosomia and neonatal hypoglycemia in infants of diabetic mothers, we measured plasma concentrations of free and total immunoreactive insulin, C-peptide, pancreatic glucagon, enteroglucagon, and gastric inhibitory polypeptide at birth in 35 IDMs and 35 infants of normal mothers. Twenty fasting adults of normal weight were also studied. Sixteen IDMs were macrosomic at birth; 17 developed neonatal hypoglycemia over the first postnatal hours. The IDMs had ten times higher concentrations of free IRI than the normal infants in cord blood. Free IRI concentrations were related to the severity of maternal diabetes, with the infants of white class D to F mothers having the highest levels. The IDMs with macrosomia had a twofold increase in the concentrations of free IRI when compared with IDMs of normal weight. There was a significant correlation between the birth weight ratio and the concentrations of free IRI. The IDMs who developed neonatal hypoglycemia had considerably higher concentrations of free IRI than did normoglycemic IDMs. The decrease of blood glucose over the first postnatal hours correlated strongly with the free IRI concentrations in the cord blood. The IDMs had a threefold increase of the C-peptide concentrations over those in normal infants. Six IDMs had a molar ratio of C-peptide to free IRI of less than 1. Both the IDMs and normal infants had substantially higher concentrations of enteroglucagon and lower concentrations of GIP than did the fasting adults. Our data provide direct evidence that IDMs are markedly hyperinsulinemic at birth and that ambient hyperinsulinemia plays a crucial role in the development of fetal macrosomia and neonatal hypoglycemia. Moreover, the observed discrepancy in the relative increase of free IRI and C-peptide, combined with the low molar ratio of C-peptide to IRI, suggests a decreased metabolic clearance of insulin or transplacental passage of insulin from the maternal circulation in infants of mothers with insulin-treated diabetes.