Endogenous endothelin-1 initiates astrocytic growth after spinal cord injury.
We developed a rat spinal cord injury model and investigated whether endogenous endothelin (ET)-1 plays a role in astrocytic growth after injury. Immunohistochemical study showed that the number of immature astrocytes (ACs) exhibiting strong reactivity to the monoclonal antibody, RC1, markedly increased 24 h after the injury. Injection of a potent nonselective ET receptor antagonist, SB209670, into the lesion sites significantly inhibited the appearance of RC1-positive cells 24 h after the injury. In conjunction with this result, the increase in immunostaining density of 5-bromo-2'-deoxyuridine in the spinal cord 24 h after the injury was inhibited by the injection of SB209670. The tissue content of ET-1-LI was significantly increased 12 and 24 h after the injury. These results suggest that endogenous ET-1 is involved in astrocytic growth after spinal cord injury.
Uesugi
M
M
Department of Pharmacology, University of Tsukuba, Ibaraki, Japan.
Kasuya
Y
Y
Hama
H
H
Yamamoto
M
M
Hayashi
K
K
Masaki
T
T
Goto
K
K
D000818:Animals; D001253:Astrocytes / Q000187:drug effects*; D002455:Cell Division / Q000187:drug effects*; D019332:Endothelin-1 / Q000494:pharmacology*; D007150:Immunohistochemistry; D051381:Rats; D017208:Rats, Wistar; D013119:Spinal Cord Injuries / Q000378:metabolism*
D019332:Endothelin-1