McPherson M A, Ramachandran J
J Cell Biol. 1980 Jul;86(1):129-34. doi: 10.1083/jcb.86.1.129.
ACTH inhibits DNA synthesis in normal rat and mouse tumor Y-1 adrenocortical cells within the same concentration range that it stimulates steroidogenesis. These processes can be independently regulated as demonstrated by the divergent actions of cytochalasin B on these cells. In the normal cells, cytochalasin B does not increase steroidogenesis in serum-free or serum-containing media, and it decreases the stimulation produced by ACTH. In the absence of serum, the Y-1 cells respond in a similar way. However, in serum-containing media, cytochalasin B increases steroidogenesis in these cells and does not inhibit the response to ACTH. In both cell types, cytochalasin B inhibits [3H]thymidine incorporation into DNA by a mechanism different than that of ACTH. In the Y-1 cells, this inhibition is caused by a decreased uptake of [3H]thymidine into the cell, which probably reflects a decreased transport across the cell membrane. In the normal cells, cytochalasin B, like ACTH, does not affect [3H]thymidine transport, but it decreases DNA synthesis much more rapidly than does ACTH. This inhibition may be the result of the disruption of microfilaments by cytochalasinB, because our evidence indicates that it is not caused by a decrease in glucose uptake by the cells.
促肾上腺皮质激素（ACTH）在刺激类固醇生成的相同浓度范围内，抑制正常大鼠和小鼠肿瘤Y - 1肾上腺皮质细胞中的DNA合成。正如细胞松弛素B对这些细胞的不同作用所表明的，这些过程可以独立调节。在正常细胞中，细胞松弛素B在无血清或含血清培养基中均不会增加类固醇生成，并且会降低ACTH所产生的刺激作用。在无血清的情况下，Y - 1细胞的反应类似。然而，在含血清的培养基中，细胞松弛素B会增加这些细胞中的类固醇生成，并且不会抑制对ACTH的反应。在这两种细胞类型中，细胞松弛素B通过一种不同于ACTH的机制抑制[3H]胸腺嘧啶核苷掺入DNA。在Y - 1细胞中，这种抑制是由于[3H]胸腺嘧啶核苷进入细胞的摄取减少所致，这可能反映了跨细胞膜转运的减少。在正常细胞中，细胞松弛素B与ACTH一样，不影响[3H]胸腺嘧啶核苷的转运，但它比ACTH更快地降低DNA合成。这种抑制可能是细胞松弛素B破坏微丝的结果，因为我们的证据表明它不是由细胞葡萄糖摄取减少引起的。
