| Ever wonder why asian people always turn red after one beer, one shot, or however small the amount of alcohol?
There is a degree of flushing, from light pink, to bright red. Biologically, the
reaction has been found to be caused by a mutation in the structural
gene for the mitochondrial aldehyde dehydrogenase. Approximately 500 female Asians have a deficiency in low Km aldehyde
dehydrogenase (ALDH2), which is the result of inheritance of a mutant
ALDH2*2 allele. The mutation has the effect of both
reducing enzyme activity and increasing the turnover of this activity.
ALDH2, located mainly in mitochondria, is
responsible for the oxidation of most of the acetaldehyde generated in
alcohol metabolism. Acetaldehyde normally is
removed by ALDH, but a deficiency of the mitochondrial form means prevalence of the cystolic version. Cystolic ALDH2 has a high Km, which causes a lower affinity for acetaldehyde. This leads to
slower conversion of acetaldehyde to acetate, giving a steady-state
level of acetaldehyde. Acetaldehyde therefore accumulates in the
blood of individuals deficient in ALDH2 activity, even after small
doses of alcohol. The build up of acetaldehyde results in vasodilation, causing facial flushing.
So when you go to a party or whatever and you turn red, your aldehyde dehydrogenase is not as effecient as... mine 
|
| |
