Developed method showed a linear response toward Cd2+ in the concentration range of 0.25 μM to 2 μM. The limit of detection was found to be 0.1499 μM. THMPP exhibited excellent selectivity towards Cd (II) in presence of other metal ions like Hg2+, Mn2+, Mg2+, Co2+ in 1100, Zn2+, Cu2+, Ni2+ in 110 and Na+, K+ in 11 M ratio.Pancreatic beta cells have a significant remodeling capacity which plays an essential role in the maintenance of glucose homeostasis. Beta cell apoptosis, replication, size, dedifferentiation, and (neo)generation contribute to the beta cell mass regulation. However, the extent of their respective contribution varies significantly depending on the specific condition, and it is the balance among them that determines the eventual change in beta cell mass. Thus, the study of the pancreatic beta cell mass regulation requires the determination of all these factors. In this chapter, we describe the quantification of beta cell replication based on the incorporation of thymidine analogs into replicated DNA strands and on the expression of Ki67 antigen and phosphorylation of histone H3. Beta cell apoptosis is analyzed by the TUNEL technique, and beta cell mass and cross-sectional area of individual beta cells are determined by computerized image processing methods.Studies on islet of Langerhans physiology are crucial to understand the role of the endocrine pancreas in diabetes pathogenesis and the development of new therapeutic approaches. However, so far most research addressing islet of Langerhans biology relies on islets obtained via enzymatic isolation from the pancreas, which is known to cause mechanical and chemical stress, thus having a major impact on islet cell physiology. To circumvent the limitations of islet isolation, we have pioneered a platform for the study of islet physiology using the pancreas tissue slice technique. https://www.selleckchem.com/products/santacruzamate-a-cay10683.html This approach allows to explore the detailed three-dimensional morphology of intact pancreatic tissue at a cellular level and to investigate islet cell function under near-physiological conditions. The described procedure is less damaging and faster than alternative approaches and particularly advantageous for studying infiltrated and structurally damaged islets. Furthermore, pancreas tissue slices have proven valuable for acute studies of endocrine as well as exocrine cell physiology in their conserved natural environment. We here provide a detailed protocol for the preparation of mouse pancreas tissue slices, the assessment of slice viability, and the study of pancreas cell physiology by hormone secretion and immunofluorescence staining.Insulin is a hormone produced and secreted by the β-cells of the pancreatic islets of Langerhans in response to increased blood glucose levels after a meal. The hormone binds to its receptor located on the plasma membrane triggering an intracellular signaling cascade. This signaling pathway is responsible for the pleiotropic actions of insulin on different tissues, such as regulation of glucose and lipid metabolism, proliferation, and differentiation. Although considerable efforts have been made to understand the molecular mechanism linking the action of the hormone to biological processes, our knowledge is incomplete. Of note, under certain conditions, physiological circulating levels of the hormone are insufficient to properly regulate these processes, a term coined as insulin resistance. The ex vivo analysis of insulin action provides valuable information to decipher intracellular signaling events downstream of the insulin receptor under physiological and pathophysiological conditions. In this chapter, we focus on the analysis of intracellular insulin action ex vivo.Type 1 diabetes is an autoimmune disease resulting in the loss of insulin production and, consequently, hyperglycemia. The nonobese diabetic (NOD) mouse develops spontaneous diabetes with considerable similarity to the disease in humans. Immunological studies using the NOD mouse model allow for the investigation of the natural history of the disease and leukocyte and lymphocyte pathogenic and regulatory functions, as well as testing potential therapies for intervention. The analyses of the cellular events leading up to diabetes may utilize different in vitro cellular assays, immunohistochemistry, and in vivo adoptive transfer, to study mechanisms of the disease and the effects of therapeutic intervention. In this chapter, we describe some common techniques for phenotyping and mechanistic analyses of function, particularly of CD8+ T cells.Islets of Langerhans are clusters of endocrine cells embedded within the exocrine pancreas. Islets constitute only approximately 1-2% of the total pancreas mass in all species, so methods have been developed to digest the pancreas and purify islets from the surrounding acinar cells. This chapter provides detailed protocols for isolation of mouse islets and their in vitro functional characterization in terms of assessments of islet viability, hormone content and secretion, second messenger generation and β-cell proliferation.Measurement of blood glucose concentration is a common end point in studies using animal models of diabetes. Usually a blood glucose meter is used to measure non-fasted blood glucose concentrations, typically at frequencies of between 1 and 7 times per week. This process involves pricking the tip of the tail to collect a small blood sample (0.5-5 μL), which could potentially cause a stress response and affect blood glucose concentrations. Moreover, with blood glucose concentrations constantly fluctuating in response to feeding and activity, a single-point measurement can easily misrepresent the actual glycemic control of the animal. In this chapter, we discuss the use of continuous glucose monitoring in **** by radio-telemetry which allows second-by-second changes in blood glucose to be captured without restraining the mouse. Glucose excursions rather than single-point measurements may prove more useful in detecting effects of treatments, and lack of handling may avoid stress responses causing artefacts. We outline what is involved in implanting such devices into **** including some practical tips to maximize success.
