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The prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH) is increasing, and translational animal models are needed to develop novel treatments for this disease. The physiology and metabolism of pigs have a relatively high resemblance to humans, and the present study aimed to characterise choline-deficient, and high-fat diet (CDAHFD) fed Göttingen Minipigs as a novel animal model of MASLD/MASH. Göttingen Minipigs were fed CDAHFD for up to 5 months, and the phenotype was investigated by analysis of plasma parameters and repeated collection of liver biopsies. Furthermore, changes in hepatic gene expression during the experiment were explored by RNA sequencing. For a subset of the minipigs, the diet was changed from CDAHFD back to chow to investigate if the liver pathology was reversible. Göttingen Minipigs on CDAHFD gained bodyweight, and plasma levels of cholesterol, AST, ALT, ALP and GGT were increased. CDAHFD-fed minipigs developed hepatic steatosis, inflammation, and fibrosis, which in 5 of 16 animals progressed to cirrhosis. During an 11-week chow reversal period, steatosis regressed while fibrosis persisted. Regarding inflammation, the findings were less clear, depending on the type of readout. MASH Human Proximity Scoring (combined evaluation of transcriptional, phenotypic and histopathological parameters) showed that CDAHFD-fed Göttingen Minipigs resemble human MASLD/MASH better than most rodent models. In conclusion, CDAHFD-fed minipigs develop a MASH-like phenotype which in several aspects resemble the changes observed in human patients with MASLD/MASH. Furthermore, repeated collection of liver biopsies allow detailed characterisation of histopathological changes over time in individual animals.
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AIMS: To investigate the influence of the dose in the FITC-Dextran 4kDa (FD-4) permeability test in an obese mouse model, we tested the bodyweight dose regimen and a lean body mass-based dose regimen in high fat diet (HFD) mice and low fat diet (LFD) mice. We hypothesized that the FD-4 permeation result would be dose-dependent. METHODS: The two dose regimens were compared in HFD and LFD mice. Furthermore, we conducted a dose-response study to test the effect of a low or high dose of FD-4 in weight-stratified lean mice. Gene analysis of tight junctions was also carried out. RESULTS: The FD-4 intestinal permeability test was dose-dependent as we found a significant increase in plasma levels of FD-4 in obese mice with the bodyweight dose regimen. However, this difference was not detectable with the lean body mass dose regimen, even with variability-adjusted group sizes. However, the qPCR analysis revealed a decrease in tight junction gene expression in obese mice. Furthermore, we found a dose-dependent significant increase in FD-4 measured in plasma samples in lean mice. No significant difference in intestinal weight was observed between lean and obese mice. CONCLUSION: Evaluation of the intestinal permeability by FD-4 with the typical bodyweight dose regimen in obese mice will be confounded by the significant difference in dose given when compared to a lean control group. If the test dose is based on lean body mass, no significant difference in intestinal permeability is observed, even with large group sizes. Furthermore, we showed a dose-dependent difference in plasma FD-4 levels in lean mice. Therefore, we conclude that the dose should be based on lean body mass for the FD-4 permeability test if mice with considerable obesity differences are to be compared or to use another test with fixed doses.
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Intestinos , Obesidad , Ratones , Animales , Ratones Obesos , Obesidad/metabolismo , Permeabilidad , Ratones Endogámicos C57BLRESUMEN
N9-GP/Rebinyn®/Refixia® is an approved PEGylated (polyethylene glycol-conjugated) recombinant human factor IX intended for prophylactic and/or on-demand treatment in adults and children with haemophilia B. A juvenile neurotoxicity study was conducted in male rats to evaluate effects on neurodevelopment, sexual maturation, and fertility following repeat-dosing of N9-GP. Male rats were dosed twice weekly from Day 21 of age with N9-GP or vehicle for 10 weeks, followed by a dosing-free recovery period for 13 weeks and terminated throughout the dosing and recovery periods. Overall, dosing N9-GP to juvenile rats did not result in any functional or pathological effects, as measured by neurobehavioural/neurocognitive tests, including motor activity, sensory function, learning and memory as well as growth, sexual maturation, and fertility. This was further supported by the extensive histopathologic evaluation of brain tissue. Exposure and distribution of polyethylene glycol was investigated in plasma, choroid plexus, cerebrospinal fluid, and brain sections. PEG did not cross the blood brain barrier and PEG exposure did not result in any effects on neurodevelopment. In conclusion, dosing of N9-GP to juvenile rats did not identify any effects on growth, sexual maturation and fertility, clinical and histological pathology, or neurodevelopment related to PEG exposure and supports the prophylactic use of N9-GP in children.
