PRODUCTION OF BOTH PROLACTIN AND GROWTH HORMONE BY CLONAL STRAINS OF RAT PITUITARY TUMOR CELLS
PRODUCTION OF BOTH PROLACTIN AND GROWTH HORMONE BY CLONAL STRAINS OF RAT PITUITARY TUMOR CELLS
复制标题
大鼠垂体肿瘤细胞克隆株产生催乳素和生长激素
作者：
A. Tashjian;F. Bancroft;L. Levine
几种已建立的大鼠垂体细胞克隆株在培养中产生生长激素，已显示出分泌第二种蛋白质激素，催乳素。用补体固定法在培养基和细胞内免疫测定催乳素。在四种不同的细胞株中，催乳素的产率从每24小时6.6µg/mg细胞蛋白到12µg/mg细胞蛋白不等。在这些培养中，催乳素与生长激素的比值从1.0到4.1不等。第五个克隆株产生生长激素，但没有检测到催乳素。细胞内催乳素相当于在1-2小时内分泌到培养基中的量。环己亚胺和嘌呤霉素抑制催乳素的产生至少94%。氢化可的松（3 × 10-6 M）在大多数细胞株中刺激生长激素的产生4- 8倍，使催乳素的产生率降低到对照培养的25%以下。相反，在所有菌株的培养基中加入包括下丘脑在内的几种组织的简单酸提取物，催乳素的产生率提高了6至9倍，生长激素的产生率降低了约50%。我们的结论是，培养的多功能大鼠垂体细胞为进一步研究哺乳动物细胞中器官特异性活性的表达控制提供了不寻常的希望。
Several established clonal strains of rat pituitary cells which produce growth hormone in culture have been shown to secrete a second protein hormone, prolactin. Prolactin was measured immunologically in culture medium and within cells by complement fixation. Rates of prolactin production varied from 6.6 to 12 µg/mg cell protein per 24 hr in four different cell strains. In these cultures ratios of production of prolactin to growth hormone varied from 1.0 to 4.1. A fifth clonal strain produced growth hormone but no detectable prolactin. Intracellular prolactin was equivalent to the amount secreted into medium in a period of about 1–2 hr. Both cycloheximide and puromycin suppressed prolactin production by at least 94%. Hydrocortisone (3 x 10-6 M), which stimulated the production of growth hormone 4- to 8-fold in most of the cell strains, reduced the rate of prolactin production to less than 25% of that in control cultures. Conversely, addition of simple acid extracts of several tissues, including hypothalamus, to the medium of all strains increased the rate of production of prolactin six to nine times and decreased growth hormone production by about 50%. We conclude that multifunctional rat pituitary cells in culture show unusual promise for further studies of the control of expression of organ-specific activities in mammalian cells.