Like Y-DNA STRs, autosomal STRs are counts of repeated genetic code. As autosomal DNA recombines each generation, the number of markers shared with a specific ancestor is reduced by half each generation.
Heroin acts as a lipid soluble âprodrugâ within the brain, meaning that heroin itself is inactive but it is metabolized into an active form within the body. After crossing the blood-brain barrier, heroin is metabolized into morphine, which actively binds to opiate receptors in the brain producing the high.
Extensively metabolized by the liver, only 2-12% is excreted as unchanged drug, while 60-80% is excreted as morphine-3-glucuronide. The half-life of morphine is 1.7-4.5 hours. Heroin is rapidly metabolized (plasma half-life is 3 minutes), first to 6-monoacetylmorphine (6-MAM) and further to morphine. The urinary excretion profile is similar to morphine, in that 7% is excreted as unchanged morphine and 50-60% as glucuronides. Trace amounts of 6-MAM, a specific metabolite of heroin, are also excreted for approximately 6-8 hours following heroin use.