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Factor IX , Hemofilia B , Adulto , Animales , Niño , Factor IX/uso terapéutico , Fertilidad , Hemofilia B/tratamiento farmacológico , Humanos , Lactante , Masculino , Polietilenglicoles/toxicidad , Ratas , Proteínas RecombinantesRESUMEN
Exocrine glands in the submucosa of the proximal duodenum secrete alkaline fluid containing mucus to protect the intestinal mucosa from acidic stomach contents. These glands, known as Brunner's glands, express high glucagon-like peptide 1 receptor (GLP-1R) levels. Previous studies have suggested that activation of the GLP-1R induces expression of barrier protective genes in Brunner's glands. Still, the lack of a viable in vitro culture of Brunner's glands has hampered additional studies of the functional consequences of GLP-1R activation. In this study, we established a procedure to isolate and culture cells derived from murine Brunner's glands. The isolated glandular cells retained functional GLP-1R expression in culture, making this in vitro system suitable for the study of GLP-1R activation. We found that cells derived from the Brunner's glands of mice pretreated with semaglutide contained significantly more mucus compared with Brunner's glands from vehicle-treated mice. Our data suggest a protective intestinal response upon semaglutide treatment, but further studies are required to leverage the full potential of cultured Brunner's gland cells.
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Glándulas Duodenales , Receptor del Péptido 1 Similar al Glucagón , Animales , Glándulas Duodenales/química , Glándulas Duodenales/metabolismo , Técnicas de Cultivo de Célula , Duodeno/metabolismo , Receptor del Péptido 1 Similar al Glucagón/análisis , Receptor del Péptido 1 Similar al Glucagón/genética , Receptor del Péptido 1 Similar al Glucagón/metabolismo , Mucosa Intestinal/metabolismo , Masculino , Ratones , MocoRESUMEN
INTRODUCTION: Current clinical guidelines for management of diabetic peripheral neuropathy (DPN) emphasize good glycemic control. However, this has limited effect on prevention of DPN in type 2 diabetic (T2D) patients. This study investigates the effect of insulin treatment on development of DPN in a rat model of T2D to assess the underlying causes leading to DPN. METHODS: Twelve-week-old male Sprague-Dawley rats were allocated to a normal chow diet or a 45% kcal high-fat diet. After eight weeks, the high-fat fed animals received a mild dose of streptozotocin to induce hyperglycemia. Four weeks after diabetes induction, the diabetic animals were allocated into three treatment groups receiving either no insulin or insulin-releasing implants in a high or low dose. During the 12-week treatment period, blood glucose and body weight were monitored weekly, whereas Hargreaves' test was performed four, eight, and 12 weeks after treatment initiation. At study termination, several blood parameters, body composition, and neuropathy endpoints were assessed. RESULTS: Insulin treatment lowered blood glucose in a dose-dependent manner. In addition, both doses of insulin lowered lipids and increased body fat percentage. High-dose insulin treatment attenuated small nerve fiber damage assessed by Hargreaves' test and intraepidermal nerve fiber density compared to untreated diabetes and low-dose insulin; however, neuropathy was not completely prevented by tight glycemic control. Linear regression analysis revealed that glycemic status, circulating lipids, and sciatic nerve sorbitol level were all negatively associated with the small nerve fiber damage observed. CONCLUSION: In summary, our data suggest that high-dose insulin treatment attenuates small nerve fiber damage. Furthermore, data also indicate that both poor glycemic control and dyslipidemia are associated with disease progression. Consequently, this rat model of T2D seems to fit well with progression of DPN in humans and could be a relevant preclinical model to use in relation to research investigating treatment opportunities for DPN.
