Core mechanisms
The main organ involved with controlling glucose levels in the body is the pancreas. This organ contains specific areas known as the Islets of Langerhans which contain α cells and β cells. As this essay is focusing on the adverse effects of excess glucose in the body (hyperglycaemia) – the β cells will primary be studied as these act to lower blood glucose within the body. The cells do this by releasing a hormone known as insulin. [10]
Figure 1 – Insulin Secretion [3]
The above image shows insulin secretion stimulated by glucose. There is an uptake of glucose by the carrier protein GLUT2 when glucose levels increase in the blood [4]. GLUT 2 is found within the B-cells of the pancreas. The glucose then goes through glycolysis to become pyruvate via oxidation. Within the mitochondria of the cell, there is a pyruvate dehydrogenase complex which acts to oxidize the pyruvate [5]. This produces NADH and FADH2 which become oxidized by oxidative phosphorylation machinery leading an increase in ATP. This ATP increase goes on to inhibit an ATP sensitive potassium channel (KATP channel) [17]. This then leads to the membrane becoming depolarised which triggers an influx of Ca2+ ions. These Ca2+ ions cause the migration of a vesicle containing insulin to move to the plasma membrane which then releases …show more content…
This occurs when diabetes increases flux through accessory pathways of glucose metabolism. An example of one of these pathways is HBP (hexosamine biosynthetic pathway) – this is used to produce a sugar donor for a particular post-translational modification of proteins (β-O-linked-N-acetylglucosamine). The study found that increases in β-O-linked-N-acetylglucosamine modifications caused by high glucose was associated with ‘decreased maximal cardiomyocyte respiration, decreased mitochondrial reserve capacity and lower complex II – dependent respiration’
The main organ involved with controlling glucose levels in the body is the pancreas. This organ contains specific areas known as the Islets of Langerhans which contain α cells and β cells. As this essay is focusing on the adverse effects of excess glucose in the body (hyperglycaemia) – the β cells will primary be studied as these act to lower blood glucose within the body. The cells do this by releasing a hormone known as insulin. [10]
Figure 1 – Insulin Secretion [3]
The above image shows insulin secretion stimulated by glucose. There is an uptake of glucose by the carrier protein GLUT2 when glucose levels increase in the blood [4]. GLUT 2 is found within the B-cells of the pancreas. The glucose then goes through glycolysis to become pyruvate via oxidation. Within the mitochondria of the cell, there is a pyruvate dehydrogenase complex which acts to oxidize the pyruvate [5]. This produces NADH and FADH2 which become oxidized by oxidative phosphorylation machinery leading an increase in ATP. This ATP increase goes on to inhibit an ATP sensitive potassium channel (KATP channel) [17]. This then leads to the membrane becoming depolarised which triggers an influx of Ca2+ ions. These Ca2+ ions cause the migration of a vesicle containing insulin to move to the plasma membrane which then releases …show more content…
This occurs when diabetes increases flux through accessory pathways of glucose metabolism. An example of one of these pathways is HBP (hexosamine biosynthetic pathway) – this is used to produce a sugar donor for a particular post-translational modification of proteins (β-O-linked-N-acetylglucosamine). The study found that increases in β-O-linked-N-acetylglucosamine modifications caused by high glucose was associated with ‘decreased maximal cardiomyocyte respiration, decreased mitochondrial reserve capacity and lower complex II – dependent respiration’