Studies on arachidonic acid-induced brain ischemia and the difference in severity between SHRSR and WKY.
スポンサーリンク
概要
- 論文の詳細を見る
Arachidonic acid (AA) is a potent stimulator of platelet aggregation and is known to induce endothelial cell damage and edema in the brain. An ischemic cerebral infarction model can be produced in rats by an internal carotid injection of AA. In this study, water content, ATP and lactate in the brain and plasma prostaglandins (thromboxane B<SUB>2</SUB>; TXB<SUB>2</SUB> and 6-keto-prostaglandin F<SUB>1</SUB>α; 6-keto-PGF<SUB>1</SUB>α) were measured and histological observations were made after an internal carotid injection of AA in two strains of rats: stroke-resistant spontaneously hypertensive rat (SHRSR) and normotensive Wistar-Kyoto (WKY) rats. It is known that the blood pressure of the SHRSR begins to rise at about 8 weeks old.<BR>Throughout the study, AA was administered into the internal carotid artery under 2% fluothane anesthesia. In the first study, AA (1.7 mg/kg BW) was administered to 8-and 16-week-old rats and the length of survival was observed. In the second study, water content, ATP and lactate in the brain and plasma TXB<SUB>2</SUB> and 6-keto-PGF<SUB>1</SUB>α were measured 3 hours after AA (0.85 mg/kg BW) administration. In the third study, rats were perfusion-fixed 3 hours after the AA (1.7 mg/kg BW) injection and cerebral arteries were observed by scanning (SEM) and transmission electron microscope (TEM).<BR>During the 6 hour observation period, there was no difference between the two groups in the number of 8-week-old rats which survived. However, the figure became significantly lower in the SHRSR at 16 weeks old. The water content in the bilateral cerebral hemispheres was significantly larger in the SHRSR than in the WKY rats. The ATP content of the region was significantly less in the SHRSR than in the WKY rats. The lactate content in the frontal region was significantly larger in the SHRSR than in the WKY rats, but there were no differences between the two strains in the occipital region. Prior to AA administration, there were no differences in plasma TXB<SUB>2</SUB> and 6-keto-PGF<SUB>1</SUB>α levels of the two strains. After the AA injection, the magnitude of plasma prostaglandin elevations was significantly larger in the SHRSR than in the WKY rats. Upon SEM examination, the luminal surfaces of the middle cerebral arteries and intracerebral arterioles revealed endothelial damage and thrombi formations were more prevalent in the SHRSR than in the WKY rats. TEM observations of the cerebral cortex revealed that the extent of perivascular edema and diffusely destroyed luminal unit membrane of the capillary endothelium were more severe in the SHRSR than in the WKY rats.<BR>These results show that the AA metabolism and the responses to injected AA in platelets and cerebrovascular endothelial cells differ between SHRSR and WKY rats. These differences may contribute to severity of cerebral ischemia in SHRSR. The development of hypertension in SHRSR may be related to the differences in the AA metabolism of the two strains.
- 日本医科大学医学会の論文
日本医科大学医学会 | 論文
- わが国における腸チフスの疫学的考察--1973年〜1976年届出菌検出例を中心として
- 臨床および実験報告 二絨毛膜双胎妊娠における高年初産の検討
- 救急災害医学の確立と展望[含 略歴 研究業績] (定年退職教授記念講演会講演要旨)
- 臨床のために 関節リウマチの診断と治療
- TNFファミリーの制御による関節リウマチ治療の可能性 (特集 第15回公開「シンポジウム」(アレルギー・膠原病に対する新たな展開))