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Diabetes Mellitus Experimental/tratamiento farmacológico , Neuropatías Diabéticas/prevención & control , Insulina/uso terapéutico , Neuropatía de Fibras Pequeñas/prevención & control , Animales , Glucemia/efectos de los fármacos , Glucemia/metabolismo , Diabetes Mellitus Experimental/complicaciones , Diabetes Mellitus Experimental/patología , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/patología , Dieta Alta en Grasa , Progresión de la Enfermedad , Humanos , Masculino , Fibras Nerviosas/efectos de los fármacos , Fibras Nerviosas/fisiología , Obesidad/complicaciones , Obesidad/tratamiento farmacológico , Obesidad/patología , Ratas , Ratas Sprague-Dawley , Nervio Ciático/efectos de los fármacos , Nervio Ciático/fisiologíaRESUMEN
Diabetic human patients have increased risk of heart failure compared to healthy subjects. The underlying mechanisms for this are not fully understood, and to help develop improved treatment strategies, well-characterized animal models are essential. To investigate cardiac dysfunction in diabetes, this study evaluated myocardial changes in 10 aging rhesus monkeys with and without diabetes. Based on evaluation of plasma glycosylated hemoglobin and glucose, 7 of 10 rhesus macaques had diabetes for a minimum of 11 months, while 3 of 10 were categorized as nondiabetic. A detailed histological examination of formalin-fixed left ventricular myocardial samples was followed by a semiquantitative evaluation of myocardial fibrosis and fat infiltration; digital quantifications of myocardial collagen, lipofuscin, and nuclear area fractions; and measurements of cardiomyocyte diameter. Histological myocardial evaluation revealed the presence of lipofuscin; large nuclei; interstitial, replacement, and vascular fibrosis; adipocyte infiltration; and vacuolar degeneration with atrophy of cardiomyocytes and fibrosis. However, there were no differences between groups for semiquantitative fat infiltration, fibrosis, cardiomyocyte size, collagen, or nuclear and lipofuscin area fraction. Lipofuscin area fraction correlated with plasma insulin, triglyceride, total cholesterol, and high-density lipoprotein cholesterol concentrations. In conclusion, myocardial pathological changes were found in left ventricular myocardium in aged rhesus macaques, independent of the stage of diabetes. The duration of diabetes might have been too short to cause differences between groups.
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Diabetes Mellitus/veterinaria , Cardiomiopatías Diabéticas/veterinaria , Fibrosis/veterinaria , Enfermedades de los Monos/patología , Animales , Diabetes Mellitus/patología , Cardiomiopatías Diabéticas/patología , Femenino , Fibrosis/patología , Ventrículos Cardíacos/patología , Hipertrofia/veterinaria , Macaca mulatta , Masculino , Miocardio/patología , Miocitos Cardíacos/patologíaRESUMEN
BACKGROUND AND AIMS: The advantage of combining molecular and morphological imaging, e.g. positron emission tomography and magnetic resonance imaging (PET/MRI), is reflected in the increased use of these modalities as surrogate end-points in clinical trials. This study aimed at evaluating plaque inflammation using 18F-fluorodeoxyglucose (18F-FDG)-PET/MRI, and gene expression in a minipig model of atherosclerosis. METHODS: Göttingen Minipigs were fed for 60 weeks with fat/fructose/cholesterol-rich diet (FFC), chow (Control) or FFC-diet changed to chow midway (diet normalization group; DNO). In all groups, 18F-FDG-PET/MRI of the abdominal aorta was assessed midway and at study-end. The aorta was analyzed using histology and gene expression. RESULTS: At study-end, FFC had significantly higher FDG-uptake compared to Control (target-to-background maximal uptake, TBRMax (95% confidence interval) CITBRMax: 0.092; 7.32) and DNO showed significantly decreased uptake compared to FFC (CITBRMax: -5.94;-0.07). No difference was observed between DNO and Control (CITBRMax: -2.71; 4.11). FFC displayed increased atherosclerosis and gene expression of inflammatory markers, including vascular cell adhesion molecule 1 (VCAM-1), cluster of differentiation 68 (CD68), matrix metalloproteinase 9 (MMP9), cathepsin K (CTSK) and secreted phosphoprotein 1 (SPP1) compared to Control and DNO (all, pâ¯<â¯0.05). FDG-uptake correlated with gene expression of inflammatory markers, including CD68, ρsâ¯=â¯0.58; MMP9, ρsâ¯=â¯0.46; SPP1, ρsâ¯=â¯0.44 and CTSK, ρsâ¯=â¯0.49; (pâ¯≤â¯0.01 for all). CONCLUSIONS: In a model of atherosclerosis, 18F-FDG-PET/MRI technology allows for detection of inflammation in atherosclerotic plaques, consistent with increased inflammatory gene expression. Our findings corroborate clinical data and are important in pre-clinical drug development targeting plaque inflammation.
