Glucose 1 Flashcards
What is the sole source of energy for the brain?
Glucose
What is the range of a normal blood glucose?
70 - 120 mg/dl
What are the 3 sources of glucose?
- Gluconeogenesis
- Glycogenolysis
- Intestinal absorption
Describe intestinal absorption of glucose…
- Carbohydrates are broken down to monosaccharides by duodenal brush-border enzymes
- Glucose is activity transported across the brush border by Na-dependent carrier
- Glucose enters the portal circulation
- Glucose is transported to the liver
Post-prandially, how many hours will glucose provide fuel for cellular metabolism?
4 - 8 hours
When in a fasted state, normoglycemia is maintained with what sources?
Endogenous glucose sources
What are the 2 endogenous glucose sources?
- Gluconeogenesis
2. Glycogenolysis
Gluconeogenesis is the formation of glucose from precursors: name 3.
- Amino acids
- Lactate
- Glycerol
In which 2 organs does gluconeogenesis occur?
- Liver
2. Kidney
Why is hepatic function important to maintaining normoglycemia?
- Primary site of gluconeogenesis
2. Site of glycogen storage
Insulin increases or decreases cellular uptake of glucose?
Increases
Insulin stimulates or inhibits lipolysis?
Inhibits
What is insulin’s effect on gluconeogenesis and glycogenolysis?
Inhibition
What 4 hormones are released in response to hypoglycemia?
- Glucagon
- GH
- Adrenaline
- Cortisol
What are the 4 net effects of the diabetogenic hormones?
- Promote glycogenolysis
- Promote gluconeogenesis
- Shut down insulin secretion
- Decrease peripheral glucose use
What is the endogenous source of glucagon?
Pancreatic alpha cells
What is the endogenous source of insulin?
Pancreatic beta cells
What is the effect of the diabetogenic hormones on blood glucose?
Increases BG
What are the possible causes of hypoglycemia?
- Lack of intestinal absorption
- Lack of hepatic production
- Endocrine disorder (addison’s, insulinoma)
- Increased glucose utilization (sepsis, polycythemia)
What is the first portion of the brain affected by hypoglycemia?
Cerebral cortex
What is the first ORGAN affected by hypoglycemia?
Brain
What are 2 causes for a MILD (>45 mg/dL) hypoglycemia?
- Addison’s
2. Hepatic disease
What are 3 causes for SEVERE (<40 mg/dL) hypoglycemia?
- Sepsis
- Neoplasia
- Juvenile
What is an insulinoma?
Tumor of the pancreatic beta-cells
Would you expect hypoglycemia or hyperglycemia with an insulinoma? Why?
Hypoglycemia: Insulinoma’s secrete insulin
Are most insulinomas benign or malignant?
Malignant
What finding would be diagnostic of an insulinoma?
High insulin with concurrent low blood glucose
What are the 3 general causes of hyperglycemia?
- Post-prandial
- Excess hormones that raise BG
- Deficit in hormones that decrease BG
What is the therapy for hyperglycemia?
Insulin
Therapy for hyperglycemia (insulin) is usually only indicated for what condition?
Acromegaly
What is the renal threshold for blood glucose in the dog?
180 mg/dL
What is the renal threshold for blood glucose in the cat?
280 mg/dL
What pancreatic cells produce insulin?
Beta
What pancreatic cells produce glucagon?
Alpha
What pancreatic cells produce somatostatin?
Gamma
What is the result of insulin deficiency?
Hyperglycemia
Explain how polyuria and polydipsia develop in a diabetic patient…
- Hyperglycemia
- Blood glucose levels exceed renal threshold
- Glucosuria
- Osmotic diuresis
- Polyuria
- Compensatory polydipsia
Explain how polyphagia develops in a diabetic patient…
- Insulin deficiency
- Glucose does not enter the satiety center
- Failure to inhibit feeding center
- Polyphagia
What are the 4 classical signs of diabetes mellitus?
- PU
- PD
- PP
- Weight loss
What is the most common endocrine disease in dogs and cats?
Diabetes mellitus
What would be a common signalment of a dog most likely to develop diabetes?
Female
7 - 10 years old
Samoyed, Keeshond
What would be a common signalment of a cat most likely to develop diabetes?
Neutered male
> 6 years of age
Australian, Burmese
Which type of DM is most common in dogs?
Type I
Which type of DM is most common in cats?
Type II
Which type of DM is insulin-dependent?
Type I
Which type of DM is non-insulin dependent?
Type II
Which type of DM is due to genetic predispositions?
Type I
Which type of DM is due to defective pancreatic beta cells?
Type II
How would you diagnose diabetes mellitus? Name 3 findings that would support a diagnosis.
- Resting hyperglycemia
- Glucosuria
- Clinical signs