Differential glial and vascular expression of endothelins and their receptors in rat brain after neurotrauma.
We characterized the time-course, intensity of expression and cellular origin of components of the endothelin (ET) system in the rat brain after a standardized neurotrauma (cryogenic lesion of the parietal cortex). ET mRNAs were expressed at sham level after neurotrauma, whereas immunoreactivity for ET-1 was enhanced in glia and endothelium of the lesioned hemisphere and both hippocampi. The number of ET-3 positive mononuclear cells in the lesion perimeter increased starting at 24h after injury. At 48h after neurotrauma, ET-receptor immunoreactivity was increased in astrocytes. In basilar artery endothelium, ETB-immunoreactivity was reduced at 48h to 72h recovering at 7 days whereas ETA-receptor and ET-peptide immunoreactivities were not altered. In summary, neurotrauma leads to a multicellular stimulation of endothelins in the brain along with a delayed selective loss of vascular ETB-receptors. These changes seem to be posttranscriptional and cell type specific. They favor vasoconstriction increasing the risk of late vasospasm and ischemia.
Sirén
A L
AL
Department of Psychiatry, Georg-August University, and Max-Planck-Institute for Experimental Medicine, Goettingen, Germany. Siren@em.mpg.de
Knerlich
F
F
Schilling
L
L
Kamrowski-Kruck
H
H
Hahn
A
A
Ehrenreich
H
H
D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000378:metabolism*; D001930:Brain Injuries / Q000378:metabolism*; D017931:DNA Primers; D019332:Endothelin-1 / Q000235:genetics / Q000378:metabolism*; D007150:Immunohistochemistry; D008297:Male; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D017466:Receptors, Endothelin / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D017931:DNA Primers; D019332:Endothelin-1; D012333:RNA, Messenger; D017466:Receptors, Endothelin