Tennant M, McGeachie J
Dental School, University of Western Australia, Nedlands, Western Australia.
Microsurgery. 1996;17(1):30-4. doi: 10.1002/(SICI)1098-2752(1996)17:1<30::AID-MICR6>3.0.CO;2-#.
This study examined the effects of raised intralumenal blood pressure on smooth muscle cell hyperplasia in the neo-intimal layer of experimental vein-to-artery grafts in rats. Autogenous vein grafts 1 mm in diameter and 4 mm long were inserted microsurgically into the left common iliac arteries of 24 genetically hypertensive (SHRSR) rats. At 2, 4, 6, 12, and 26 weeks after insertion, the grafts and contralateral unoperated iliac arteries were perfused at constant pressure and removed for histological and morphometric analyses. Neo-intimal thicknesses of the grafts and the intima-plus-media thicknesses of the contralateral arteries in the same rats were measured and compared statistically. From previous studies it is clear than in normotensive rats the neo-intima stabilises once it reaches the equivalent thickness of the contralateral arterial intima-plus-media, about 4 weeks after graft insertion. In the SHRSR rats the graft neo-intima developed at a similar rate (over the first 4 weeks) to that seen in previous studies in normotensive rats, but the development continued to occur over a longer period (6 weeks); therefore the neo-intima became significantly thicker. The graft neo-intima in SHRSR rats also became much thicker than the functionally equivalent intima-plus-media of the contralateral unoperated iliac arteries in the same rats. It was hypothesised that higher intralumenal blood pressure to SHRSR rats stimulates neo-intimal hyperplasia, resulting in the development of a thicker graft neo-intima, compared with that in normotensive rats.
本研究检测了实验性大鼠静脉-动脉移植血管新生内膜层管腔内血压升高对平滑肌细胞增生的影响。将直径1毫米、长4毫米的自体静脉移植物通过显微手术植入24只遗传性高血压大鼠（SHRSR）的左髂总动脉。植入后2周、4周、6周、12周和26周，以恒定压力灌注移植血管和对侧未手术的髂动脉，并将其取出进行组织学和形态学分析。测量同一大鼠移植血管的新生内膜厚度和对侧动脉的内膜加中膜厚度，并进行统计学比较。从先前的研究可知，在正常血压大鼠中，移植后约4周，新生内膜一旦达到对侧动脉内膜加中膜的等效厚度就会稳定下来（不再增厚）。在SHRSR大鼠中，移植血管新生内膜在前4周的发育速度与先前在正常血压大鼠中的研究相似，但发育持续时间更长（6周）；因此，新生内膜变得明显更厚。SHRSR大鼠移植血管的新生内膜也比同一大鼠对侧未手术髂动脉功能等效的内膜加中膜厚得多。据推测，与正常血压大鼠相比，SHRSR大鼠更高的管腔内血压会刺激新生内膜增生，导致移植血管新生内膜更厚。
