Treating diabetes Flashcards
What is diabetes insipidus?
Deficient vasopressin secretion which regulated water retention. Or lack of response to vasopressin.
What is diabetes mellitus?
Type I is a lack of insulin-producing cells while type II is glucose-intolerance and/or insulin resistance.
What is vasopressin?
A signaling hormone released from the hypothalamus and acts on vasopressin receptors in the kidney resulting in shuffling of aquaporins.
What happens if vasopressin is not produced or vasopressin receptors are not responding?
Large amounts of dilute urine are produced.
How is vasopressin administered?
Intranasally, if given through IV can cause spasm of coronary arteries.
What is the synthetic version of vasopressin called?
Desmopressin - has a longer half-life as it is less easily recognised by peptidases in the bloodstream.
What is Type I diabetes mellitus caused by?
Autoimmune destruction of pancreatic B-cells
What is type II diabetes mellitus caused by?
Impaired secretion of insulin, can be genetic or as a result of the environment.
What is insulin?
A peptide hormone expressed only in pancreatic B-cells
Where are insulin receptors expressed?
In the liver, muscle and fat cells.
What form of insulin is injected for fast-action?
Soluble monomeric insulin
What form of insulin is injected for slow action?
Insulin precipitated with zinc.
What is metformin?
Used to treat type II diabetes, lowers the amount of circulating glucose in the blood-stream. Reduces gluconeogenesis in the liver and increases glucose uptake and utilisation by GLUT-4 translocation in the periphery (muscle and fat)
Hoe do sulphonylureas and glinides treat type II diabetes?
Work on the pancreatic B-cells in the Islets of Langerhans and inhibit the ATP-dependent K+ channels found in the plasma membrane.
How do defects in metabolism affect KATP channels?
Prevent generation of sufficient STP to close KATP channel and allow opening of Ca2+ channels allowing insulin release.
