五味子油对链脲佐菌素诱导的2型糖尿病大鼠的影响

Effect of Schisandrae Fructus oil on type 2 diabetic rats induced by Streptozotocin

目的研究五味子油对链脲佐菌素诱导的2型糖尿病大鼠血糖、胰岛细胞形态及功能影响。方法高脂饲料联合2次ip小剂量链脲佐菌素(STZ)诱导建立2型糖尿病大鼠模型。糖尿病大鼠每天分别ig五味子油0.25、0.5、1.0 mg/kg,连续给药6周后检测大鼠空腹血糖、血清胰岛素水平;HE染色法观察大鼠胰腺病理形态学改变;免疫组织化学方法检测大鼠胰腺细胞胰岛素的表达;RT-PCR法检测大鼠胰腺组织胰岛素和胰十二指肠同源盒因子(PDX-1)mRNA表达水平。结果五味子油可显著降低糖尿病大鼠的血糖水平,其高剂量组可使血糖恢复至正常水平;提高胰岛素分泌水平,显著提高胰岛素敏感指数,改善胰岛素抵抗;可减轻糖尿病大鼠胰腺病理学改变,使变小的胰岛体积增大、胰岛β细胞数目增多、胰岛素表达提高;还可提高糖尿病大鼠胰腺组织胰岛素和PDX-1 mRNA表达水平。结论五味子油可以改善2型糖尿病大鼠胰岛素抵抗,减轻胰岛β细胞的损伤,增加β细胞数量,改善β细胞的功能缺陷,提高胰岛素的分泌量,增加胰岛素和PDX-1 mRNA表达,从而产生降血糖作用。

Objective In the present study,our information from Senecio scandens full-length cDNA clones will serve as a useful resource for elucidating functional genes and will also aid a precise annotation of genomics in Compositae plants.Methods The total RNA was extracted from S.scandens using Trizol method.SMART（switching mechanism at 5’ end of RNA transcript） was applied to constructing the full-length cDNA library.Titer of the library,full-length ratio,and redundancy rate for 600 monoclone randomly selected sequencing library were evaluated by PCR amplification.NCBI and COG database was used to compare those sequences.Results Parameters of the the quality of cDNA library were as follows： the capacity of the library（4.3×106cfu/mL）,the average size of the inserted fragment（1.7 kb）,the recombination rate（96.35%）,the full-length rate（58.24%）,and the redundancy rate（10.88%）.EST sequences for 524 full-length were obtained in this study,involving 467 unigenes,among which five sequences associated with synthesis,transport,and metabolism of S.scandens secondary metabolites.Conclusion SMART technology could be effectively applied to constructing the full-length cDNA library of S.scandens.Our results indicate that the full-length cDNA library could be further applied to regulation of expression on identification of functional genome,screening of novel genes,and biosynthesis of metabolism genes in S.scandens.