They are toxic if massive doses are ingested ( acute oral toxicity of 2 g per kg of body weight of pure putrescine in rats, a larger dose for cadaverine ); there are no effects at all for a tenth of that dose.
32.
There's no such thing as distinctly " human " cadaverine, so how is the dog able to distinguish a place where a human body lay from a place where there was a dead rat, even after the passage of months or years?
33.
In addition, Trp ( 43 ), Tyr ( 57 ), Tyr ( 107 ), Tyr ( 366 ), and Tyr ( 368 ) of CadB are involved preferentially in cadaverine uptake at neutral pH, while only Tyr ( 90 ) of PotE is involved preferentially in putrescine uptake.
34.
Of cadaverine in particular, I have read that it is nearly impossible to clean up every trace of it from something that has had contact with it, and that it is naturally present in semen and urine ( in small quantities, but sufficient to contribute to the way they smell * to humans * ).
