bio aging final exam Ch 7.txt

  1. Calorie restriction studies
    • McCay et al: rats increased MEAN and MAXIMUM lifespans
    • Weindruch: tested chordates and invertebrates showing rate of aging lower vs controls
  2. calorie restriction effects
    • 1 tissue integrity PRESERVED
    • 2 tumor incidence and severity DELAYED
    • 3 carcinogen toxicity REDUCED
    • 4 Immuno aging DELAYED
    • 5 Age at REPRODUCTIVE maturity DELAYED
    • 6 learning ability impairment and loss of proteins in lense of eye DELAYED
    • 7 Age at onset of reproductive decline DELAYED
  3. Physiological response to calorie restriction
    • body fat DECLINES
    • switching from ad libitum to calorie restricted can increase lifespan significantly even midlife
    • calorie restricted to ad libitum early in life shows worse effects than late life
  4. 3 hypotheses to explain calorie restriction on lifespan
    • 1. developmental: McCay suggested calorie restriction increases lifespan by DELAYING SEXUAL MATURITY
    • 2. fat content: inicreased BODY FAT decreases life expectancy
    • 3. metabolic rate: calorie restriction DECREASES metabolism
    • 4. also proposal that calorie restriction increases lifespan by decreasing both FREE RADICAL production and COLLAGEN glycation (Kristal & Yu)
  5. disposable soma and calorie restriction
    • r-selected (prodigal): when resources abundant, animals lead to ad libitum feeding to go for MAX reproductive effort
    • k-selected (prudent): when resources scarce, animals cal restricted and maximize survival @ cost of reprod.
  6. toxicity
    • related to calorie restriction
    • so...started using cal restricted as controls
    • found that control mice sacrificed longevity for increase in reproductivity
  7. metabolic rate with aging
    • Richard Cutler: showed correlation to support
    • Raymond Pearl: rate of living theory, supported by...
    • 1. Homeotherms (warm blooded): environmental manipulations can cause INCREASE in metabolic rate and SHORTENED lifespan in rats in fridge.
    • 2. hibernating animals show increased lifespan when allowed to hibernate
    • 3. Poikilotherms (cold blooded): allow body to equilibrate to outside temp, so in Dros. and fish when cold temperatures had longer lifespan vs warmer temp.
  8. Steven Austad with metabolism
    • said body size is correlated to metabolic rate and longevitiy.
    • With cal. restriction, brain to body weight ratio is gonna be higher
  9. melatonin and aging
    • melatonin secretion by pineal gland associated with DEEP sleep
    • when lack of sleep, may lack melatonin
    • hibernating animals may increase longevity vs non-hibernators b/c of high melatnonin secretion
  10. Roger McCarter with exercise and cal restriction
    • exercise in housefly: caused DECREASE in lifespan
    • Exercise in homeotherms: INCREASE in MEAN lifespan, NOT in maximum lifespan (may be thru collagen glycation, NOT free radical quenching)
  11. gene therapies
    • Orr & Sohal with gene therapy: Increasing superoxide dismutase and catalase gene copy numbers can INCREASE lifespan
    • p53 gene into humans showed REGRESSION of tumor cells
    • Leptin gene (regulates body fat) may allow for longer lifespan thru cal restriction
    • dopamine receptor genes: viral delivery may help patients with Parkinson's
  12. Melatonin
    • Russel Reiter: suggested melatonin as anti-oxidant..and free radical quenching by high melatonin could be how cal. restriction increases lifespan
    • may be signal for onset of puberty: when declines during growth spurt in childhood, lowers INHIBITION of GnRH, FSH and LH
  13. pituitary gland
    hypothysectomy resulted in longer lifespan (if removed prior to sex maturity)
  14. Transplantation
    • intrinsic to the TRANSPLANTED tissue: taken from young tissues into old animals
    • seen intrinsic to recipient with young ovaries to old, in which old body can't respond to increased estrogen with FSH or LH
  15. Leading causes of Death in elderly (1990 US stats)
    • Cardiovascular diseases
    • pneumoniamalignant neoplasms
    • obstructed pulmonary disease
    • diabetes
  16. Leading causes of death in adolescents and young adults (US 1990 Stats)
    • accidents
    • homocides
    • suicides
    • HIV
  17. Exercise beneficially influences for age-related parameters
    • Vital capacity
    • body mass index
    • HDL to toal cholesterol ratio
  18. Growth hormone
    • Dan Rudman showed elderly with growth hormone showed: increased bone density, skeletal mass, skin thickness, and hand grip strength
    • Systolic BP elevated thou :(
  19. DHEA
    found to increase lifespan of rodents, possibly thru calorie restriction
  20. Retin-A
    • derivative of Vitamin A
    • Shown to stimulate cell proliferation and collagen production
Card Set
bio aging final exam Ch 7.txt
bio aging final exam ch 7 calorie restriction