Hormonal Regulation of Lipid Metabolism

Hormonal Regulation of Lipid Metabolism

Insulin:

• Stimulates lipogenesis (fat synthesis) in adipose tissue
• Inhibits lipolysis (fat breakdown) in adipose tissue
• Promotes glucose uptake in adipose tissue, which is converted to glycerol for triglyceride synthesis

Glucagon:

• Inhibits lipogenesis (fat synthesis) in adipose tissue
• Stimulates lipolysis (fat breakdown) in adipose tissue
• Releases glycerol from adipose tissue, which is then used for gluconeogenesis in the liver

Thyroid Hormones:

• Stimulate lipolysis (fat breakdown) in adipose tissue
• Increase lipoprotein lipase activity, enhancing triglyceride clearance from the bloodstream

Adiponectin:

• Produced by adipose tissue
• Stimulates fatty acid oxidation in muscle and liver
• Inhibits glucose production in liver

Leptin:

• Produced by adipose tissue
• Inhibits appetite and increases energy expenditure
• Stimulates lipolysis (fat breakdown) in adipose tissue

Hormonal Regulation of Lipoprotein Metabolism

Insulin:

• Inhibits apoC-III, an inhibitor of lipoprotein lipase
• Increases lipoprotein lipase activity, enhancing triglyceride clearance from the bloodstream

Thyroid Hormones:

• Increase apoA-I, a component of HDL
• Increase LCAT activity, enhancing cholesterol esterification in HDL

Glucocorticoids:

• Stimulate VLDL production in the liver
• Inhibit lipoprotein lipase activity, reducing triglyceride clearance from the bloodstream

Hormonal Regulation of Lipid Metabolism

• Insulin stimulates lipogenesis in adipose tissue, promoting fat synthesis and inhibiting lipolysis, or fat breakdown.
• Insulin also promotes glucose uptake in adipose tissue, which is converted to glycerol for triglyceride synthesis.
• Glucagon has the opposite effect, inhibiting lipogenesis and stimulating lipolysis, releasing glycerol from adipose tissue for gluconeogenesis in the liver.
• Thyroid hormones stimulate lipolysis in adipose tissue and increase lipoprotein lipase activity, enhancing triglyceride clearance from the bloodstream.
• Adiponectin, produced by adipose tissue, stimulates fatty acid oxidation in muscle and liver, while inhibiting glucose production in the liver.
• Leptin, also produced by adipose tissue, inhibits appetite and increases energy expenditure, while stimulating lipolysis in adipose tissue.

Hormonal Regulation of Lipoprotein Metabolism

• Insulin inhibits apoC-III, an inhibitor of lipoprotein lipase, and increases lipoprotein lipase activity, enhancing triglyceride clearance from the bloodstream.
• Thyroid hormones increase apoA-I, a component of HDL, and LCAT activity, enhancing cholesterol esterification in HDL.
• Glucocorticoids stimulate VLDL production in the liver and inhibit lipoprotein lipase activity, reducing triglyceride clearance from the bloodstream.