Black M J, Campbell J H, Campbell G R
Baker Medical Research Institute, Prahran, Australia.
Blood Vessels. 1988;25(2):89-100.
The ploidy of smooth muscle cells (SMCs) enzymatically isolated from the aorta and superior mesenteric artery (elastic arteries), caudal artery (small muscular artery) and the small mesenteric arteries and arterioles (mesenteric resistance vessels) of the spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats at ages 12, 26, 32 and 40 weeks was determined by flow cytometric DNA analysis and Feulgen-DNA photometric measurements. Frequency of polyploid cells in the aorta and superior mesenteric artery of the SHR increased from 4.43 +/- 1.35 and 7.58 +/- 1.69%, respectively, at 12 weeks to 31.26 +/- 3.00 and 14.13 +/- 1.30% at 40 weeks. There was a smaller increase in the percentage of polyploid cells in these two vessels of the WKY from 4.73 +/- 0.74 and 5.82 +/- 0.33%, respectively, at 12 weeks to 10.64 +/- 0.17 and 7.68 +/- 0.64% at 40 weeks. The caudal artery and mesenteric resistance vessels showed no significant increase in the percentage of 4N (tetraploid) cells in the SHR from 12 weeks (6.80 +/- 0.92 and 6.10 +/- 0.75%) to 40 weeks (7.83 +/- 0.67 and 7.57 +/- 0.07%). Similarly, there was no significant change in ploidy in these arteries of the WKY. Hence, while polyploidy of SMCs increases in the aorta and superior mesenteric artery of the rat with increasing age and with duration of hypertension, there is no significant change in the number of polyploid cells in smaller vessels such as the caudal artery or mesenteric resistance vessels. Since it is the resistance vessels that are involved in the development and maintenance of hypertension, polyploidy of SMCs in the blood vessel wall appears to hold little relevance to the etiology of this disease. As well, increased incidence of polyploidy is not directly attributable to increases in blood pressure as the caudal artery has a high systolic pressure in the SHR yet the incidence of polyploid cells in this artery does not differ from that of the WKY.
通过流式细胞术DNA分析和福尔根DNA光度测量法，测定了12周、26周、32周和40周龄的自发性高血压大鼠（SHR）和Wistar-Kyoto大鼠（WKY）的主动脉、肠系膜上动脉（弹性动脉）、尾动脉（小肌性动脉）以及小肠系膜动脉和小动脉（肠系膜阻力血管）中酶法分离的平滑肌细胞（SMC）的倍性。SHR的主动脉和肠系膜上动脉中多倍体细胞的频率分别从12周时的4.43±1.35%和7.58±1.69%增加到40周时的31.26±3.00%和14.13±1.30%。WKY的这两条血管中多倍体细胞百分比的增加幅度较小，分别从12周时的4.73±0.74%和5.82±0.33%增加到40周时的10.64±0.17%和7.68±0.64%。尾动脉和肠系膜阻力血管中，SHR从12周（6.80±0.92%和6.10±0.75%）到40周（7.83±0.67%和7.57±0.07%），4N（四倍体）细胞百分比没有显著增加。同样，WKY的这些动脉的倍性也没有显著变化。因此，虽然大鼠主动脉和肠系膜上动脉中SMC的多倍性随年龄增长和高血压持续时间增加，但尾动脉或肠系膜阻力血管等较小血管中的多倍体细胞数量没有显著变化。由于参与高血压发生和维持的是阻力血管，血管壁中SMC的多倍性似乎与这种疾病的病因关系不大。此外，多倍性发生率的增加并非直接归因于血压升高，因为SHR的尾动脉收缩压很高，但该动脉中多倍体细胞的发生率与WKY没有差异。
