期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1980
卷号：77
期号：4
页码：2093-2097
DOI：10.1073/pnas.77.4.2093
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：In organ cultures of mammary glands from mice in midpregnancy, addition of both insulin and prolactin induces a marked accumulation of alpha-lactalbumin, whereas the augmentation of casein synthesis requires the presence of insulin, prolactin, and cortisol. Addition of 0.5 mM dibutyryl cyclic AMP resulted in complete inhibition of alpha-lactalbumin accumulation and partial inhibition of casein synthesis. Furthermore, either cholera toxin at 0.1-1.0 microgram/ml (a stimulator of adenylate cyclase) or 3-isobutyl-1-methylxanthine (an inhibitor of phosphodiesterase) in combination with 2 mM cyclic AMP, produced a similar pattern of inhibition of alpha-lactalbumin and casein synthesis in cultured tissue. During culture of mammary explants in medium containing no hormone, or insulin alone, or insulin, prolactin, and cortisol, the tissue content of cyclic AMP decreased rapidly, reaching half the initial level in 24-48 hr. These results indicate that cyclic AMP plays "negative" regulatory function in hormonal induction of milk protein synthesis during the development of the mammary gland.
