Endocrine Pancreas

Type 1 Insulin Dependent Diabetes Mellitus

  • occurs most frequently in dogs and cats (more so dogs though)
  • beta cell destruction (autoimmune) -> little or no production and secretion of insulin -> intracellular glucose deficiency -> diabetic ketoacidosis (switch to fat metabolism)

Insulin

Short acting insulin

Intermediate acting insulin

Long acting insulin

Regular Insulin (Humulin, Novolin)

  • used in emergencies as initial insulin therapy

Lente (Caninsulin)

  • purified porcine insulin (less likely to cause immune rxn)
  • 30% amorphous (faster peak) and 70% crystalline (longer time to peak)
  • used mostly in dogs but can also be used in cats

NPH (Neutral Protamine Hagedorn; Humulin N)

  • similar performance to lente

Glargine (Lantus)

  • use largely limited to cats
  • 2 arginines added to insulin beta chain and an asparagine is replaced with a glycine in the alpha chain -> makes absorption phase longer so its longer acting

Insulin Determir (Levemir)

  • used more so in dogs
  • fatty acid is bound to lysine in beta chain; after absorption, it binds to albumin in blood and slowly dissociates from this complex = longer acting

Protamine Zinc Insulin (PZI)

  • licensed for use in cats
  • slow absorption phase and longer duration of action

Type 2 Non-Insulin Dependent Diabetes Mellitus

  • more frequent in cats
  • *reduced insulin secretion AND reduced insulin action (aka insulin resistance)
  • risk factors = genetics, inactivity, obesity, diet, steroids and progestins
  • best treatment is not insulin but the use of oral hypoglycemics and diet

Oral Hypoglycemis

Insulin Secretagogues

  • increases release of insulin by preventing potassium from leaving the cell (ATP pump stops working)
  • these meds will only work if there is some beta cells still present

Sulfonylureas

Insulin Sensitizers
(makes cells more sensitive to insulin)

Biguanides

Glipizide

  • increases release of insulin by blocking ATP-sensitive K+ channel on beta cells

Metformin

  • reduces gluconeogenesis and increases insulin utilization by peripheral target cells (muscle, fat)

Alpha-Glucosidase inhibitors

Acarbose

  • inhibits absorption of starches and sugars

SGLT2-Sodium Glucose Cotransporter inhibitors

Bexagliflozin or Velagliflozin

  • inhibit the transporters found on proximal convoluted tubules in the kidneys so that glucose cannot be reabsorbed -> facilitates the removal of glucose through urine
  • licensed for use in cats with Type 2 diabetes mellitus
  • not available in Canada yet