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Aterosclerosis/diagnóstico por imagen , Fluorodesoxiglucosa F18 , Imagen por Resonancia Magnética , Tomografía de Emisión de Positrones , Radiofármacos , Animales , Aterosclerosis/genética , Correlación de Datos , Modelos Animales de Enfermedad , Expresión Génica , Imagen por Resonancia Magnética/métodos , Masculino , Tomografía de Emisión de Positrones/métodos , Porcinos , Porcinos EnanosRESUMEN
Oral administration of therapeutic peptides is hindered by poor absorption across the gastrointestinal barrier and extensive degradation by proteolytic enzymes. Here, we investigated the absorption of orally delivered semaglutide, a glucagon-like peptide-1 analog, coformulated with the absorption enhancer sodium N-[8-(2-hydroxybenzoyl) aminocaprylate] (SNAC) in a tablet. In contrast to intestinal absorption usually seen with small molecules, clinical and preclinical dog studies revealed that absorption of semaglutide takes place in the stomach, is confined to an area in close proximity to the tablet surface, and requires coformulation with SNAC. SNAC protects against enzymatic degradation via local buffering actions and only transiently enhances absorption. The mechanism of absorption is shown to be compound specific, transcellular, and without any evidence of effect on tight junctions. These data have implications for understanding how highly efficacious and specific therapeutic peptides could be transformed from injectable to tablet-based oral therapies.
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Receptor del Péptido 1 Similar al Glucagón/agonistas , Péptidos Similares al Glucagón/farmacología , Absorción Intestinal , Estómago/fisiología , Administración Oral , Adolescente , Adulto , Anciano , Animales , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Perros , Células Epiteliales/efectos de los fármacos , Células Epiteliales/metabolismo , Mucosa Gástrica/efectos de los fármacos , Mucosa Gástrica/ultraestructura , Péptido 1 Similar al Glucagón/análogos & derivados , Receptor del Péptido 1 Similar al Glucagón/metabolismo , Péptidos Similares al Glucagón/administración & dosificación , Péptidos Similares al Glucagón/farmacocinética , Humanos , Concentración de Iones de Hidrógeno , Masculino , Persona de Mediana Edad , Ratas , Estómago/efectos de los fármacos , Factores de Tiempo , Adulto JovenRESUMEN
Immunotherapy for type 1 diabetes (T1D) has previously focused on suppressing the autoimmune response against pancreatic beta cells to preserve endogenous insulin production and regulate glucose levels. With increased attention toward combination therapy strategies, studies indicate the multifunctional cytokine interleukin-21 (IL-21) may be a suitable target as an immuno-modulatory arm, while glucagon-like peptide-1 receptor (GLP-1R) agonists may be appropriate as a beta cell protective arm in combination therapy for T1D. We report here that treatment with anti-IL-21 monoclonal antibody delays diabetes onset in the spontaneous non-obese diabetic (NOD) and NOD.scid adoptive transfer models, while its effect in reversing recent-onset hyperglycemia is limited. However, the combination of anti-IL-21 plus the GLP-1R agonist liraglutide is effective in reversing established disease compared to either monotherapy in both the NOD and rat insulin promotor-lymphocytic choriomeningitis virus glycoprotein (RIP-LCMV-GP) models of autoimmune diabetes. Enhanced efficacy is particularly evident in severely hyperglycemic mice, with return to normoglycemia remaining stable for the majority of mice even after therapy is withdrawn. Importantly, increased beta cell proliferation does not appear to be the predominant mechanism. In conclusion, combination therapy with anti-IL-21 and liraglutide is able to consistently reverse disease in mouse models of T1D. The observed effects rival the most effective experimental disease-modifying treatments tested in preclinical studies.
