RESUMO
Diabetes mellitus is associated with changes in intestinal morphology and the enteric nervous system. We previously reported constipation in Goto-Kakizaki (GK) rats, a non-obese model for type 2 diabetes mellitus. AIM: The morpho-quantitative analysis of myenteric plexus neurons in the small and large intestines of 120-day-old male GK rats was investigated. METHODS: The diabetes was confirmed by high fasting blood glucose levels. The myenteric plexus was evaluated through wholemount immunofluorescence. The morpho-quantitative analyses included evaluating neuronal density (neurons per ganglion) of the total neuronal population, the cholinergic and nitrergic subpopulations, and enteric glial cells per ganglion. The cell body area of 100 neurons per segment per animal was measured. RESULTS: The total neurons and nitrergic subpopulation were unaltered in the GK rats' small and large intestines. The cholinergic subpopulation exhibited decreased density in the three segments of the small intestine and an increased number in the proximal colon of the GK rats. The number of enteric glial cells increased in the ileum of the GK rats, which could indicate enteric gliosis caused by the intestinal inflammatory state. The area of the cell body was increased in the total neuronal population of the jejunum and ileum of the GK rats. Frequency histograms of the cell body area distribution revealed the contribution of cholinergic neurons to larger areas in the jejunum and nitrergic neurons in the ileum. CONCLUSION: The constipation previously reported in GK rats might be explained by the decrease in the density of cholinergic neurons in the small intestine of this animal model.
Assuntos
Motilidade Gastrointestinal , Plexo Mientérico , Animais , Plexo Mientérico/patologia , Masculino , Ratos , Neurônios Nitrérgicos/patologia , Neurônios Nitrérgicos/metabolismo , Neuroglia/patologia , Neuroglia/metabolismo , Diabetes Mellitus Tipo 2/patologia , Diabetes Mellitus Tipo 2/fisiopatologia , Neurônios Colinérgicos/patologia , Neurônios Colinérgicos/metabolismo , Neurônios/patologia , Neurônios/metabolismo , Modelos Animais de DoençasRESUMO
Goto-Kakizaki (GK) rats develop a well-defined insulin resistance (IR) and type 2 diabetes mellitus (T2DM) without presenting obesity. The lymphocyte profile in nonobese diabetic conditions is not yet characterized. Therefore, GK rats were chosen to explore T lymphocyte (TL) dynamics at various stages (21, 60, and 120 days) compared to Wistar rats. GK rats exhibit progressive disruption of glucose regulation, with early glucose intolerance at 21 days and reduced insulin sensitivity at 60 days, confirming IR. Glucose transporter 1 (GLUT1) expression was consistently elevated in GK rats, suggesting heightened TL activation. T-regulatory lymphocyte markers diminished at 21 days. However, GK rats showed increased Th1 markers and reduced Gata-3 expression (crucial for Th2 cell differentiation) at 120 days. These findings underscore an early breakdown of anti-inflammatory mechanisms in GK rats, indicating a proinflammatory TL profile that may worsen chronic inflammation in T2DM.
Assuntos
Diabetes Mellitus Tipo 2 , Resistência à Insulina , Ratos Wistar , Animais , Diabetes Mellitus Tipo 2/imunologia , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/patologia , Ratos , Masculino , Inflamação/metabolismo , Inflamação/patologia , Inflamação/imunologia , Fator de Transcrição GATA3/metabolismo , Fator de Transcrição GATA3/genética , Linfócitos T/imunologia , Linfócitos T/metabolismo , Transportador de Glucose Tipo 1/metabolismo , Transportador de Glucose Tipo 1/genética , Células Th1/imunologia , Células Th1/metabolismoRESUMO
Background Glutamine levels directly associate with total protein content in cultured skeletal muscle cells, whereas glutamine supplementation enhances skeletal muscle mass in catabolic experimental conditions. Methods We compared the effect of glutamine administration on Extensor Digitorum Longus muscle (EDL) weight, fiber cross-sectional area (CSA), contractile activity, and protein metabolism signaling with a functional overload-induced skeletal muscle hypertrophy protocol. Results Glutamine supplementation raised the predominance of EDL muscle fibers with CSA between 1001 and 2000 μm2 (49.7 %), the p-4E-BP1/total 4E-BP1 ratio, and the effect of overload on resistance to fatigue. The proportion of the EDL muscle fiber CSA distribution for the combination of both treatments was similar to that induced by overload or glutamine separately; 54.3 % muscle fibers with CSA between 1001 and 2000 μm². Glutamine supplementation did not markedly affect the changes induced by overload on protein synthesis signaling pathways, except for a further increase of the p-4E-BP1/total 4E-BP1 ratio. Conclusions The effect of glutamine on EDL muscle fiber CSA distribution and protein synthesis signaling mimicked the response to overload. The association of glutamine and overload induced EDL muscle hypertrophy further increased the resistance to fatigue.