Endocrine Pancreas Flashcards
What are the tissues that require insulin for effective uptake of glucose?
adipose tissue
resting sk. muscles
liver because of glucokinase sitmulation
What are tissues by which glucose uptake is not affected by insulin?
nervous tissue
kidney tubules
intestinal mucosa
RBC
B-cells of pancreas
Besides insulin, what are other hormones that are considered to be anabolic?
thyroid hormone
GH/IGF1
sex steroids (androgens)
Which enzymes found in the muscles and liver are increased with insulin increases?
activity of those enzymes that promote glycogen synthesis (glucokinase and glycogen synthetase) are increased
(glucokinase not found in muscle)
What enzymes found in the liver and muscle are decreased with increased insulin levels?
activity of enzymes that break down glycogen
(phosphorylase and glucose-6-phosphatase)
glucokinase and G-6-phosphatase are expressed by liver but not by muscle
What is function of LPL?
lipoprotein lipase is located on the endothelium of capillaries and catalyzes the release of FFAs from TGs
What are insulins effects on K+?
insulin increases activity of Na/K ATPase in most body tissues
Be able to draw out a diagram on effects on increased insulin levels on the adipose cell.
What second messenger does glucagon stimulate?
cAMP leading to an increase in protein kinase A
What is the primary target tissue for glucagon?
liver
Entrance of glucose into the B cells of the pancreas closes what channels?
ATP sensitive K+ channels
What are some actions of glucagon on the liver?
- increases liver glycogenolysis
- increases liver gluconeogenesis
- increases liver ketogenesis and decreases lipogenesis
- increases ureagenesis
- increases insulin secretion
- increases lipolysis in the liver
What are some major stimuli that promote glucagon secretion?
hypoglycemia
amino acids arginine
What is the meaning of metabolic syndrome (syndrome X)
a group of derangements that includes atherogenic dyslipidemia (low HDL) and high triglycerides, elvated blood glucose, HTN, central obesity, prothrombotic state, and a proinflammatory state
clustering of all these risk factors increases probability of developing cardiovascular disease
How does having Type 1 diabetes affect the concentration of K+?
hydrogen ions move intracellulary to be buffered, and potassium ions leave the cell, reducing intracellular concnetration
There is lack of normal insulin effect of pumping potassium ions into cells
consequently, hyperkalemia is typical, but plasma K+ may be normal or low because of renal loss