Developed method showed a linear response toward Cd2+ in the concentration range of 0.25 μM to 2 μM. The limit of detection was found to be 0.1499 μM. THMPP exhibited excellent selectivity towards Cd (II) in presence of other metal ions like Hg2+, Mn2+, Mg2+, Co2+ in 1100, Zn2+, Cu2+, Ni2+ in 110 and Na+, K+ in 11 M ratio.Pancreatic beta cells have a significant remodeling capacity which plays an essential role in the maintenance of glucose homeostasis. Beta cell apoptosis, replication, size, dedifferentiation, and (neo)generation contribute to the beta cell mass regulation. However, the extent of their respective contribution varies significantly depending on the specific condition, and it is the balance among them that determines the eventual change in beta cell mass. Thus, the study of the pancreatic beta cell mass regulation requires the determination of all these factors. In this chapter, we describe the quantification of beta cell replication based on the incorporation of thymidine analogs into replicated DNA strands and on the expression of Ki67 antigen and phosphorylation of histone H3. Beta cell apoptosis is analyzed by the TUNEL technique, and beta cell mass and cross-sectional area of individual beta cells are determined by computerized image processing methods.Studies on islet of Langerhans physiology are crucial to understand the role of the endocrine pancreas in diabetes pathogenesis and the development of new therapeutic approaches. However, so far most research addressing islet of Langerhans biology relies on islets obtained via enzymatic isolation from the pancreas, which is known to cause mechanical and chemical stress, thus having a major impact on islet cell physiology. To circumvent the limitations of islet isolation, we have pioneered a platform for the study of islet physiology using the pancreas tissue slice technique. https://www.selleckchem.com/products/santacruzamate-a-cay10683.html This approach allows to explore the detailed three-dimensional morphology of intact pancreatic tissue at a cellular level and to investigate islet cell function under near-physiological conditions. The described procedure is less damaging and faster than alternative approaches and particularly advantageous for studying infiltrated and structurally damaged islets. Furthermore, pancreas tissue slices have proven valuable for acute studies of endocrine as well as exocrine cell physiology in their conserved natural environment. We here provide a detailed protocol for the preparation of mouse pancreas tissue slices, the assessment of slice viability, and the study of pancreas cell physiology by hormone secretion and immunofluorescence staining.Insulin is a hormone produced and secreted by the β-cells of the pancreatic islets of Langerhans in response to increased blood glucose levels after a meal. The hormone binds to its receptor located on the plasma membrane triggering an intracellular signaling cascade. This signaling pathway is responsible for the pleiotropic actions of insulin on different tissues, such as regulation of glucose and lipid metabolism, proliferation, and differentiation. Although considerable efforts have been made to understand the molecular mechanism linking the action of the hormone to biological processes, our knowledge is incomplete. Of note, under certain conditions, physiological circulating levels of the hormone are insufficient to properly regulate these processes, a term coined as insulin resistance. The ex vivo analysis of insulin action provides valuable information to decipher intracellular signaling events downstream of the insulin receptor under physiological and pathophysiological conditions. In this chapter, we focus on the analysis of intracellular insulin action ex vivo.Type 1 diabetes is an autoimmune disease resulting in the loss of insulin production and, consequently, hyperglycemia. The nonobese diabetic (NOD) mouse develops spontaneous diabetes with considerable similarity to the disease in humans. Immunological studies using the NOD mouse model allow for the investigation of the natural history of the disease and leukocyte and lymphocyte pathogenic and regulatory functions, as well as testing potential therapies for intervention. The analyses of the cellular events leading up to diabetes may utilize different in vitro cellular assays, immunohistochemistry, and in vivo adoptive transfer, to study mechanisms of the disease and the effects of therapeutic intervention. In this chapter, we describe some common techniques for phenotyping and mechanistic analyses of function, particularly of CD8+ T cells.Islets of Langerhans are clusters of endocrine cells embedded within the exocrine pancreas. Islets constitute only approximately 1-2% of the total pancreas mass in all species, so methods have been developed to digest the pancreas and purify islets from the surrounding acinar cells. This chapter provides detailed protocols for isolation of mouse islets and their in vitro functional characterization in terms of assessments of islet viability, hormone content and secretion, second messenger generation and β-cell proliferation.Measurement of blood glucose concentration is a common end point in studies using animal models of diabetes. Usually a blood glucose meter is used to measure non-fasted blood glucose concentrations, typically at frequencies of between 1 and 7 times per week. This process involves pricking the tip of the tail to collect a small blood sample (0.5-5 μL), which could potentially cause a stress response and affect blood glucose concentrations. Moreover, with blood glucose concentrations constantly fluctuating in response to feeding and activity, a single-point measurement can easily misrepresent the actual glycemic control of the animal. In this chapter, we discuss the use of continuous glucose monitoring in mice by radio-telemetry which allows second-by-second changes in blood glucose to be captured without restraining the mouse. Glucose excursions rather than single-point measurements may prove more useful in detecting effects of treatments, and lack of handling may avoid stress responses causing artefacts. We outline what is involved in implanting such devices into mice including some practical tips to maximize success.
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