Ishizuka T, Niwa A, Tabuchi M, Nagatani Y, Ooshima K, Higashino H. Involvement of thromboxane A2 receptor in the cerebrovascular damage of salt-loaded, stroke-prone rats.
J Hypertens 2007;
25:861-70. [PMID:
17351380 DOI:
10.1097/hjh.0b013e3280464dc8]
[Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND
Inflammatory processes may play a pivotal role in the pathogenesis of cerebrovascular injury in salt-loaded, stroke-prone, spontaneously hypertensive rats (SHRSP). Thromboxane A2 (TP) receptor stimulation by 8-iso-prostaglandin F2alpha (8-iso-PGF2alpha) is involved in the process of vascular inflammation.
OBJECTIVE
In the present study, we examined the involvement of TP receptor in the development of cerebrovascular damage in salt-loaded SHRSP.
METHODS
Nine-week-old SHRSP were fed a 0.4% NaCl or a 4% NaCl diet with or without ONO-8809 treatment (a TP receptor antagonist) for 5 weeks. Blood pressure, mortality, and the parameters of cerebrovascular inflammation and damage were compared between the groups. Moreover, we examined the effect of 8-iso-PGF2alpha infusion on cerebrovascular injury of SHRSP.
RESULTS
High salt intake in SHRSP significantly increased blood-brain barrier impairment and early mortality, which were suppressed by ONO-8809 treatment independent of changes in blood pressure. Salt loading also significantly increased superoxide production in basilar arteries of SHRSP, which was suppressed by ONO-8809 treatment. Macrophage accumulation and matrix metalloproteinase-9 (MMP-9) activity in the stroke-negative area in the contralateral cerebral cortex to the stroke lesion of salt-loaded SHRSP and 8-iso-PGF2alpha-treated SHRSP were significantly reduced by ONO-8809 treatment. The ONO-8809 treatment prevented thinning of the vessel layer in cerebral arterioles of salt-loaded SHRSP and 8-iso-PGF2alpha-treated SHRSP.
CONCLUSIONS
These results suggest that TP receptor stimulation by 8-iso-PGF2alpha may involve salt loading-induced stroke through activation of cerebrovascular inflammation and damage.
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