Insulin homeostasis: - Under fasting conditions, insulin is released in a ❌ manner every ❌ mins. - In response to increased glucose: Phase 1: insulin release within ❌, peak at ❌ mins Phase 2: more ❌ release with a ❌ peak
Choose the incorrect statement about insulin.
Insulin acts on a plasma membrane receptor which activates a cascade of signalling events.
Insulin has anabolic effects resulting in uptake, use, and storage of glucose, lipids, and amino acids.
Insulin inhbits glycogenesis, lipogenesis, and protein synthesis.
Insulin controls gene transcription and mRNA translation.
Which of these is not a diabetic medication used in NZ?
Exogenous insulin
Sulphonyureas
DPP-4 inhibitors
Alpha glucosidase inhibitors
Biguanides
1,4-DDPs
Thiazolidinediones
Sulphonylureas stimulate insulin release by binding to a specific site on the beta islet cell's ❌ complex (SUR) and ❌ its activity. Inhibition causes cell membrane ❌ and insulin ❌. Their effect declines over ❌ because of down-regulation of cell surface ❌ and progression of beta islet cell failure. Side effects are hypoglycaemia and initial ❌ gain, less-common side effects include nausea, vomiting, cholestatic jaundice, and agranulocytosis.
DPP-4 is dipeptidyl peptidase 4, a serine protease that is widely distributed throughout the body. It ❌ GLP-1. Inhibiting ❌ cause increase in plasma ❌, resulting in higher insulin secretion.
Alpha glucosidase inhibitors reduce the intestinal ❌ of starch, dextrin, and disaccharides by inhibiting the action of ❌ in the intestinal brush border. They are taken ❌ each meal and not absorbed. They are often used in ❌ with other meds. Side effects are malabsorption, flatulence, diarrhoea, and abdominal bloating.
Biguanides include metformin. Metformin reduces ❌ glucose production by ❌ gluconeogenesis. It activates ❌ (AMPK), leading to stimulation of: - hepatic ❌ oxidation - ❌ uptake - non-oxidative glucose ❌ - ❌ of lipogenesis and gluconeogenesis. Side effects are GI: nausea, indigestion, abdominal cramps, bloating, diarrhoea.
Thiazolidinediones are PPAR-gamma inhibitors that cause insulin sensitisation. The PPARγ receptor is a ❌ involved in the regulation of genes related to ❌. PPARγ receptors are expressed primarily in adipose tissue. They promote uptake of circulating fatty acids into ❌ cells, and glucose uptake into ❌ tissue. They ❌ insulin resistance. Side effects are weight ❌ and oedema.
SGLT2 is a Na+-glucose cotransporter located in the proximal portion of the ❌ tubule. It reabsorbs ❌. SGLT2 inhibitors ❌ glucose transport thus ❌ blood glucose. Side effects: - A 1%-2% increase in lower ❌ infections. - A 3%-5% increase in ❌ mycotic infections. - Mild ❌, which can lead to hypotension. - Effectiveness decreases by 40%–80% in kidney disease (GFR 60–30 mL/min).
