Pharmacology & testing of disorders of glucose metabolism Flashcards
What is type 1 diabetes, in which species is it most common?
Inadequate insulin secretion
More common in dogs
What is type 2 diabetes, in which species is it most common?
Due to abnormal target cell responsiveness
More common in cats
Which cells control insulin secretion?
Beta cells in the pancreas
What 3 effects does increased secretion of insulin have?
- Inhibits enzymes in catabolic processes
- Stimulates enzymes in anabolism
- Increases cellular uptake of glucose and amino acids
Following the 3 major effects of an increase in insulin, what do all of these then do?
- Increase stores of glycogen, lipids and protein
- Decreases the plasma glucose concentration
What are the clinical signs of diabetes?
- Hyperglycaemia
- Weight loss (decreased protein synthesis)
- Polydipsia (thirst)
- Polyuria (excessive urine production)
- Ketoacidosis (increased ketone bodies in blood)
How do polyuria and polydipsia develop through diabetes?
- Ability of the kidneys to reabsorb filtered glucose ifs exceeded
- Glucose in urine = osmotic diuresis
- Increase in volume of urine output
- ECV decreases and plasma osmolarity increases
- Thirst centre in hypothalamus is stimulated
Where are fatty acids broken down, and by which process?
In the liver by beta-oxidation
How do excess ketone bodies form in the blood during diabetes?
- Adipose tissue in fasted state breaks down fat stores.
- Not all acetyl coA (a product of the breakdown) can enter the citric acid cycle
- Excess of this forms ketone bodies such as acetone and beta hydroxybutyrate
What CNS damage can occur due to diabetes, and how?
Level of glucose in CSF in directly proportional to blood sugar
So an excess in glucose increases the osmolarity of the CSF and draws water out of the neurons causing intracellular dehydration and cell damage
How can we test for diabetes?
- Hyperglycaemia
- Glycosuria
- Fructosamine
- Hyperlipidaemia
What is used as a treatment for diabetes?
Insulin replacement/insulin receptor agonists
- peptide that is broken down in the GI tract
- given via injection
- activated the same response as endogenous insulin
What are the 2 adverse effects of endogenous insulin?
- Hypoglycaemia
- Insulin resistance
How would you treat hyperinsulinism (overdose)?
Feed and give IV glucose
If still not responding, give glucagon
Give 3 antidiabetic agents other than insulin
- Sulphonureas
- Glipizide
- Diet
