Sabbatini M, Bellagamba G, Casado A, Tayebati S K, Venarucci D, Amenta F
Dipartimento di Scienze Farmacologiche e Medicina Sperimentale, Università di Camerino, Italy.
Clin Exp Hypertens. 2001 Jan-Feb;23(1-2):143-55. doi: 10.1081/ceh-100001205.
The effect of an eight-week treatment with the Ca2+ channel blocker nicardipine on different-sized pial arteries and intracerebral arteries was assessed in spontaneously hypertensive rats (SHR) by microanatomical techniques. Normotensive Wistar-Kyoto (WKY) rats were used as normotensive reference animals. In SHR a significant increase of systolic blood pressure (SBP) in comparison with WKY rats was noticeable. An increased thickness of tunica media and luminal narrowing were also seen in medium- and small-sized pial arteries, and in intracerebral arteries of SHR in comparison with WKY rats. The media-to-lumen ratio was also increased in medium (diameter between 150 and 50 microm) and small-sized (diameter < than 50 microm) pial and intracerebral arteries. Treatment with nicardipine significantly reduced SBP, the thickness of tunica media, media-to-lumen ratio and increased luminal area of medium- and small-sized pial arteries and of intracerebral arteries. These findings demonstrate that treatment of SHR with nicardipine induces a moderate vasodilatation of both pial and intracerebral arteries regulating cerebrovascular resistance. This property may be useful in avoiding generalized or exaggerated cerebrovascular dilatation in hypertension which could be accompanied by impaired brain perfusion.
采用显微解剖技术，在自发性高血压大鼠（SHR）中评估了钙通道阻滞剂尼卡地平为期8周的治疗对不同大小软脑膜动脉和脑内动脉的影响。正常血压的Wistar-Kyoto（WKY）大鼠用作正常血压的对照动物。与WKY大鼠相比，SHR的收缩压（SBP）显著升高。与WKY大鼠相比，SHR的中小尺寸软脑膜动脉和脑内动脉的中膜厚度增加且管腔狭窄。中（直径在150至50微米之间）小尺寸（直径小于50微米）的软脑膜和脑内动脉的中膜与管腔比值也增加。尼卡地平治疗可显著降低SBP、中膜厚度、中膜与管腔比值，并增加中小尺寸软脑膜动脉和脑内动脉的管腔面积。这些发现表明，用尼卡地平治疗SHR可诱导软脑膜动脉和脑内动脉适度血管舒张，从而调节脑血管阻力。这一特性可能有助于避免高血压时出现的全身性或过度脑血管扩张，而这种扩张可能伴有脑灌注受损。
