Hixenbaugh E A, Strauss J F, Paavola L G
Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140.
Anat Rec. 1993 Apr;235(4):487-500. doi: 10.1002/ar.1092350402.
We used biochemical and structural approaches to analyze the influence of gonadotropic hormones on the association of hepatic lipase with specific subsets of ovarian blood vessels. Western blotting was used to detect this enzyme in effluent collected from heparin-perfused ovaries of nonhormone-treated immature rats and those primed with pregnant mare's serum gonadotropin (PMSG) alone or in combination with human chorionic gonadotropin (hCG). The effects of these hormones on hepatic lipase distribution among ovarian blood vessels was assessed before and after hCG and/or PMSG treatment by immunofluorescence and immunogold cytochemistry. For the latter, immunoreagents and fixative were delivered directly to chilled, unfixed ovaries by in situ vascular perfusion. Data from biochemical and structural analyses indicated that hepatic lipase was absent from nonhormone-treated ovaries. As shown by Western blotting of ovarian effluent, the enzyme appeared following treatment with PMSG and PMSG-hCG; it increased in amount in a time-dependent manner, with a transient decline in the early hours after hCG injection. Enzyme levels paralleled growth and vascularization of follicles and corpora lutea; the fall tended to coincide with early events in luteal angiogenesis. Immunogold microscopy showed that hepatic lipase was abundant in thin-walled blood vessels of theca interna of follicles, corpora lutea, and interstitial cells but sparse in those of the stroma. Moreover, during neovascularization of differentiating corpora lutea, vascular sprouts arising from hepatic lipase-laden thecal vessels appeared to lose, then regain, the enzyme as development progressed. Our findings thus suggest 1) that hormones influence the establishment of endothelial cell heterogeneity within the microvasculature of a single organ and 2) that development of novel endothelial cell properties in specific subsets of blood vessels underlies compartmentalization of function within a tissue.
我们采用生化和结构方法来分析促性腺激素对肝脂肪酶与卵巢特定血管亚群结合的影响。利用蛋白质免疫印迹法检测从未用激素处理的未成熟大鼠以及仅用孕马血清促性腺激素（PMSG）或与人类绒毛膜促性腺激素（hCG）联合处理的未成熟大鼠经肝素灌注的卵巢中收集的流出液中的这种酶。通过免疫荧光和免疫金细胞化学方法评估这些激素在hCG和/或PMSG处理前后对肝脂肪酶在卵巢血管中分布的影响。对于后者，通过原位血管灌注将免疫试剂和固定剂直接输送到冷冻的、未固定的卵巢。生化和结构分析的数据表明，未用激素处理的卵巢中不存在肝脂肪酶。如卵巢流出液的蛋白质免疫印迹所示，在用PMSG和PMSG - hCG处理后该酶出现；其含量呈时间依赖性增加，在注射hCG后的早期有短暂下降。酶水平与卵泡和黄体的生长及血管形成平行；下降趋势往往与黄体血管生成的早期事件相吻合。免疫金显微镜检查显示，肝脂肪酶在卵泡内膜、黄体和间质细胞的薄壁血管中丰富，但在基质血管中稀少。此外，在分化中的黄体的新生血管形成过程中，来自富含肝脂肪酶的卵泡膜血管的血管芽在发育过程中似乎先失去该酶，然后又重新获得。因此，我们的研究结果表明：1）激素影响单个器官微血管内内皮细胞异质性的建立；2）特定血管亚群中新型内皮细胞特性的发育是组织内功能区室化的基础。
