Komura H, Wakimoto H, Chen C F, Terakawa N, Aono T, Tanizawa O, Matsumoto K
Endocrinology. 1986 Apr;118(4):1530-6. doi: 10.1210/endo-118-4-1530.
Addition of epidermal growth factor (EGF) at up to 100 ng/ml to the medium of cultured explants of mouse mammary gland increased thymidine incorporation into DNA dose dependently. Addition of retinoic acid alone at 10 micrograms/ml to the medium had no significant effect on DNA synthesis, but addition of EGF with retinoic acid enhanced the EGF-stimulated DNA synthesis. Furthermore, pretreatment of mammary explants with retinoic acid enhanced the effect of EGF plus retinoic acid on cell growth. EGF inhibited the synthesis of casein and decreased alpha-lactalbumin activity of mammary explants in culture in the presence of insulin, cortisol, and PRL. Retinoic acid alone had no significant effect on the synthesis of casein, but suppressed alpha-lactalbumin activity dose dependently. Concomitant addition of retinoic acid with EGF had no significant effect on EGF-induced inhibition of casein synthesis, but enhanced EGF-induced inhibition of alpha-lactalbumin activity dose dependently. Measurement of specific binding of [125I]EGF to mouse mammary glands in culture demonstrated that pretreatment of the explants with retinoic acid slightly, but significantly, enhanced the specific binding of EGF to its cellular receptors.
向培养的小鼠乳腺外植体培养基中添加高达100 ng/ml的表皮生长因子（EGF）可使胸苷掺入DNA的量呈剂量依赖性增加。单独向培养基中添加10微克/毫升的视黄酸对DNA合成无显著影响，但EGF与视黄酸共添加可增强EGF刺激的DNA合成。此外，用视黄酸预处理乳腺外植体可增强EGF加视黄酸对细胞生长的作用。在胰岛素、皮质醇和催乳素存在的情况下，EGF抑制培养的乳腺外植体中酪蛋白的合成并降低α-乳白蛋白活性。单独的视黄酸对酪蛋白的合成无显著影响，但剂量依赖性地抑制α-乳白蛋白活性。视黄酸与EGF同时添加对EGF诱导的酪蛋白合成抑制无显著影响，但剂量依赖性地增强EGF诱导的α-乳白蛋白活性抑制。对培养的小鼠乳腺中[125I]EGF特异性结合的测量表明，用视黄酸预处理外植体可轻微但显著增强EGF与其细胞受体的特异性结合。
