Brain S-adenosylmethionine decarboxylase activity is increased in Alzheimer's disease.
We measured the activity of S-adenosylmethionine decarboxylase (SAMDC), a key regulatory enzyme of polyamine biosynthesis, in autopsied brain from 13 patients with Alzheimer's Disease (AD). As compared with the controls, mean enzyme activity was increased by 37-96% in all seven examined brain regions with statistically significant increases in temporal cortex (+96%), frontal cortex (+69%) and hippocampus (+90%). The elevated SAMDC may have occurred as part of a generalized polyamine response to brain injury, which has been previously described in experimental animal conditions. Above-normal SAMDC activity implies increased levels/metabolism of spermidine and spermine, two polyamines which are involved in neuronal regeneration, growth factor production, and activation of excitatory N-methyl-D-aspartate preferring glutamate receptors. Our data suggest the involvement of the polyamine system in the brain reparative and/or pathogenetic mechanisms of AD.
Morrison
L D
LD
Human Neurochemical Pathology Laboratory, Clarke Institute Of Psychiatry, Toronto, Ont., Canada.
Bergeron
C
C
Kish
S J
SJ
D012437:Adenosylmethionine Decarboxylase / Q000378:metabolism*; D000368:Aged; D000544:Alzheimer Disease / Q000201:enzymology*; D015317:Biogenic Polyamines / Q000096:biosynthesis; D001921:Brain / Q000201:enzymology*; D001923:Brain Chemistry / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male
D015317:Biogenic Polyamines; D012437:Adenosylmethionine Decarboxylase