White B A, Bauerle L R, Bancroft F C
J Biol Chem. 1981 Jun 25;256(12):5942-5.
Addition of CaCl2 (0.4 mM) to GH3 cells incubated in a serum-free, Ca2+-free medium increased relative prolactin synthesis (prolactin synthesis/total protein synthesis) 7- to 150-fold by 3-4 days, but had no effect on relative growth hormone synthesis. Half-maximal and maximal stimulation of relative prolactin synthesis occurred at about 0.07 and 0.2 mM CaCl2, respectively. Neither MgCl2 (0.4 mM) nor KCl 0.4 mM) affected relative prolactin synthesis. 32P-labeled rat prolactin and growth hormone cDNA plasmids were employed to measure by RNA gel blot hybridization changes in cytoplasmic levels of the corresponding mRNA sequences. Both prolactin mRNA sequence levels and translatable prolactin mRNA increased in parallel with the CaCl2-induced increase in relative prolactin synthesis. CaCl2 increased prolactin mRNA sequences by 7- to 200-fold, without affecting growth hormone mRNA sequence levels. Dexamethasone (100 nM) decreased prolactin mRNA sequences in cells incubated with CaCl2, antagonized the CaCl2-induced increases in prolactin mRNA sequences independently of the CaCl2 concentration.
向在无血清、无钙培养基中培养的GH3细胞添加氯化钙（0.4 mM），3至4天内相对催乳素合成（催乳素合成/总蛋白合成）增加了7至150倍，但对相对生长激素合成没有影响。相对催乳素合成的半最大刺激和最大刺激分别出现在约0.07 mM和0.2 mM氯化钙时。氯化镁（0.4 mM）和氯化钾（0.4 mM）均不影响相对催乳素合成。用32P标记的大鼠催乳素和生长激素cDNA质粒通过RNA凝胶印迹杂交法测量相应mRNA序列的细胞质水平变化。催乳素mRNA序列水平和可翻译的催乳素mRNA均与氯化钙诱导的相对催乳素合成增加平行升高。氯化钙使催乳素mRNA序列增加了7至200倍，而不影响生长激素mRNA序列水平。地塞米松（100 nM）降低了与氯化钙一起培养的细胞中的催乳素mRNA序列，且与氯化钙浓度无关，拮抗了氯化钙诱导的催乳素mRNA序列增加。
