[S-adenosyl-L-methionine concentration in cerebral interstitial fluid monitored by intracerebral microdialysis].
Ketamine-anesthetized gerbils were implanted with 0.5 mm diameter microdialysis tubing through the cortex, hippocampus and thalamus with a stereotaxic instrument. The cannula was perfused with artificial cerebrospinal fluid at a flow rate of 2 microliters/min. Samples of the perfusate representing the cerebral interstitial fluid were collected and subsequently analyzed for their content of S-adenosyl-L-methionine (SAM) with high performance liquid chromatography (HPLC). In vitro tests using the dialysis cannula gave SAM recovery which varied from 3.44 +/- 0.31% (n = 3) at a perfusion flow rate of 8 microliters/min to 43.8 +/- 3.81% (n = 3) at 0.5 microliters/min (mean +/- SEM). The in vivo SAM content of the perfusate was studied and the endogenous SAM level in cerebral interstitial fluid of gerbil was 3.49 +/- 1.52 nmol per ml (n = 3). Intraperitoneal injection of SAM (250 mg/kg) produced 10-fold increases in the perfusate SAM concentration. After the experiment the brains were checked by immunopathological study using anti-albumin antibody to examine the degree of damage to the blood-brain barrier permeability. These results show that intracerebral microdialysis offers several potential advantages for studies of extracellular neurochemistry.
Shimizu
H
H
Department of Neurosurgery, Osaka University Medical School, Japan.
Morimoto
K
K
Yoshimine
T
T
Shimada
N
N
Masana
Y
Y
Hayakawa
T
T
Hashimoto
T
T
D000818:Animals; D001812:Blood-Brain Barrier; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D001923:Brain Chemistry; D002851:Chromatography, High Pressure Liquid; D003956:Dialysis / Q000379:methods; D005110:Extracellular Space / Q000378:metabolism*; D005260:Female; D005849:Gerbillinae; D007274:Injections, Intraperitoneal; D008297:Male; D010477:Perfusion; D012436:S-Adenosylmethionine / Q000008:administration & dosage / Q000032:analysis / Q000493:pharmacokinetics*; D014018:Tissue Distribution
D012436:S-Adenosylmethionine