血管内皮细胞生长因子和血管紧张素Ⅱ对蛙心包间皮、淋巴孔和心肌生血管的作用

Regulating Effects of VEGF and ANG II on the Frog's Pericardial Mesothelium, Stomata, and Angiogenesis

目的观察血管内皮细胞生长因子（ＶＥＧＦ）和血管紧张素Ⅱ（ＡＮＧⅡ）对蛙心包间皮、淋巴孔和心肌生血管的作用，探讨ＶＥＧＦ和ＡＮＧⅡ对心包间皮的通透性、淋巴孔的调控作用和心肌肥厚的影响。方法应用ＶＥＧＦ和ＡＮＧⅡ蛙腹膜腔注射，扫描电镜和光镜观察，计算机图象处理。结果正常蛙心包壁层有一些散在分布的心包淋巴孔和少量血窦状间皮。蛙心肌无血管，其血供仅由心腔内血液直接进入心肌小梁间隙。ＶＥＧＦ组和ＡＮＧⅡ组的心包淋巴孔平均直径分别为１．５０和１．７９ｕｍ，显著高于对照组的０．７２ｕｍ（Ｐ＜０．０１）；淋巴孔的平均分布密度、ＶＥＧＦ组和ＡＮＧⅡ组分别是８．２５／０．１ｍｍ２和１２．８０／０．１ｍｍ２，亦明显高于对照组的３．５７／０．１ｍｍ２（Ｐ＜０．０１）；ＶＥＧＦ组和ＡＮＧⅡ组的心包间皮血窦状结构的面积分别是２４４３．９５ｕｍ２／０．１ｍｍ２和２１２１．７９ｕｍ２／０．１ｍｍ２，明显大于对照组的９９５．０８ｕｍ２／０．１ｍｍ２（Ｐ＜０．０１）；实验组蛙心肌无新生毛细血管形成。结论ＶＥＧＦ和ＡＮＧⅡ可使蛙心包淋巴孔开放数量增多，孔径开大，分布密度增高，具明显调控心包淋巴孔的功能；另外，还能使心包间皮血窦状结构面积增多，进?

To observe the regulating effects of vascular endothelial growth factor(VEGF) and angiotensin II (ANG II ) on the frog's pericardium, lymphatic stomata, andangionesis so as to understand their influences on the mesothelial permeability, lymphaticstoma regulation, and myocardial hypertrophy. Methods VEGF and ANG II were injectedinto the frog's peritoneal cavity. The results were obtained by using LM, SEM, and computerized imaging analysis. Results Scattered distributed pericardial stomata were found onthe parietal pericardium of the frog with a few sinusoid mesothelial cells. Since there were noblood vessels in the frog's myocardium, its blood supply was directly from the cardiac chambers flowing into the trabecular spaces of the myocardium. The average diameters of the pericardial stomata in VEGF and ANG II groups were 1. 50 and 1. 79 um respectively, whichwere much larger than those in the control group (0. 72 um, P<0. 01 ). The average distribution density of the stomata was 8. 25/0. 1 mm2 and 12. 80/0. 1 mm2 in VEGF and ANG IIgroups, which was also much higher than that in the control group (3.57/0. 1 mm2, P<0. 01). The sinusoid areas in VEGF and ANG II groups were 2443. 95 um2 /0. 1 mm2 and2121. 79 um2/0. 1 mm2, which was larger than that in the control group (995. 08 um2/0.1 mm2,P<O. 01). No angionesis were found in the frogs of the experimental groups. Conclusions VEGF and ANGII strongly regulate the pericardial stomata by increasing their numbers and openings with larger diameters and higher distribution density. They can also increase the sinusoid areas with the result of the higher permeability of the pericardium, whichclealy indicated that VEGF and ANG II can speed up the material transfer of the pericardialcavity and play an important role in preventing myocardial interstitial edema. Yet there is nostrong evidence showing angionesis in the myocardium.