Estrogen plays an important role in intestinal calcium transport (816.5)

Abstract

Objective: To determine the presence of estrogen receptor β (ERβ) in the small and large intestines between ovariectomized and sham‐operated rats via immunocytochemistry; and to investigate the role of estrogen in calcium uptake in the duodenum. Methods: Twelve 12‐week old female Sprague‐Dawley rats were either ovariectomized (Ovx; n=6) or sham‐operated (Sham; n=6) and sacrificed three weeks later. Segments of the small intestine (duodenum, jejunum, and ileum) and large intestine (cecum) were removed for immunocytochemistry analysis. Duodenal cells were harvested for measurement of calcium transport. Results: Both Ovx and Sham groups were found to have ERβ immunoreactivity in all segments of the intestine although the extent was greater in the Sham group when compared to the Ovx group. The presence of ERβ was more pronounced in the duodenum than the jejunum, ileum, or cecum. The rates of calcium uptake in the Sham group were significantly (P = 0.028) greater compared to the Ovx group. Conclusion: The findings of the present study suggest that estrogen is essential for the regulation of duodenal calcium absorption and that menopause is associated with a decline in calcium absorption which may play a role in postmenopausal bone loss.Grant Funding Source: Supported by Jumonji University and Collage of Human Sciences, Florida State University