2. Possess multiple amino groups
Putrescine, spermine & spermidine are
biologically imp
Spermine & spermidine were detected in human
semen (sperm) hence the name
3. Precursors: Ornithine & SAM ( only the four
carbon moiety but not CH3)
Ornithine decarboxylase splits off CO2 and
produce Putrescine
Ornithine decarboxylase has the shortest half
life ( 10 min) among the mammalian enzymes
It regulates polyamine synthesis
Activators: corticosteroids, testosterone, GH
4. Polyamine oxidase of liver peroxisomes oxidizes
spermine to spermidine and then to putrescine
Spemidine and putrescine are excreted in urine in
a conjugated form, as acetylated derivatives
Some amount of putrescine is also oxidized to NH3
and CO2
5. Basic in nature
Possess multiple positive charges
Hence they are readily associated
with nucleic acids
Synthesis of DNA & RNA and
proteins
6. Essential for cell growth & proliferation
Some enzymes are inhibited by
polyamines ( protein kinase)
Stabilization of membrane structure (cell
and cellular organelles)
7. The excretion of Polyamines is found to be
elevated in almost all types of cancers
Eg: leukemias; carcinoma of lungs, bladder,
kidney
Diagnostically putrescine is an ideal marker for
cell proliferation
Spermidine is suitable for the assessment of cell
destruction