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Anticuerpos Monoclonales/uso terapéutico , Diabetes Mellitus Tipo 1/terapia , Hiperglucemia/terapia , Inmunoterapia/métodos , Células Secretoras de Insulina/inmunología , Interleucinas/inmunología , Liraglutida/uso terapéutico , Animales , Diabetes Mellitus Tipo 1/inmunología , Modelos Animales de Enfermedad , Quimioterapia Combinada , Femenino , Humanos , Hiperglucemia/inmunología , Insulina/genética , Insulina/metabolismo , Ratones , Ratones Endogámicos NOD , Ratones TransgénicosRESUMEN
AIMS: Glucagon-like peptide-1 (GLP-1) is an incretin hormone which stimulates insulin release and inhibits glucagon secretion from the pancreas in a glucose-dependent manner. Incretin-based therapies, consisting of GLP-1 receptor (GLP-1R) agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors, are used for the treatment of type 2 diabetes (T2D). Immunohistochemical studies for GLP-1R expression have been hampered previously by the use of unspecific polyclonal antibodies. This study aimed to assess the expression levels of GLP-1R in a set of T2D donor samples obtained via nPOD. METHODS: This study used a new monoclonal antibody to assess GLP-1R expression in pancreatic tissue from 23 patients with T2D, including 7 with a DPP-4 inhibitor and 1 with a history of GLP-1R agonist treatment. A software-based automated image analysis algorithm was used for quantitating intensities and area fractions of GLP-1R positive compartments. RESULTS: The highest intensity GLP-1R immunostaining was seen in beta-cells in islets (average signal intensity, 76.1 [±8.1]). GLP-1R/insulin double-labelled single cells or small clusters of cells were also frequently located within or in close vicinity of ductal epithelium in all samples and with the same GLP-1R immunostaining intensity as found in beta-cells in islets. In the exocrine pancreas a large proportion of acinar cells expressed GLP-1R with a 3-fold lower intensity of immunoreactivity as compared to beta-cells (average signal intensity 25.5 [±3,3]). Our studies did not unequivocally demonstrate GLP-1R immunoreactivity on normal-appearing ductal epithelium. Pancreatic intraepithelial neoplasia (PanINs; a form of non-invasive pancreatic ductular neoplasia) was seen in most samples, and a minority of these expressed low levels of GLP-1R. CONCLUSION: These data confirm the ubiquity of early stage PanIN lesions in patients with T2D and do not support the hypothesis that incretin-based therapies are associated with progression towards the more advanced stage PanIN lesions.
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Diabetes Mellitus Tipo 2/metabolismo , Receptor del Péptido 1 Similar al Glucagón/metabolismo , Células Secretoras de Insulina/metabolismo , Páncreas/metabolismo , Adolescente , Adulto , Anciano , Anticuerpos Monoclonales , Especificidad de Anticuerpos , Biomarcadores/metabolismo , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/patología , Femenino , Glucagón/metabolismo , Receptor del Péptido 1 Similar al Glucagón/agonistas , Humanos , Hipoglucemiantes/uso terapéutico , Procesamiento de Imagen Asistido por Computador , Inmunohistoquímica , Incretinas/uso terapéutico , Insulina/metabolismo , Células Secretoras de Insulina/efectos de los fármacos , Células Secretoras de Insulina/patología , Masculino , Persona de Mediana Edad , Páncreas/efectos de los fármacos , Páncreas/patología , Bancos de Tejidos , Adulto JovenRESUMEN
The spatial distribution of a soluble insulin formulation was visualized and quantified in 3-dimensions using X-ray computed tomography. The drug distribution was visualized for ex vivo injections in pig subcutaneous tissue. Pig subcutaneous tissue has very distinct layers, which could be separated in the tomographic reconstructions and the amount of drug in each tissue class was quantified. With a scan time of about 45min per sample, and a robust segmentation it was possible to analyze differences in the spatial drug distribution between several similar injections. It was studied how the drug distribution was effected by needle length, injection speed and injected volume. For an injected volume of 0.1ml and injection depth of 8mm about 50% of the injections were partly intramuscular. Using a 5mm needle resulted in purely subcutaneous injections with minor differences in the spatial drug distribution between injections. Increasing the injected volume from 0.1ml to 1ml did not increase the intramuscular volume fraction, but gave a significantly higher volume fraction placed in the fascia separating the deep and superficial subcutaneous fat layers. Varying the injection speed from 25l/s up to 300l/s gave no changes in the drug concentration distribution. The method presented gives novel insight into subcutaneous injections of soluble insulin drugs and can be used to optimize the injection technique for subcutaneous drug administration in preclinical studies of rodents.
