Burn injury dramatically alters calcium metabolism leading to hypocalcaemia, hypoparathyroidism and hypercalciuria. These consequences make calcium less available to compensate for burn associated bone loss induced by endogenous glucocorticoids and inflammatory cytokines. We previously reported up-regulation of the parathyroid calcium sensing receptor (CaR) in sheep, a finding which could explain the above changes via reduction of the set point for calcium suppression of parathyroid hormone (PTH) secretion. Subsequently, we reported that CaR distributions in cardiac and arterial endothelium were unchanged following burns.
The aim of our present study is to determine the acute effect of burn injury on sheep intestinal CaR following findings that burned children continue to experience hypocalcemia despite an oral calcium intake of nearly 3 g/m2/ day. We therefore want to assess CaR regulation in affected tissues following burns, with the hypothesis that there would be a change in intestinal CaR content, possibly an increase, thereby maintaining high interstitial calcium levels and reducing cell damage.