Adaptive changes of maternal bone and intestine during lactation

Asst. Prof. Kannikar Wongdee, Ph.D.

Office of Academic Management, Faculty of Allied Health Sciences, Burapha UniversityCenter of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol UniversityE-mail: kannikar@buu.ac.th

OHEC congress at Ambassador City Jomtien, ChonburiSeptember 14, 2012

Bone

Protect internal organs

Site for muscle attachment

Hematopoiesis

Locomotion

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99% of calcium is stored in bone.

Bone mass throughout life

Not only post-menopausal period, pregnancy and lactation also induce massive bone loss.

Bowman and Miller, J Musculoskel Neuron Interact, 2001; Charoenphandhu et al. Trends Endocrinol Metab, 2010

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Maternal calcium metabolism

Maternal calcium loss Fetal transfer during pregnancy (third trimester) Milk production (requires more calcium)

Calcium supply during lactation Bone — bone resorption Diet — intestinal calcium absorption

Charoenphandhu et al., Trends Endocrinol Metab, 2010Charoenphandhu et al. Trends Endocinol Metab, 2010

Adaptive changes of maternal intestine and bone

Technical approach Histomorphometry: bone histomorphometry, micro-CT Cell biology and molecular biology techniques:

PCR, immunohistochemistryPicture:www.albany.edu; www.boripat.ac.th

Maternal villous hypertrophy during lactation

Wongdee K, Teerapornpuntakit J, Siangpro C, Chaipai S, Charoenphandhu N. Duodenal villous hypertrophy and upregulation of claudin-15 protein expression in lactating rats. Journal of Molecular Histology 2012 (in press).

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Wongdee et al., J Mol Histol, 2012

Maternal bone loss during lactation

Suntornsaratoon et al., Am J Physiol Endocrinol Metab, 2010

Human — up to 10% of skeletal mass Lactation-induced osteoporosis (Ofluoglu and Ofluoglu, 2008)

Rodent (6–8 pups) — up to 30% of skeletal mass

Partly under the regulation of PRL

Osteoclast surface Eroded surface

P = pregnancy; L = lactation; PW = postweaning

Picture: www.health.com

Roles of PRL on maternal calcium metabolism

Charoenphandhu N, Wongdee K, Krishnamra N. Is prolactin the cardinal calciotropic maternal hormone? Trends in Endocrinology & Metabolism 2010;21(7):395‒401.

Endochondral bone changes during lactation

Lactation-induced elongation of the long bone.

PRL-induced decreases in total growth plate height.

Suntornsaratoon et al. Histochem Cell Biol, 2010Wongdee et al. J Physiol Sci, 2012

Bone length Growth plate height

Perspective plan

• Fibroblast growth factor 23 (FGF23), bone-derived phosphate-regulating hormone

• Existence of FGF receptors in the intestinal villi.

• FGF23 compromised the 1,25(OH)2D3-induced intestinal calcium absorption.

Khuituan et al. Am J Physiol Endocrinol Metab, 2012

Role of FGF23 in bone and intestine during pregnancy and lactation

Acknowledgements

Assoc. Prof. Narattaphol Charoenphandhu, M.D., Ph.D. MUProf. Nateetip Krishnamra, Ph.D. MUChitchamai Siangpro, B.Sc. BUUSunitra Chaipai, B.Sc. BUUPanan Suntornsaratoon, M.Sc. MUNatchayaporn Thonapan, B.Sc MUJarinthorn Teerapornpuntakit, M.Sc. MU

Research grantsOffice of the Higher Education CommissionFaculty of Allied Health Sciences, Burapha UniversityThailand Research Fund (TRF)NSTDA