January 06, 2020

Interpretive Summary: Regulation of maternal calcium homeostasis in sheep

Interpretive Summary: Serotonin regulates maternal calcium homeostasis during the perinatal period of sheep

By: Anne Wallace

Serotonin is a neurotransmitter produced from the amino acid tryptophan, which is first converted to the intermediary molecule 5-Hydroxytryptophan (5-HTP). In this December 2019 study published in the Journal of Animal Science, researchers supplemented pregnant sheep with serotonin precursors L-Tryptophan and 5-HTP in order to evaluate how calcium homeostasis and gene expression was affected by this neurotransmitter.

Sheep infused with IV saline, saline with L-tryptophan, or saline with 5-HTP for seven days prepartum. Mammary tissue, femur tissue, postpartum milk and serum (pre- and post-partum) was collected and analyzed. The 5-HTP infusions increased total serum calcium and total milk calcium of sheep, compared to the control.  Several transport proteins involved in calcium homeostasis e.g. the parathyroid hormone-related protein (PTHrP) sodium/calcium exchanger, were also found to be up-regulated in sheep infused with 5-HTP and L-Tryptophan.

The results of this study support the researchers’ goal to better understand how serotonin affects calcium homeostasis in pregnant and lactating sheep. More in-depth studies evaluating the effects of serotonin precursors on milk quality and lamb health and development may also be warranted.