Glycogen-rich and glycogen-depleted astrocytes in the oedematous human cerebral cortex associated with brain trauma, tumours and congenital malformations: an electron microscopy study.
OBJECTIVE
The anaerobic mobilization of astrocyte glycogen in anoxic-ischemic regions of the oedematous human cerebral cortex is analysed.


METHODS
Seventeen cortical biopsies of patients with brain trauma, brain tumours and congenital malformations were examined by conventional transmission electron microscopy.


RESULTS
Glycogen-rich and glycogen-depleted, clear or dense astrocytes cell bodies were observed in anoxic ischaemic regions of different brain cortical areas in perineuronal, neuropilar and perivascular localization. Glycogen-rich astrocytes showed clear or moderately dense cytoplasm and accumulation of both beta-type or monogranular glycogen granules and alpha-type or multigranular glycogen particles. Focal regions of translucent cytoplasm were observed in areas of glycogen degradation. Glycogen-depleted astrocytes exhibited a clear cytoplasm and scarce amount or absence of beta-type glycogen granules. Coexisting glycogen-rich and glycogen-depleted neuropilar astrocytic processes were observed in the vicinity of degenerated myelinated axons and degenerated axodendritic contacts. Glycogen-rich and glycogen-depleted perivascular astrocytic processes were also found surrounding injured and collapsed cerebral capillaries.


CONCLUSIONS
The findings suggest astrocytic glycogen mobilization during anoxic and ischaemic conditions, revealing the important contribution of astrocytes on neuronal survival under conditions of energy substrate limitations.
Castejon
Orlando J
OJ
Instituto de Investigaciones Biológicas, Facultad de Medicina, Universidad del Zulia, Maracaibo, Venezuela. ocastejo@cantv.net
Diaz
Melecio
M
Castejon
Haydee V
HV
Castellano
Alan
A
D000293:Adolescent; D000328:Adult; D001253:Astrocytes / Q000378:metabolism* / Q000648:ultrastructure*; D001706:Biopsy; D001921:Brain / Q000002:abnormalities* / Q000473:pathology; D001929:Brain Edema / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D001930:Brain Injuries / Q000150:complications*; D001932:Brain Neoplasms / Q000150:complications*; D002540:Cerebral Cortex / Q000378:metabolism*; D002648:Child; D005260:Female; D006003:Glycogen / Q000172:deficiency / Q000378:metabolism*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged
D006003:Glycogen