Effects of lipopolysaccharide on the blood-brain barrier permeability in prolonged nitric oxide blockade-induced hypertensive rats
International Journal of Neuroscience, cilt.115, sa.2, ss.151-168, 2005 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 115 Sayı: 2
- Basım Tarihi: 2005
- Doi Numarası: 10.1080/00207450590519030
- Dergi Adı: International Journal of Neuroscience
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Sayfa Sayıları: ss.151-168
- Anahtar Kelimeler: Evans blue extravasation, Glial fibrillary acidic protein, L-NAME, LPS, Occludin, Zonula occludens-1
- İstanbul Yeni Yüzyıl Üniversitesi Adresli: Hayır
Özet
The authors investigated the effects of lipopolysaccharide (LPS) on the blood-brain barrier (BBB) integrity and the activity of astrocytes during the Nω-nitro-L-arginine methyl ester (L-NAME) hypertension followed by angiotensin (ANG) II in rats. They measured the changes in the BBB permeability using the Evans blue (EB) dye and concomitantly in the levels of TNF-α, IL-1β, and IL-6 in serum and nitric oxide in plasma. The authors performed two tight junction-specific proteins, zonula occludens-I and occludin, and glial fibrillary acidic protein, by using immunohistochemical method. The serum levels of TNF-α, IL-1β, IL-6, and the plasma level of nitric oxide significantly increased in LPS-treated rats (p < .01). The EB dye extravasation increased in cerebellum (p < .001) and diencephalon (p < .05) of L-NAME plus ANG II-treated animals. However, LPS reduced the increased EB dye extravasation in the brain regions of L-NAME-induced hypertensive rats treated with ANG II (p < .001). In L-NAME, there was a considerable loss of staining in both zonula occludens-I and occludin. Staining for zonula occludens-I and occludin was highly intensive in animals treated with LPS. dial flbrillary acidic protein staining was seen in a few astrocytes in brains of L-NAME-treated animals. However, this staining showed an increased intensity in the brain sections of animals treated with LPS. This study indicates that, in L-NAME hypertensive rats, ANG II leads to an increase in the extravasation of EB dye to brain as a result of decreased activity of tight junction proteins and astrocytes, and LPS could significantly attenuate the EB dye transport to the brain through the increased activity of tight junction proteins and astrocytes.