Endocrine Flashcards
(48 cards)
How is glucose made available to the body
Glycogenolysis: Glycogen breakdown— short term 6-12 hrs
Gluconeogensis: Production of glucose— Prolonged
Where is insulin released from
Beta cells in the pancreas when glucose is high
What are the counter regulatory methods for decreased glucose
glucagon, catecholamines, cortisol and growth hormone
Where is glucagon made and how does it work
alpha cells of pancrease.
Stimulates glycogenolysis via cAMP, phosphorylation of glycogen phosphorylase
How do catecholamines increase glucose
realsed via SNS stimulation from adrenal medulla
potienated glucagon’s activity of phosphorylase
How does gluconeogesis occur
pyruvate, lacatic acid, glycerol, and amino acids to form glucose
Cortisol mobilized protien and adipocytes for ammino acids and FFA; inhibits insulin and potientiates effects of glucagon/epi on the liver
How is the brain glucose levels compared to the rest of the body
Dependent on plasma glucose (don’t make own) 30 % less in brain cells than blood.
GLUT-1 glucose transporter for the brain
Neuronal damage, decreased cerebral ATP, cellular swelling, oxidative damage
Sympathoadrenal response
What are the broad categories of hypoglycemia
Excess secretion of insulin/ insulin like factors
Decrease glucose production
Excess glucose consumption (includes drugs)
Suprious (polycythemia, leukocytosis, error-handling)
What is an insulinoma and common signs
Functional beta cell tumor
Signs are seen after meals and exercise
Middle to large breed dogs
What are indicators on blood work of insulinoma
Hypokalemia due to insulin induced shift
low fructosamine levels
>30 insulin:glucose ratio supportive (can be seen with sepsis, non pancreatic neoplasia
What is the goal of medical management in insulinoma
Give enough dextrose for insulin there but no so much to increase insulin release.
glucacorticioids, glucagon CRI (short term)
How does stress hyperglycemia occur
200-400 mg/dl
Catecholamine excess
Increase lactate is also associated with increase hepatic glucose production
How does hyperglycemia with TBI occur
associated with catecholamine response
Degree of injury with degree of increase glucose
Generally don’t need insulin
Which ketones will react with the urine dipstick
acetone and acetoacetate
Beta-hydroxybuterate will not
What are the renal thresholds for glucose in a cat and dog
Dog 180 mg/dl
Cat 300 mg/dl
What does ketones mean with Diabetes mellitus
absolute or relative insulin deficiency promoting lipolysis
How does hyperglycemic hyperosmolar syndrome occur
sustained an insult leading to a marked reduction of GFR.
Ability to excrete glucose impaired leads to abnormal retention in the blood
What are laboratory findings of hyperosmolar hyperglycemic syndrome
Glu > 600 mg/dl
Osm/Kg > 350
Does not usually have ketones
What are the two types of diabetes
Type 1- insulin deficiency dogs; immune mediated destruction
Type 2- Insulin resistance Cats
How does insulin resistance occur
Through counter regulatory hormones (cortisol, epi, GH, progesterone elevated)
Exerts negative infulence on insulin sensitivity at the level of the insulin receptor or insulin signaling cascade
What are the negative effects of hyperglycemia
Reactive oxygen species
Pro-inflammatory cytokines (TNF alpha, IL-6, IL1 beta) - insulin resitant state
impair leukocyte function
limits neovascularization and collagen synthesis
How are ketones formed
increase glucose stimulates hormone sensitive lipase and FFAs released from adipocytes
FFAs metabolized to triglycerides, CO2/H20 or ketone bodies
Counter regulatory hormones released due to stress stimulate lipolysis leads to more FFAs
What are the mechanisms for decreased potassium in DKA/HHS
Osmotic diuresis- lytes lost along to maintain electroneutrality
Insulin defiency decrease amount of K co transported into the cell
Acidemia K shifts out of the cells in exchange for H+
Hyperosmolality
Hypervolemia induced and increased aldosterone – increase renal los
Decrease GI uptake
Why does potassium decrease when insulin is given
K+ will move into cell along with glucose (cotransport)
Acidemia improves K+ will shift into cells
