Adipose Physiology Flashcards
what are the functions of adipose tissue
- thermal and mechanical insulation
- energy storage and release
- endocrine functions (produce hormones and cytokines)
what are the main adipose depots
regions of adipose deposition in the body:
1. subcutaneous (largest)
2. visceral
3. brown adipose tissue
visceral adipose tissue
intra-abdominal - deposited in the mesentery and omentum
venous drainage goes directly to the liver - exposes the liver to FFAs released by visceral adipose
brown adipose tissue
thermogenic fat located in specific regions; more abundant in young animals
obesity
excess adipose tissue
predisposes to insulin resistance (diabetes), other diseases, and anesthetic/surgical complications
is adipose tissue vascularized
yes - highly vascularized
what type of inflammatory cell is found in adipose
macrophages - releases proinflammatory cytokines
large vs small adipocytes
small: insulin sensitive
large: insulin resistant, secretes more leptin and MCP-1 and less adiponectin
what does MCP-1 do
attracts macrophages and contributes to adipose inflammation
insulin
increases glucose uptake (GLUT4), fatty acid uptake (LPL), and triglyceride storage by inhibiting lipolysis (HSL) and FFA release in adipose tissue
increases leptin production in adipose tissue
leptin
decreases food intake and increases energy expenditure
also regulates reproduction and immune functions
what receptor does leptin use
cytokine (JAK/STAT) receptor
adiponectin
anti-inflammatory and increases insulin sensitivity
increases fat oxidation in the liver and muscle
inflammatory cytokines
TNFa and IL-6; produced by macrophages in adipose tissue
contributes to insulin resistance
