四氢叶酸钙对大剂量甲氨蝶呤化疗大鼠肠黏膜保护作用的研究

Study of calcium 5-formyltetrahydrofolate protection enteral mucosa after chemotherapy of high-dose methotrexate in rats

目的探讨不同剂量和时间四氢叶酸钙(calcium5-formyltetrahydrofolate,CF)对大剂量甲氨蝶呤(high-dose methotrexate,HDMTX)化疗大鼠肠黏膜的保护作用。方法实验分两部分,均分5组,设正常对照组(A组,腹腔注射生理盐水),和空白对照组(B组,腹腔注射MTX,不予CF解救)。第一部分:不同剂量CF对HDMTX化疗大鼠肠黏膜的保护作用。C组:1%CF解救组;D组:2%CF解救组;E组:8%CF解救组(百分数为CF总量占MTX的百分比)。C、D、E组腹腔注射MTX,于注射后12h肌注CF,A、B组肌注生理盐水,6小时一次,共7次。第二部分:不同时间CF对HDMTX化疗入鼠肠黏膜的保护作用,C组:12h解救组;D组:24h解救组;E组:30h解救组。C、D、E组腹腔注射MTX。C、D、E组分别于腹腔注射HDMTX后12、24、30h予肌注CF,CF总剂量为MTX的5%;A、B组于腹腔注射后24h分别肌注生理盐水,各组均6小时一次,共7次。于腹腔注射后78h处死存活大鼠,取空肠标本观察形态,测定绒毛长度和隐窝深度。结果两部分均A组肠壁厚弹性好,绒毛密集、排列整齐,B、C、D、E组肠壁充血水肿变薄,和A组比较,小肠绒毛变短,隐窝深度变浅,差异有统计学意义(P<0.05);第一部分B、C组改变较D、E组更明显(P<0.05);C组与B组比较差异无统计学意义(P>0.05);D组与E组比较差异无统计学意义(P>0.05)。第二部分B、E组改变较C、D组更显著(P<0.05);B组与E组比较差异无统计学意义(P>0.05);C组与D组比较差异无统计学意义(P>0.05)。结论CF对HDMTX所致大鼠肠黏膜损害有保护作用;其保护作用存在剂量和时间依赖性。

Objective Evaluation of calcium 5-formyltetrahydrofolate（CF） protecting enteral mucosa of rats with different doses and at different time after high-dose methotrexate（HDMTX） used. Methods The first part： six-week-old Wister rats were divided into 5 groups in random, twety rats every group. Group A： normal control; Group B： blank control; Group C： 1% CF; Group D： 2% CF; Group E： 8% CF. After the rats were intraperitoneal injected with NS for group A, HDMTX（ 120 mg/g） for groups B-E 12 hours, NS was intramuscular injected for group A and B, 1% CF （total CF dose amounts to 1% of MTX dose） for group C, 2% CF for group D, 8% CF for Group E, q6h ×7 times. Rats were killed after intraperitoneal injection 78 hours. Morphous of jejunum dissection was observed, length of intestinal villus and depth of crypt were measured. The second part： six-week-old Wister rats were divided randomly into 5 groups ,twenty rats in every group. Group A： normal control; Group B： blank control;Group C：12 h CF; Group D：24 h CF; Group E： 30h CF. The rats were intraperitoneal injected with NS for group A, HDMTX（ 120 mg/g） for groups B-E. After intraperitoneal injection 24h, NS was intramuscular injected for group A and B, CF （ total CF dose amounts to 5% of MTX dose） for group C , D, E after intraperitoneal injection 12, 24 and 30 hours respectively. Rats were killed after HDMTX injected 78 hours. Morphous of jejunum dissection were observed, length of intestinal villus and depth of crypt were measured. Results The first part： in group A, jejunum walls were thick and elastic , intestinal villus were close and orderly. Jejunum wails were congestive, swollen and thin in group B, C, D and E. The length of intestinal villus was 101.00 2. 00 μm in group A, 26.2±4.50μm in group B, 28.43± 8.28μm in group C, 59.06 ±12.35 μm in group D, 57.90 ± 13.10 μm in group E. The depth of crypt was 17.25±0. 85 μm in group A, 0.38 ± 0. 09 μm in group B, 0.83 ± 1.11 μm in group C, 6.28 ± 1.29 μm in group D, 5.90± 1.02 μm in group E. The length of intestinal villus and the depth of crypt were reduced significantly in group B,C, D and E（P 〈0. 05 vs group A）. In group B and C,they were shorter than that in group D and E（P 〈0. 05）. They had no significant difference between group B and C（P 〉0. 05）, and no significant differenee between group D and E （ P 〉 0. 05 ）, too. The second part ： in group A, jejunum walls were thick and elastic ,intestinal villus were close and orderly. Jejunum walls were congestive, swollen and thin in group B , C, D and E. The length of intestinal villus was 145.00 ± 5.56 μm in group A, 33.04±4.43 μm in group B, 63.92 ±2. 97 in group C, 52.56±4.61 μm in group D, 37. 52± 6. 10 μm in group E. The depth of crypt was 16.92 ~ 1.29 μm in group A, 0.36 ±0. 14 μm in group B, 6. 96±0.75 μm in group C, 0. 84 ±0. 81 μm in group D, 0.42±0. 22 μm in group E. The length of intestinal villus and depth of crypt were shorter in group B, C, D and E than that in group A （P 〈0. 05）. In group B and E,they were shorter than that in group C and D（P 〈0. 05）. They had no significant difference between group B and E （P 〉 0. 05 ）, and no significant difference between group C and D （ P 〉 0. 05 ） , too. Conclusion CF could protect the damage of enteral mucosa of rat caused by HDMTX. The characteristic of this function is dose-depend and time-depend.