The effect of hydrocortisone and thyroxine on development of calcium homeostasis in embryonic intestinal epithelium

Abstract

Cytoplasmic Ca2+ concentration of epithelial cells from 14-day embryonic chick duodena decreased during 72 h of organ culture to a value 54% of that found at 17 days in vivo. The ability of cells to maintain a constant Ca2+ concentration when challenged with high extracellular calcium was also significantly reduced. Addition of 1 microM hydrocortisone during culture restored both parameters of Ca2+ homeostasis to that of 16-day uncultured duodena, and rise in cytoplasmic Ca2+ was significant within 4 h of hormone treatment. Thyroxine influenced epithelial Ca2+ similarly, but to a lesser degree and only after 48-72 h of culture. These data indicate that glucocorticoids, and possibly thyroid hormones, influence the development of calcium homeostasis in intestinal epithelium.

Thyroid Hormone and Thyrotropin Regulate Intracellular Free Calcium Concentrations in Human Polymorphonuclear Leukocytes: In Vivo and in vitro Studies

“…Thyroid hormone-induced [Ca"], changes are also well characterized in skeletal muscle, where they upregulate the expression of [Ca++], channels (30), activate the intracellular [Ca"], release channels of the endoplasmic reticulum (31), induce SERCA enzyme gene expression and activity (32)(33), and affect SERCA enzyme mRNA levels (34). In addition, thyroid hormones have been shown to affect [Ca++], in rat pancreatic acini (35) and embryonic intestinal epithelial cells (36), and to act on the Ca" pump expressed on the membrane of human red blood cells (37). This is, however, the first study documenting the ability of thyroid hormones to affect [Ca++], responses in human PMNs.…”