Activity of S-adenosylmethionine decarboxylase, a key regulatory enzyme in polyamine biosynthesis, is increased in epileptogenic human cortex.
OBJECTIVE
We measured the activity of S-adenosylmethionine decarboxylase, a key regulatory enzyme of polyamine biosynthesis, in the temporal cortex of patients with epilepsy.


METHODS
Cortical surgical specimens were obtained following anterior temporal lobe resection for intractable epilepsy. Enzyme activity was compared in nonepileptogenic (n = 16) and epileptogenic (spontaneously discharging; n = 19) regions.


RESULTS
Mean enzyme activity was increased by 44% in samples from epileptogenic cortex compared with samples from nonepileptic regions. The S-adenosylmethionine decarboxylase activity in regions of focal epileptogenic discharges was also increased in five patients compared with paired samples from the nonepileptogenic portion of the same gyrus (+55%).


CONCLUSIONS
Elevated activity of S-adenosylmethionine decarboxylase in regions of active epileptogenic cortical discharges suggests that a disturbance of the polyamine system may be involved in the maintenance of hypersynchronous discharges, perhaps through a modulatory action at the excitatory N-methyl-D-aspartate-preferring glutamate receptor.
Morrison
L D
LD
Human Neurochemical Pathology Laboratory, Clarke Institute of Psychiatry, Toronto, Ontario.
Sherwin
A L
AL
Carmant
L
L
Kish
S J
SJ
D012437:Adenosylmethionine Decarboxylase / Q000096:biosynthesis*; D000293:Adolescent; D000328:Adult; D002540:Cerebral Cortex / Q000201:enzymology*; D004827:Epilepsy / Q000201:enzymology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011073:Polyamines / Q000378:metabolism*
D011073:Polyamines; D012437:Adenosylmethionine Decarboxylase