Focal ischemia in the cerebral cortex has an effect on the neurohypophysis. II. Angiogenesis in the neurohypophysis is a consequence of the focal ischemia in the cerebral cortex.
OBJECTIVE
Focal ischemia in the cerebral cortex has an effect on neurohypophysis. The morphological changes of microvessels of neurohypophysis were evaluated in a model of the cerebral infarction initiated by a photochemical reaction in the cerebral cortex. After photochemically induced platelet aggregation, we observed the morphological features of angiogenesis.


METHODS
The model of photochemically-induced cerebral ischemia was used. Seven days after intravenous injection of rose bengal and irradiation from a halogen lamp source through an intact cranium, the sampled material from neurohypophysis is processed for transmission electron microscopy using standard procedures.


RESULTS
We observed morphological features of the new vessel formation: the alterations in the endothelium and extracellular matrix during separation of the endothelial cell from each other in a "mother" vessel, the migration of the endothelial cells in the extracellular matrix, the communication of the lumen of the new and the "mother" vessels.


CONCLUSIONS
We observed development of the angiogenic phenotype in the neurohypophysis after focal ischemia in the cerebral cortex. The endothelium, basement membrane and extracellular matrix undergo morphological alterations which lead to new blood vessel formation.
Frontczak-Baniewicz
M
M
Laboratory of the Cell Ultrastructure, Medical Research Centre Polish Academy of Sciences, Pawinskiego St. 5, 02-106 Warsaw, Poland. gosia@cmdik.pan.pl
Gajkowska
B
B
D000818:Animals; D002545:Brain Ischemia / Q000139:chemically induced / Q000503:physiopathology*; D002196:Capillaries / Q000648:ultrastructure; D002450:Cell Communication; D002465:Cell Movement; D002540:Cerebral Cortex / Q000098:blood supply*; D004730:Endothelium, Vascular / Q000648:ultrastructure; D005109:Extracellular Matrix / Q000648:ultrastructure; D007365:Intercellular Junctions / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D018919:Neovascularization, Physiologic; D010777:Photochemistry; D010904:Pituitary Gland, Posterior / Q000098:blood supply*; D051381:Rats; D017208:Rats, Wistar; D012395:Rose Bengal
D012395:Rose Bengal