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Inyecciones Subcutáneas/métodos , Insulina/administración & dosificación , Tejido Subcutáneo/metabolismo , Animales , Inyecciones Subcutáneas/instrumentación , Insulina/farmacocinética , Agujas , Porcinos , Tomografía Computarizada por Rayos XRESUMEN
Glucagon-like peptide 1 (GLP-1) analogs are increasingly being used in the treatment of type 2 diabetes. It is clear that these drugs lower blood glucose through an increase in insulin secretion and a lowering of glucagon secretion; in addition, they lower body weight and systolic blood pressure and increase heart rate. Using a new monoclonal antibody for immunohistochemistry, we detected GLP-1 receptor (GLP-1R) in important target organs in humans and monkeys. In the pancreas, GLP-1R was predominantly localized in ß-cells with a markedly weaker expression in acinar cells. Pancreatic ductal epithelial cells did not express GLP-1R. In the kidney and lung, GLP-1R was exclusively expressed in smooth muscle cells in the walls of arteries and arterioles. In the heart, GLP-1R was localized in myocytes of the sinoatrial node. In the gastrointestinal tract, the highest GLP-1R expression was seen in the Brunner's gland in the duodenum, with lower level expression in parietal cells and smooth muscle cells in the muscularis externa in the stomach and in myenteric plexus neurons throughout the gut. No GLP-1R was seen in primate liver and thyroid. GLP-1R expression seen with immunohistochemistry was confirmed by functional expression using in situ ligand binding with (125)I-GLP-1. In conclusion, these results give important new insight into the molecular mode of action of GLP-1 analogs by identifying the exact cellular localization of GLP-1R.
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Anticuerpos Monoclonales/química , Insulina/metabolismo , Receptores de Glucagón/metabolismo , Animales , Presión Sanguínea , Peso Corporal , Línea Celular , Cricetinae , Duodeno/metabolismo , Exenatida , Glucagón/metabolismo , Péptido 1 Similar al Glucagón/análogos & derivados , Péptido 1 Similar al Glucagón/química , Receptor del Péptido 1 Similar al Glucagón , Haplorrinos , Frecuencia Cardíaca , Humanos , Secreción de Insulina , Ligandos , Liraglutida , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Péptidos/química , Unión Proteica , Distribución Tisular , Transfección , Ponzoñas/químicaRESUMEN
Four dogs with acute neurological signs caused by haemorrhages in the central nervous system were diagnosed with Angiostrongylus vasorum infection as the underlying aetiology. Two dogs presented with brain lesions, one dog with spinal cord lesions and one with lesions in both the brain and spinal cord. Only one dog presented with concurrent signs of classical pulmonary angiostrongylosis (respiratory distress, cough), and only two dogs displayed overt clinical signs of haemorrhages. Results of coagulation assays were inconsistent. Neurological signs reflected the site of pathology and included seizures, various cranial nerve deficits, vestibular signs, proprioceptive deficits, ataxia and paraplegia. One dog died and three were euthanised due to lack of improvement despite medical treatment. This emphasises canine angiostrongylosis as a potential cause of fatal lesions of the central nervous system and the importance of including A. vasorum as a differential diagnosis in young dogs with acute neurological signs in Denmark.
