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Name: Doug Happ
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What is the molecular explanation for how AZT works? Is it used mainly to prevent HIV+ women from passing the virus to their fetuses?
If yes, does it act on only one side of the placenta?

AZT is a nucleoside analog - that is, it resembles the nucleotides that a are the building blocks of DNA. When AZT gets used to build DNA, it prevents any more from being made - that is, it blocks further extension of the growing DNA chain.
AZT is used to treat HIV infections in many situations, not solely to prevent transmission from mother to fetus. AZT is used in HIV infection because the HIV virus encodes its own DNA-making enzyme (i.e, DNA polymerase) which its particularly sensitive to AZT. The side-effects of AZT arise because the DNA polymerases in our own cells are also somewhat sensitive to the drug 0- and so some of our own cells get hurt by the drug. More questions? write me directly.

Steve J Triezenberg

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