BQ788, an endothelin ETB receptor antagonist, attenuates stab wound injury-induced reactive astrocytes in rat brain
✍ Scribed by Yutaka Koyama; Motohide Takemura; Keiko Fujiki; Nobue Ishikawa; Yoshio Shigenaga; Akemichi Baba
- Book ID
- 101263944
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 104 KB
- Volume
- 26
- Category
- Article
- ISSN
- 0894-1491
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✦ Synopsis
Endothelins (ETs) are suggested to be involved in pathological or pathophysiological responses on brain injuries. In the present study, an involvement of ETs on activation of astrocytes in vivo was examined by using selective endothelin receptor antagonists. A stab wound injury on rat cerebral cortex increased immunoreactive ET-1 at the injured site. GFAP-positive [GFAP(ϩ)] and vimentin-positive [Vim(ϩ)] cells appeared at the injured site in 1 day to 2 weeks after the injury. A continuous infusion of BQ788, a selective ET B receptor antagonist, into cerebral ventricle (23 nmole/day) attenuated increase in the numbers of GFAP(ϩ) and Vim(ϩ) cells after the injury. FR139317, a selective ET A antagonist (23 nmole/day), slightly decreased the number of Vim(ϩ) cells but not that of GFAP(ϩ) cells. Increase in the number of microglia/macrophages by a stab wound injury, which was determined by Griffonia simplicifolia isolectin B 4 staining, was not affected by BQ788 and FR139317. These results suggest that activation of glial ET B receptors is one of the signal cascades leading to reactive astrocytes on brain injuries.