By-products of protein and amino acid metabolism
Urea80% of total (excreted nitrogen)
Guanidino compounds
Guanidine
Methylguanidine
Dimethylguanidine
Creatinine
Creatine
Guanidinosuccinic acid
Urates and hippurates
End products of nucleic acid metabolism
End products of aliphatic amine metabolism
End products of aromatic amino acid metabolism
Tryptophan
Tyrosine
Phenylalanine
Other nitrogenous substances
Polyamines
Myoinositol
Phenols
Benzoates
Indoles
Advanced glycation end products
Inhibitors of ligand-protein binding
Glucuronoconjugates and aglycones
Inhibitors of somatomedin and insulin action