中文摘要：

目的：研究光动力学疗法对动物肿瘤生长的影响及生长抑素（somatostantin，SS）、ghrelin表达的变化。方法：选用皮下接种W256瘤细胞株制成实验性荷瘤大鼠，观察经紫外光照射、充氧并加注血卟啉的血液对大鼠移植肿瘤生长的影响，同时采用放射免疫检测方法观察血浆、组织中SS含量的改变；采用实时PCR和免疫荧光组化方法观察了ghrelinm RNA和ghrelin在脑内表达的影响。结果：荷瘤大鼠输入经紫外光照射、充氧并加注血卟啉的血液，其肿瘤生长速度明显减慢，肿瘤重量明显减轻（P〈0．01）。荷瘤大鼠下丘脑、中脑、桥延脑、肝脏、瘤组织及血浆SS含量与正常大鼠比较显著增加（P〈0．05），下丘脑、垂体ghrelin mRNA表达显著减少，同时下丘脑弓状核（Are）内ghrelin免疫阳性细胞显著减少（P〈0．01），但经光动力学疗法治疗肿瘤后，上述各组织和血浆中SS含量明显下降（P〈0．01），下丘脑、垂体ghrelin mRNA含量和下丘脑弓状核内ghrelin免疫阳性细胞数量均显著增加（P〈0．05）。结论：光动力学疗法对肿瘤生长有抑制作用；肿瘤生长过程中激活某种途径刺激机体产生生长抑素以提高机体抵抗肿瘤生长的能力，同时ghrelin也参与了肿瘤的发生和发展。

英文摘要：

Objective：To study the effects of photodynamic therapy （PDT） on the growth of transplanted tumors and the changes of ghrelin and somatostatin （SS） in this process. Methods：Experimental tumor-bearing rat model was established by injecting W256 tumor cells subcutaneously into the rat＇s groin. The rats were transfused with ultraviolet-irradiated,oxygenated, and hematoporphyriwsupplemented blood. The effect of PDT on the growth of transplanted tumor was observed. The contents of SS in plasma and tissues were detected by radioimmunoassay （RIA）. Expression of ghrelin mRNA in hypothalamus and pituitary was measured by real time polymerase chain reaction. The expression of ghrelin protein in neurons was observed by fluorescence immunohistochemical staining. Results： Tumor-bearing rats showed slow tumor growth and reduced tumor weights after PDT（P〈0.01）. The contents of SS in hypothalamus, midbrain, pons and medulla, liver, tumor tissue, and plasma were significantly increased in tumor-bearing rats compared with control rats（P〈0.05）. The expressions of ghrelin mRNA in hypothalamus and pituitary as well as the number of ghrelin positive neurons in arcuate nucleus （Arc） were significantly reduced （P〈0.01）. However the contents of SS in the brain and tumor tissues and plasma were significantly decreased（P〈0.01） and the expression of ghrelin mRNA and the number of ghrelin-positive neurons were increased after PDT（P〈0.05）. Conclusion：PDT inhibits the growth of tumor. SS and ghrelin were involved in the processes of tumor genesis and development.