End 8 - Diabetes Flashcards
What are the 4 functions of glucagon?
Stimulates gluconeogenesis. Causes glycogenolysis. Stimulates lipolysis. Stimulates insulin secretion.
What are the steps to make insulin from pre-proinsulin?
Pre-proinsulin is cleaved into proinsulin. Then proinsuln is cleaved into insulin and C-peptide.
What is measuring C-peptide useful for?
Differentiate b/w DM I and DM II. Differentiate causes of hypoglycemia (Low C-peptide in exogenous insulin like insulin shots or High C-peptide in high endogenous insulin like insulinoma).
What does GLUT-2 do? Where is it found?
It is an insulin-independent Glucose transporter; it does not require insulin so it can gauge closely the glucose levels in blood. It is found in the beta-cells, liver, small intestines, and renal cells.
What does GLUT-4 do? Where is it found?
It is a insulin-DEPENDENT glucose transporter. Found in adipose tissue and skeletal muscle.
What does GLUT-1 do? Where is it found?
They are insulin-INdependet glucose transporters. They are found in RBCs and brain.
Which hormone of the pancreas causes increased glycogen synthesis, Increased TG synthesis and protein synthesis?
Insulin.
What are the symptoms of Diabetes?
Hyperglycemia. Polyuria. Polydipsia. Polyphagia. Weight loss.
What emergency disease is mostly associated w/ DM I?
Diabetic Ketoacidosis (DKA).
What emergency disease is mostly associated w/ DM II?
Hyperosmolar hyperglycemic state (HHS).
What is the cause of DM I? What genes are associate w/ it?
Autoimmune destruction of beta cells by Islet cell antibody against glutamic acid decarboxylase (GAD). Association w/ HLA genes on chromosome 6 (HLA-DR3-DQ2, HLA-DR4-DQ8).
What is the cause of DM II?
Insulin resistance that evolves to inadequate insulin to beta-cell failure.
What are the two ways to diagnose Diabetes Mellitus?
Glucose-based testing: Fasting serum glucose or 2-hour glucose tolerance test. Hemoglobin A1C: much more stable.
What are the complications of Diabetes Mellitus?
Retinopathy. Nephropathy. Vascular disease. Motor neuropathy. Sensory neuropathy. Autonomic neuropathy. Foot sores.
Why can DM cause retinopathy?
The nonenzymatic glycosilation damages blood vessels, making them leaky; nonproliferative retinopathy. If it progresses it becomes proliferative retinopathy (where fragile new blood vessels form in the eye, and when they break causes hemorrhage and progress to blindness). Causes hard exudates, soft exudates (Cotton-wool spots) and macular edema.
What are the two primary mechanisms of action of damage caused by Diabetes Mellitus?
Nonenzymatic Glycosylation. Osmotic damage.
Why can DM cause nephropathy?
Nonenzymatic glycosylation of the small vessels in the kidney causes progressive proteinuria. Causes Kimmelstiel-Wilson nodules (acellular nodules in the glomerulus).
What drug can reduce the progressive proteinuria caused by DM?
ACE inhibitors.
Why does Diabetes cause osmotic damage? Which organs are affected?
Glucose is converted to Sorbitol by the enzyme Aldose reductase. Then, the Sorbitol is converted to Fructose by Sorbitol dehydrogenase. Tissues that have aldose reductase but not sorbitol dehydrogenase, end up storing a lot of Sorbitol. This sorbitol acts as an osmotic, pulling in water into the cell, causing damage. Tissues that lack sorbitol dehydrogenase are Schwann cells, Lens, Retina and Kidney.
How is hemoglobin glycosylated in diabetes mellitus to form HgbA1c?
By nonenzymatic glycosylation: too much glucose around that it just sticks to the hemoglobin.
Which type of diabetes mellitus fits the following description: Associated w/ obesity.
DM II.
Which type of diabetes mellitus fits the following description: may cause ketoacidosis.
DM I.
Which type of diabetes mellitus fits the following description: Strong genetic predisposition.
DM II.
Which type of diabetes mellitus fits the following description: associated w/ HLA DR3 and DR4.
DM I.
In which tissue will you find GLUT-2 receptors?
Beta-cells of pancreas. Small intestine. Liver. Kidney.
Which tissues depend on insulin for glucose uptake?
Adipose tissue. Skeletal muscle.
What is the enzyme that converts glucose to sorbitol?
Aldose reductase.
Which tissues lack sorbitol dehydrogenase, the enzyme that converts sorbitol to fructose?
Schwann cells. Lens and retina of the eye. Kidneys.
