Kawano M, Ueno A, Ashida Y, Matsumoto N, Inoue H
Department of Biochemistry, School of Dentistry, University of Tokushima, Japan.
J Dent Res. 1992 Dec;71(12):1885-90. doi: 10.1177/00220345920710120601.
The mechanism of a sialagogue-induced increase in ornithine decarboxylase (ODC) activity and the expressions of proto-oncogenes in murine parotid gland were investigated by use of isoproterenol (IPR), carbachol (CC), and methoxamine (MTX). The results were as follows: (1) The three sialagogues had similar effects on the parotid in vivo (mouse parotid after a single injection of IPR) and/or in vitro (rat parotid explants cultured on siliconized lens paper floating on 199 medium containing IPR, CC, or MTX), the order of their effectiveness being IPR > CC > MTX. (2) Northern/dot and Western blot analyses revealed that the sialagogues elevated the steady-state levels of ODC mRNA and ODC protein to maxima at two h and six h, respectively, after stimulation. The increases were roughly proportional to those in ODC activity, suggesting that sialagogue-dependent enzyme induction is regulated at the transcriptional level. (3) The mRNAs of four of nine proto-oncogenes examined showed sialagogue-dependent increases to maxima at 30 min (c-fos) or 60 min (c-jun, c-myc, and c-src) after the beginning of stimulation. These increases were all transient, with the levels returning to the control values (without sialagogue) within 60 min. (4) The IPR-dependent elevations of ODC activity and the mRNAs of ODC, c-fos, and c-jun were inhibited by monensin, but not by polymyxin B. On the other hand, the CC-dependent increases in these parameters were inhibited by polymyxin B but not by monensin.(ABSTRACT TRUNCATED AT 250 WORDS)
通过使用异丙肾上腺素（IPR）、卡巴胆碱（CC）和甲氧明（MTX），研究了催涎剂诱导小鼠腮腺中鸟氨酸脱羧酶（ODC）活性增加以及原癌基因表达的机制。结果如下：（1）这三种催涎剂在体内（单次注射IPR后的小鼠腮腺）和/或体外（在漂浮于含IPR、CC或MTX的199培养基上的硅化镜片纸上培养的大鼠腮腺外植体）对腮腺具有相似的作用，其效力顺序为IPR > CC > MTX。（2）Northern/斑点杂交和蛋白质印迹分析表明，催涎剂刺激后，分别在2小时和6小时将ODC mRNA和ODC蛋白的稳态水平提高到最大值。这些增加与ODC活性的增加大致成比例，表明催涎剂依赖性酶诱导在转录水平受到调控。（3）在所检测的9个原癌基因中的4个的mRNA在刺激开始后30分钟（c-fos）或60分钟（c-jun、c-myc和c-src）显示出催涎剂依赖性增加至最大值。这些增加都是短暂的，60分钟内水平恢复到对照值（无催涎剂）。（4）莫能菌素抑制IPR依赖性的ODC活性以及ODC、c-fos和c-jun的mRNA升高，但多粘菌素B无此作用。另一方面，多粘菌素B抑制CC依赖性的这些参数增加，但莫能菌素无此作用。（摘要截断于250字）
