Publication: Two-step stimulation of intestinal Ca<sup>2+</sup>absorption during lactation by long-term prolactin exposure and suckling-induced prolactin surge
Issued Date
2009-09-01
Resource Type
ISSN
15221555
01931849
01931849
Other identifier(s)
2-s2.0-69049119371
Rights
Mahidol University
Rights Holder(s)
SCOPUS
Bibliographic Citation
American Journal of Physiology - Endocrinology and Metabolism. Vol.297, No.3 (2009)
Suggested Citation
Narattaphol Charoenphandhu, La Iad Nakkrasae, Kamonshanok Kraidith, Jarinthorn Teerapornpuntakit, Kanogwun Thongchote, Narongrit Thongon, Nateetip Krishnamra Two-step stimulation of intestinal Ca<sup>2+</sup>absorption during lactation by long-term prolactin exposure and suckling-induced prolactin surge. American Journal of Physiology - Endocrinology and Metabolism. Vol.297, No.3 (2009). doi:10.1152/ajpendo.00347.2009 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/27147
Research Projects
Organizational Units
Authors
Journal Issue
Thesis
Title
Two-step stimulation of intestinal Ca<sup>2+</sup>absorption during lactation by long-term prolactin exposure and suckling-induced prolactin surge
Other Contributor(s)
Abstract
During pregnancy and lactation, the enhanced intestinal Ca2+absorption serves to provide Ca2+for fetal development and lactogenesis; however, the responsible hormone and its mechanisms remain elusive. We elucidated herein that prolactin (PRL) markedly stimulated the transcellular and paracellular Ca2+transport in the duodenum of pregnant and lactating rats as well as in Caco-2 monolayer in a two-step manner. Specifically, a long-term exposure to PRL in pregnancy and lactation induced an adaptation in duodenal cells at genomic levels by upregulating the expression of genes related to transcellular transport, e.g., TRPV5/6 and calbindin-D9k, and the paracellular transport, e.g., claudin-3, thereby raising Ca2+absorption rate to a new "baseline" (Step 1). During suckling, PRL surge further increased Ca2+absorption to a higher level (Step 2) in a nongenomic manner to match Ca2+loss in milk. PRL-enhanced apical Ca2+uptake was responsible for the increased transcellular transport, whereas PRL-enhanced paracellular transport required claudin-15, which regulated epithelial cation selectivity and paracellular Ca2+movement. Such nongenomic PRL actions were mediated by phosphoinositide 3-kinase, protein kinase C, and RhoA-associated coiled-coil-forming kinase pathways. In conclusion, two-step stimulation of intestinal Ca2+absorption resulted from long-term PRL exposure, which upregulated Ca2+transporter genes to elevate the transport baseline, and the suckling-induced transient PRL surge, which further increased Ca2+transport to the maximal capacity. The present findings also suggested that Ca2+supplementation at 15-30 min prior to breastfeeding may best benefit the lactating mother, since more Ca2+could be absorbed as a result of the suckling-induced PRL surge. Copyright © 2009 the American Physiological Society.