Schiffers P M, Fazzi G E, Janssen G M, Uitendaal M P, Struijker Boudier H A, De Mey J G
Department of Pharmacology, University of Limburg, Maastricht, The Netherlands.
J Hypertens. 1994 Mar;12(3):245-50.
To compare DNA synthesis in isolated arteries of normotensive and hypertensive rats and to evaluate whether removal of the endothelium affects this process.
Carotid and renal artery segments were isolated from normotensive Wistar, Wistar-Kyoto (WKY) and Sprague-Dawley rats, and from spontaneously hypertensive rats (SHR), transgenic Sprague-Dawley rats harbouring the mouse Ren-2 gene and from WKY rats rendered hypertensive by aortic coarctation.
Artery segments were exposed in vitro to serum with or without previous gentle removal of the endothelium. Nuclear incorporation of the thymidine analogue 5-bromo-2'-deoxyuridine was visualized by immunocytochemistry and the percentage of labelled medial nuclei was determined.
In both types of artery, obtained from 6-week-old WKY rats and from 6-week-old SHR, removal of endothelium increased the percentage of 5-bromo-2'-deoxyuridine-labelled medial nuclei (L%). Also, in the arteries of 20-week-old Wistar rats, WKY rats and WKY rats rendered hypertensive by aortic coarctation and in vessels of 11-week-old Sprague-Dawley rats and Sprague-Dawley rats harbouring the mouse Ren-2 gene, removal of endothelium increased L%. Conversely, in the arteries of 20-week-old SHR removal of the endothelium did not alter L%. Furthermore, maximally stimulated DNA synthesis was considerably smaller in de-endothelialized arteries of adult SHR than in denuded vessels from the other strains and models.
These findings confirm that the endothelium can reduce DNA synthesis in the intact rat arterial smooth muscle. This effect is not modified by hypertension, but is selectively reduced in the arteries of adult SHR.
比较正常血压和高血压大鼠离体动脉中的DNA合成，并评估去除内皮是否会影响这一过程。
从正常血压的Wistar、Wistar-Kyoto（WKY）和Sprague-Dawley大鼠，以及自发性高血压大鼠（SHR）、携带小鼠Ren-2基因的转基因Sprague-Dawley大鼠和通过主动脉缩窄形成高血压的WKY大鼠中分离出颈动脉和肾动脉段。
将动脉段在体外暴露于含或不含预先轻柔去除内皮的血清中。通过免疫细胞化学观察胸苷类似物5-溴-2'-脱氧尿苷的核掺入情况，并测定标记的中层细胞核百分比。
在从6周龄WKY大鼠和6周龄SHR获得的两种类型动脉中，去除内皮均增加了5-溴-2'-脱氧尿苷标记的中层细胞核百分比（L%）。此外，在20周龄Wistar大鼠、WKY大鼠和通过主动脉缩窄形成高血压的WKY大鼠的动脉中，以及在11周龄Sprague-Dawley大鼠和携带小鼠Ren-2基因的Sprague-Dawley大鼠的血管中，去除内皮均增加了L%。相反，在20周龄SHR的动脉中，去除内皮并未改变L%。此外，成年SHR去内皮动脉中最大刺激的DNA合成明显小于其他品系和模型的去内皮血管。
这些发现证实内皮可减少完整大鼠动脉平滑肌中的DNA合成。这种作用不受高血压影响，但在成年SHR的动脉中选择性降低。
