[Endogenous Serotonin and Milk Production Regulation in the Mammary Gland].

[Endogenous Serotonin and Milk Production Regulation in the Mammary Gland].
Yakugaku Zasshi. 2018;138(6):829-836
Authors: Chiba T, Maeda T, Kudo K
Abstract
　Intrinsic serotonin (5-hydroxytryptamine; 5-HT) synthesized within the mammary epithelium has an important physiological role in milk volume homeostasis in many species including mice, cows, and humans. During lactation, mammary epithelial cells activate 5-HT synthesis by tryptophan hydroxylase 1 (TPH1). TPH1 catalyzes the rate-limiting step in 5-HT biosynthesis within mammary glands. 5-HT synthesized in mammary glands is released into both the apical (milk) and basolateral spaces by a vesicular monoamine transporter. 5-HT released into milk is incorporated by the apical membrane-expressed serotonin reuptake transporter and degraded by the monoamine oxidase A enzyme. Suckling maintains 5-HT at low levels in milk. When the mammary gland becomes filled with milk, 5-HT provides a negative feedback signal that suppresses further milk synthesis in the mammary epithelium. Our research, using human mammary epithelial MCF-12A cells, shows that the expression of β-casein, a differentiation marker, is suppressed via 5-HT-mediated inhibition of signal transducer and activator of transcription 5. Additionally, our results show that reduced β-casein expression in MCF-12A cells is associated with 5-HT7 receptor expression. Furthermore, we show that 5-HT7 receptor-mediated suppression of β...

Source: Yakugaku Zasshi : Journal of the Pharmaceutical Society of Japan - June 7, 2018 Category: Drugs & Pharmacology Authors: Chiba T, Maeda T, Kudo K Tags: Yakugaku Zasshi Source Type: research