5-氨基乙酰丙酸介导光动力治疗大鼠甲状旁腺功能亢进的实验研究

发布时间：2018-05-02 12:37

本文选题：5-氨基乙酰丙酸 + 光动力治疗　；参考：《第三军医大学》2015年硕士论文

【摘要】：背景与目的甲状旁腺功能亢进症(hyperparathyroidism)一般分为原发性(Primary hyperparathyroidism,PHPT)、继发性(secondary hyperparathyroidism,SHPT)、三发性(tertiary hyperparathyroidism,3HPT)三种类型,其共同特征是甲状旁腺激素(parathyroid hormone,PTH)的合成和分泌过多。对大部分继发于甲状旁腺(parathyroid gland,PTG)增生所致的甲状旁腺功能亢进症来说,其治疗以甲状旁腺切除术(parathyroidectomy)最为有效。手术治疗往往需要比较严格的适应症或部分患者不愿意接受手术而使其应用受到限制。对于多发或非典型腺瘤者,术中被遗漏或切除相对不足等时有发生,而切除过多则可导致术后持久性的低钙血症,甚至发生永久性甲状旁腺功能减低(hypoparathyroidism)的可能。近年来发展起来的微创手术,虽然具有创伤性小、耐受性好、术后甲旁减发生率低等优点,但其适应人群仅限于单个腺瘤的患者。光动力治疗(photodynamic therapy,PDT)是近年来兴起的一种基于光化学反应的新疗法。其基本原理是利用光敏剂在某些特定组织中的差异性高浓度蓄积,在氧的存在下,经特定波长(630nm)光的照射后,生成活性氧(reactive oxygen species,ROS),进而产生一系列氧化产物诱导细胞死亡,从而达到治疗肿瘤等病变组织的目的。其相比于传统手术、放疗或化疗,具有适应症广、特异性高、副作用少等优点,目前已广泛应用于各种肿瘤、皮肤病、甚至感染性疾病的治疗当中。已有研究表明,将光敏剂5-氨基乙酰丙酸(5-aminolevulinic acid,5-ALA)注射入大鼠或人体内后,其中间代谢产物原卟啉IX(Protoporphyrin IX,Pp IX)(光敏物质)在正常或增生的甲状旁腺组织中具有与周围组织相比更高浓度的蓄积。但是否能产生光动力效应,目前仍不清楚。本研究旨在分析5-ALA介导PpIX在大鼠甲状旁腺及其周围组织当中的分布特点,明确5-ALA所介导的光动力疗法(5-ALA PDT)作用于正常大鼠甲状旁腺的安全性与有效性,并尝试将5-ALA PDT应用于继发性甲状旁腺功能亢进症(SHPT)大鼠模型的治疗中。方法1、将5-ALA注射入大鼠腹腔后切取甲状旁腺(PTG)、甲状腺(TG)及周围肌肉组织,分别测定其内的Pp IX浓度进行比较,同时明确Pp IX浓度与5-ALA注射剂量及作用时间之间的关系;2、按光敏剂剂量和光照时间进行随机分组,手术暴露PTG及其周围组织后行光动力照射,检测照射前后血清甲状旁腺激素(PTH)、总钙(Ca)、三碘甲状腺原氨酸(T3)、甲状腺素(T4)、促甲状腺素(TSH)水平,并观察各组织形态学上的变化。3、通过5/6肾切除结合高磷饲养制备SHPT大鼠模型后分多次对其行PDT照射,并比较每次照射前后血清PTH水平的变化。结果1、在各时间点上检测到PTG内PpIX浓度均高于TG及周围肌肉组织(p0.05);PTG内PpIX浓度随5-ALA作用时间逐渐升高,在1.5h检测到最大值(77.38±8.92)ug/g,之后开始逐渐下降,PTG内Pp IX浓度随5-ALA注射剂量增加而逐渐升高(p0.05),当5-ALA注射剂量由400mg/kg增加到600mg/kg时,PTG内PpIX含量仍有所上升,但差异已无统计学意义(p0.05);2、单独使用光敏剂或光照对PTG功能无影响,在PDT照射0.25d后即检测到血清PTH、总Ca显著下降(p0.05),而照射前后血清T3、T4、TSH始终无明显改变(p0.05)。PDT照射后血清PTH水平随5-ALA注射剂量的增加、光照时间延长而降低,与对照组(0mg/kg,0min)相比差异显著(p0.05);组织学检查显示PDT照射后PTG组织包膜仍完整,但主细胞明显减少,脂肪细胞增多,TG与周围肌肉组织未见到明显变化。3、5/6肾切除结合高磷饲养28天后大鼠血清Cr、PTH水平明显高于手术前(p0.05),SHPT模型大鼠经多次PDT照射后的血清PTH水平随照射次数的增加而降低,经PDT(100mg/kg,10min)照射3次后的PTH水平与手术前比较已无显著差异(p0.05)。结论1、5-ALA介导PpIX在大鼠PTG内的蓄积浓度明显高于周围组织,并与5-ALA注射剂量及作用时间相关;2、5-ALA PDT可对正常大鼠PTG的组织形态和功能产生特异性破坏作用,有效性、安全性良好;3、5-ALA PDT对SHPT模型大鼠的治疗效果明显,多次照射疗效可叠加。
[Abstract]:Background and objective hyperparathyroidism (hyperparathyroidism) is generally divided into three types, primary (Primary hyperparathyroidism, PHPT), secondary (secondary hyperparathyroidism, SHPT), and three types of tertiary hyperparathyroidism (3HPT). The common feature is the synthesis and differentiation of parathyroid hormone (parathyroid hormone). Hyperparathyroidism is the most effective treatment for most hyperparathyroidism secondary to hyperparathyroid (parathyroid gland, PTG) hyperplasia. Surgical treatment often requires stricter indications or some patients are not willing to undergo surgery to restrict their application. Patients with multiple or atypical adenomas may be missed or excised during operation, and excision may lead to postoperative persistent hypocalcemia, or even permanent hypoparathyroidism (hypoparathyroidism). The minimally invasive surgery in recent years has a small traumatic, tolerable tolerance, and a postoperative one. Photodynamic therapy (PDT) is a new therapy based on photochemical reaction in recent years. The basic principle is to use photosensitizer to accumulate differential high concentration in certain tissues, in the presence of oxygen, by specific wavelengths ( 630nm) after light irradiation, it generates active oxygen (reactive oxygen species, ROS), and then produces a series of oxidation products to induce cell death, thus achieving the purpose of treating tumor and other pathological tissues. Compared with traditional surgery, radiotherapy or chemotherapy, it has many advantages, such as wide adaptation, high specificity, less side effects and so on. It