Obesity 1 Flashcards
How do you calculate BMI?
Kg/m2
Why is waist circumference/waist-to-hip ratio/waist-to-hight ratio measured?
used to assess regional differences in body fat deposition
Most commonly used measures of regional adiposity
What is leptin and where is it secreted from?
Signal that monitors fat stores
Adipocytes synthesize and release it into the blood
What effect does leptin have on the brain?
Leptin receptors in brain—leptin effector system in hypothalamic center–influence energy intake and energy expenditure
The wild-type ob gene encodes for what and what occurs in the ob/ob mouse?
encodes for leptin
ob/ob mouse doesnt produce leptin and acts as if its starving–increasing weight and body fat
The wild-rye db gene encodes for what and what occurs in db/db mouse?
The leptin receptor
db/db mice don’t produce leptin receptors
What does the injection of leptin into the ob/ob mouse do? db/db mouse?
Decreased feeding/increased energy expenditure/decreased body weight—-by reducing the production of orexigenic effectors by the AgRP neurons in the hypothalamus and increasing the production of anorexigenic effecters by the POMC neurons
Doesn’t do this in the db/db mouse
What do orexigenic effectors do?
promote food intake but lessen energy expenditure
What do anorexigenic effectors do?
lessen food intake but promote energy expenditure
What is leptin resistance?
Obesity with increased levels of leptin leads to leptin resistance–thats why leptin doesn’t work for obesity drug
What are white fat cells for?
Fat storage and body insulation
What are brown fat cells for?
heat production–uncoupling protein UCP1 and high mito levels
What are Beige fat cells?
white adipose that has been partially converted to brown adipose—increasing # of mito and levels of UCP1
What does the uncoupling protein UCP1 do?
promotes re-entry of protons into mitochondrial matrix (without being couple with ATP synthesis)–generating heat—adaptive thermogenesis
