Novel roles of adipocytes in the mammary gland development and breast cancer progression, and involvement of adipokines in the roles

乳腺在出生后的皮下脂肪组织中发育，脂肪细胞作为上皮细胞的哺育细胞。随着脂肪细胞的肥大，非妊娠小鼠乳腺导管发育受损。脂肪细胞的肥大在妊娠早期延缓了导管侧枝的形成，在妊娠中后期延缓了腺泡的形成和成熟。脂肪细胞肥大会导致高瘦素血症，而瘦素在体内和体外都通过脂肪细胞肥大来模拟某些效应。因此，脂肪细胞的肥大抑制了乳腺的发育，瘦素在抑制乳腺发育中起部分作用。

The mammary gland develops in subcutaneous adipose tissue in the post natal period, and adipocytes function as a nursing cell for epithelial cells. With hypertrophy of adipocytes, ductal development of mammary gland in non-pregnant mice was impaired. Hypertrophy of adipocytes also delayed side-branch formation from the duct in the early phase of pregnancy, and acinar formation and its maturation in the mid-and late phase of pregnancy. Hypertrophy of adipocytes caused hyper-leptinemia, and leptin mimicked some effects by hypertrophy of adipocytes both in vivo and in vitro. Therefore, it was suggested that hypertrophy of adipocytes suppressed mammary gland development and leptin partly played a role in the suppression.