Term
| Where are lipoprotein lipases and what stimulates their activity? |
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Definition
Lipoprotein lipase is specifically found in endothelial cells lining the capillaries
Insulin is known to enhance LPL synthesis in adipocytes and its placement in the capillary endothelium.
LPL has different isozymes in different tissues. The form that is in adipocytes is activated by insulin, whereas that in muscle and myocardium is not. This helps to explain why adipose cells gain fat in a well-fed state |
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Term
| What is the cause of severe ketoacidosis in type I diabetes |
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Definition
| increased levels of acetoacetate and beta-hydroxybutarate. This results from the elevated non-esterified fatty acids and accelerated fatty acid oxidation in liver |
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Term
| What is the mechanism of gestational diabetes? |
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Definition
Placental hormones cause a physiologic insulin resistance in the mother’s
body, requiring the mother to produce as much as three times more insulin than normal. When a woman’s pancreas cannot produce that much extra insulin, she develops gestational diabetes. |
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Term
| What is is a good indicator of how high a person's average blood glucose levels were over the previous several weeks |
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Definition
| concentration of glycated hemoglobin A (hemoglobin A1c) |
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Term
| How does exercise inhibit insulin release. |
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Definition
| by sympathetic neuronal activity = increased norepinephrine |
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Term
| In addition to high blood glucose, what also increases insulin release? |
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Definition
High plasma amino acids
vagus nerve and gastrointestinal hormones when food enters the stomach |
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Term
| What is a proposed mechanism of damage caused by prolonged hyperglycemia? |
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Definition
| Increased protein glycation. This reaction is not catalyzed by an enzyme so the rate is linear to glucose concentration. Increased glycation of lens proteins may contribute to diabetic cataracts. Collagen, laminin, vitronectin and other matrix proteins can become glycated and undergo changes in protein interactions etc. Glycated proteins and lipoproteins may be involved in the formation of atherosclerotic plaques. |
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