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Angiostrongylus , Helmintiasis del Sistema Nervioso Central/veterinaria , Enfermedades de los Perros/diagnóstico , Enfermedades Pulmonares Parasitarias/veterinaria , Infecciones por Strongylida/veterinaria , Animales , Encéfalo/parasitología , Encéfalo/patología , Helmintiasis del Sistema Nervioso Central/diagnóstico , Helmintiasis del Sistema Nervioso Central/tratamiento farmacológico , Helmintiasis del Sistema Nervioso Central/parasitología , Dinamarca , Diagnóstico Diferencial , Enfermedades de los Perros/tratamiento farmacológico , Enfermedades de los Perros/parasitología , Perros , Resultado Fatal , Femenino , Hemorragia/diagnóstico , Hemorragia/parasitología , Pulmón/parasitología , Pulmón/patología , Enfermedades Pulmonares Parasitarias/diagnóstico , Enfermedades Pulmonares Parasitarias/tratamiento farmacológico , Enfermedades Pulmonares Parasitarias/parasitología , Imagen por Resonancia Magnética/veterinaria , Masculino , Infecciones por Strongylida/diagnóstico , Infecciones por Strongylida/tratamiento farmacológico , Infecciones por Strongylida/parasitologíaRESUMEN
High doses of insulin and the insulin analog AspB10 have been reported to increase mammary tumor incidence in female rats likely via receptor-mediated mechanisms, possibly involving enhanced IGF-1 receptor activation. However, insulin and IGF-1 receptor functionality and intracellular signaling in the rat mammary gland in vivo is essentially unexplored. The authors investigated the effect of a single subcutaneous dose of 600 nmol/kg human insulin or IGF-1 on Akt and ERK1/2 phosphorylation in rat liver, colon, and mammary gland. Rat tissues were examined by Western blotting and immunohistochemistry by phosphorylation-specific antibodies. Insulin as well as IGF-1 caused Akt phosphorylation in mammary epithelial cells, with myoepithelial and basal epithelial cells being most sensitive. IGF-1 caused stronger Akt phosphorylation than insulin in mammary gland epithelial cells. Phosphorylation of ERK1/2 was not influenced by insulin or IGF-1. Rather, in liver and mammary gland P-ERK1/2 appeared to correlate with estrous cycling, supporting that ERK1/2 has important physiological roles in these two organs. In short, these findings supported that the rat mammary gland epithelium expresses functional insulin and IGF-1 receptors and that phosphorylation of Akt as well as ERK1/2 may be of value in understanding the effects of exogenous insulin in the rat mammary gland and colon.
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Factor I del Crecimiento Similar a la Insulina/farmacología , Insulina/farmacología , Proteína Quinasa 1 Activada por Mitógenos/genética , Proteína Quinasa 3 Activada por Mitógenos/genética , Proteínas Proto-Oncogénicas c-akt/genética , Animales , Western Blotting , Mama/citología , Mama/efectos de los fármacos , Colon/efectos de los fármacos , Células Epiteliales/efectos de los fármacos , Femenino , Humanos , Inmunohistoquímica , Hígado/efectos de los fármacos , Glándulas Mamarias Animales/efectos de los fármacos , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Fosforilación , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas , Ratas Sprague-Dawley , Receptor IGF Tipo 1/metabolismo , Transducción de Señal/efectos de los fármacosRESUMEN
BACKGROUND: Joint lesions occur widespread in the Danish sow population and they are the most frequent cause for euthanasia. Clinically, it is generally impossible to differentiate between various types of non-inflammatory joint lesions. Consequently, it is often necessary to perform a post mortem examination in order to diagnose these lesions. A study was performed in order to examine the relation of abnormal gait and posture in sows with specific joint lesions, and thereby obtaining a clinical diagnostic tool, to be used by farmers and veterinarians for the evaluation of sows with joint problems. METHODS: The gait, posture and lesions in elbow- and knee joints of 60 randomly selected sows from one herd were scored clinically and pathologically. Associations between the scorings were estimated. RESULTS: The variables 'fore- and hind legs turned out' and 'stiff in front and rear' were associated with lesions in the elbow joint, and the variables 'hind legs turned out' and 'stiff in rear' were associated with lesions in the knee joint. CONCLUSION: It was shown that specified gait and posture variables reflected certain joint lesions. However, further studies are needed to strengthen and optimize the diagnostic tool.