has been widely used in various kinds of tumors at present. In the treatment of dermatoses and even infectious diseases, studies have shown that the photosensitizer 5- aminolevulinic acid (5-aminolevulinic acid, 5-ALA) is injected into the rat or human body, in which the metabolic product protoporphyrin IX (Protoporphyrin IX, Pp IX) is compared with the surrounding tissue in normal or hyperplastic parathyroid tissue. The aim of this study is to analyze the distribution characteristics of 5-ALA mediated PpIX in the parathyroid and surrounding tissues of rats, and to clarify the safety and effectiveness of 5-ALA mediated photodynamic therapy (5-ALA PDT) in the parathyroid glands of normal rats and try to make 5-ALA PD. T was used in the treatment of rat model of secondary hyperparathyroidism (SHPT). Method 1, the 5-ALA was injected into the abdominal cavity of the rat and the parathyroid gland (PTG), the thyroid (TG) and the surrounding muscle tissue were measured. The concentration of Pp IX in the rat was compared. At the same time, the relationship between the IX concentration of Pp and the dose of 5-ALA and the time of action and the time of action were determined. 2, According to the dose of photosensitizer and light time, the PTG and its surrounding tissue were exposed to photodynamic irradiation. The serum parathyroid hormone (PTH), total calcium (Ca), three iodine thyroxine (T3), thyroxine (T4) and thyrotropin (TSH) were detected before and after irradiation, and the morphological changes of each tissue were observed and.3 was observed by 5/6 nephrectomy. The SHPT rat model was irradiated with PDT with high phosphorus feeding, and the changes of serum PTH level before and after each time were compared. Results 1, the concentration of PpIX in PTG was higher than TG and the surrounding muscle tissue (P0.05) at each time point. The concentration of PpIX in PTG increased with the 5-ALA action time, and the maximum value (77.38 + 8.9) was detected in 1.5h. 2) ug/g, then began to decrease gradually, and the concentration of Pp IX in PTG gradually increased with the increase of 5-ALA injection dose (P0.05). When 5-ALA injection dose increased from 400mg/kg to 600mg/kg, PpIX content in PTG was still up, but the difference had no statistical significance (P0.05). Serum PTH, total Ca decreased significantly (P0.05), but the serum T3, T4, TSH before and after irradiation had no significant changes (P0.05).PDT irradiation, the serum PTH levels were increased with the increase of 5-ALA injection dose and light time prolonged, compared with the control group (0mg/kg, 0min). But the main cells decreased obviously, the fat cells increased, and the TG and the surrounding muscle tissue did not see obvious changes in the serum Cr, PTH level was significantly higher than that before the operation (P0.05) after 28 days of.3,5/6 nephrectomy combined with high phosphorus. The serum PTH level of SHPT model rats decreased with the increase of the number of shots after PDT irradiation, and was irradiated by PDT (100mg/kg, 10min). There was no significant difference in the level of PTH after 3 times (P0.05). Conclusion the accumulation of PpIX in PTG was significantly higher than that of peripheral tissue, and it was related to the dose and time of 5-ALA injection; 2,5-ALA PDT could produce specific damage to the morphology and function of PTG in normal rats. The effectiveness and safety of 2,5-ALA PDT were good; 3,5 is good. 3,5 The effect of -ALA PDT on SHPT model rats was obvious, and the effect of multiple irradiation could be superposed.

【学位授予单位】：第三军医大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R582.1

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