Biosynthesis of some urinary trace amines in the rat and the human.
The biosynthesis and urinary excretion of the trace amines PE, mTA, pTA and TRYP have been investigated after systemic injection in the rat and ingestion in the human. In the rat the likely precursors phe, tyr, DOPA and PE, radioactively labelled, were injected in tracer and supplemented doses. pTA was shown to be formed from PE and ptyr and in tiny amounts from phe and DOPA. mTA was formed from PE, phe and DOPA. PE was found after phe and PE injections. In the human, after ingestion of the deuterated precursors phe, ptyr, PE and try, only deuterated PE and mTA were located after phe, deuterated pTA after ptyr, deuterated PE after PE and deuterated TRYP after try. These results suggest that in the periphery pTA may be formed by p-hydroxylation of PE as well as by decarboxylation of ptyr while PE and TRYP are formed by decarboxylation of their parent amino acids phe and try respectively. PE is also a possible source of mTA but in this case hydroxylation and decarboxylation of phe and dehydroxylation and decarboxylation (or vice versa) of DOPA are also important.
D000588:Amines / Q000096:biosynthesis*; D000818:Animals; D001596:Benzylamines / Q000096:biosynthesis*; D003903:Deuterium; D006801:Humans; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D014363:Tryptamines / Q000096:biosynthesis*; D014439:Tyramine / Q000096:biosynthesis*
D000588:Amines; D001596:Benzylamines; D014363:Tryptamines; D003903:Deuterium; C028169:3-tyramine; D014439:Tyramine