Biochemical evidence of crossed cerebellar diaschisis in terms of nitric oxide indicators and lipid peroxidation products in rats during focal cerebral ischemia.
OBJECTIVE
Cerebral hypoperfusion in the contralateral cerebellar hemisphere after stroke is interpreted as a functional and metabolic depression, possibly caused by a loss of excitatory afferent inputs on the corticopontocerebellar pathway terminating in the cerebellar gray matter. This phenomenon is defined as crossed cerebellar diaschisis and can be diagnosed clinically by positron emission tomography, single-photon emission computed tomography, brain magnetic resonance imaging and electroencephalography in terms of regional cerebral blood flow or metabolic rate of oxygen measurements.


METHODS
In the present study, nitric oxide indicators (nitrite and cyclic guanosine monophosphate) and lipid peroxidation products (malondialdehyde and conjugated dienes) were measured in rat cerebral cortices and cerebella after permanent right middle cerebral artery occlusion in order to assess the crossed cerebellar diaschisis.


RESULTS
Nitrite values in ipsilateral cortex were significantly higher than those in contralateral cortex at 10 (P < 0.001) and 60 (P < 0.05) min of ischemia but no significant changes were observed in both cerebellum compared to the 0 min values. In both cerebral cortex and cerebellum cGMP levels at 10 and 60 min were significantly increased (P < 0.001). This increase was marked in ipsilateral cortex and contralateral cerebellum when compared with opposite cortex and cerebellum (P < 0.001). MDA values in ipsilateral cortex were significantly higher than those in contralateral cortex at 60 min of ischemia (P < 0.05). Contralateral cerebellar MDA values were found significantly higher than those in ipsilateral cerebellum at 0 (P<0.001) and 60 (P < 0.05) min of ischemia. In ipsilateral cortex, conjugated diene values at 0, 10, 60 min of ischemia were higher than those in contralateral cortex. On the other hand 0, 10, 60 min conjugated diene levels in contralateral cerebellum were significantly higher than those in ipsilateral cerebellum (P < 0.001).


CONCLUSIONS
These findings support the interruption of the corticopontocerebellar tract as the mechanism of the crossed cerebellar diaschisis.
Serteser
M
M
Afyon Kocatepe University, School of Medicine, Department of Biochemistry, Turkey. serteser@aku.edu.tr
Ozben
T
T
Gümüşlü
S
S
Balkan
S
S
Balkan
E
E
D000344:Afferent Pathways / Q000473:pathology / Q000503:physiopathology; D000818:Animals; D002531:Cerebellum / Q000473:pathology / Q000503:physiopathology*; D002540:Cerebral Cortex / Q000473:pathology / Q000503:physiopathology*; D006152:Cyclic GMP / Q000378:metabolism; D004292:Dominance, Cerebral / Q000502:physiology*; D020244:Infarction, Middle Cerebral Artery / Q000473:pathology / Q000503:physiopathology*; D015227:Lipid Peroxidation / Q000502:physiology*; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D009573:Nitrites / Q000378:metabolism; D011149:Pons / Q000473:pathology / Q000503:physiopathology*; D051381:Rats
D009573:Nitrites; D009569:Nitric Oxide; D008315:Malondialdehyde; D006152:Cyclic GMP