催乳素对小鼠乳腺外植体中乳糖合成酶、α-乳白蛋白和半乳糖基转移酶活性的时间效应。

Temporal effect of prolactin on the activities of lactose synthetase, alpha-lactalbumin, and galactosyl transferase in mouse mammary gland explants.

作者信息

Jagoda C A, Rillema J A

机构信息

Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan 48201.

出版信息

Proc Soc Exp Biol Med. 1991 Sep;197(4):431-4. doi: 10.3181/00379727-197-43278.

DOI:10.3181/00379727-197-43278

PMID:1908098

Abstract

The onset of the prolactin (PRL) stimulation of lactose synthesis is between 4 and 8 hr after adding PRL to cultured mouse mammary tissues. The synthesis of lactose is catalyzed by the enzyme lactose synthetase, which is composed of two parts, alpha-lactalbumin and galactosyl transferase. In time-sequence studies, it was found that the activity of galactosyl transferase is enhanced by PRL in concert with the onset of the PRL stimulation of lactose synthesis. In contrast, the earliest detectable effect of PRL on alpha-lactalbumin activity occurred 24 hr after adding PRL to the cultures. It is, therefore, apparent that the rate-limiting component for the PRL stimulation of lactose synthesis in cultured mouse mammary tissues is galactosyl transferase activity.

摘要

向培养的小鼠乳腺组织中添加催乳素（PRL）后，PRL刺激乳糖合成的起始时间在4至8小时之间。乳糖的合成由乳糖合成酶催化，该酶由两部分组成，即α-乳白蛋白和半乳糖基转移酶。在时间序列研究中发现，随着PRL刺激乳糖合成的开始，PRL会协同增强半乳糖基转移酶的活性。相比之下，PRL对α-乳白蛋白活性最早可检测到的影响发生在向培养物中添加PRL 24小时后。因此，很明显，在培养的小鼠乳腺组织中，PRL刺激乳糖合成的限速成分是半乳糖基转移酶的活性。