Calcium controlled release of PTH and Calcitonin

October 5, 2011 10:26 AM

How does the parathyroid gland actually detect the change in blood calcium levels, triggering the release of PTH? I understand that decreased calcium concentration in the blood/extracellular fluid in the parathyroid stimulates the production and release of Parathryoid Hormone, but what's the mechanism on a molecular/ionic level? Does decreased calcium trigger an action potential of some kind? Does it open a normally calcium-blocked receptor, resulting in PTH release? Bonus points for the same question for the release of Calcitonin from the thryoid gland. Help a fascinated A&P student.
posted by Pantengliopoli to Science & Nature (3 answers total)

Best answer: Here's a free 2004 article from Renal Physiology on the "Role of the calcium-sensing receptor in parathyroid gland physiology."
posted by jedicus at 10:41 AM on October 5, 2011

Best answer: Wikipedia says it's a receptor. "The G-protein coupled calcium receptors (CaR) sense extracellular calcium". Articles like the one jedicus links are probably your best bet for details - there are a lot of questions like this ("we observe that when Ca2+ levels go down, PTH levels go up, and that increases Ca2+ levels. But why?") that are not yet 100% understood and looking in the scientific literature is going to give you a better sense of what's known, what's not known, and more importantly exactly what is the process for figuring something like this out.
posted by Lady Li at 10:44 AM on October 5, 2011

Response by poster: Awesome -- thanks jedicus and Lady Li. Fascinating stuff.
posted by Pantengliopoli at 10:57 AM on October 5, 2011