Role of calcium and beta-adrenergic system in control of parathyroid hormone secretion.

In the rat, EDTA and isoproterenol stimulated PTH secretion, whereas high calcium and propranolol inhibited it. The stimulatory effects of EDTA and isoproterenol were still evident and unaltered in the presence of blocks induced by propranolol and high calcium, respectively. The findings suggest that: (i) both calcium and beta-adrenergic stimuli affect PTH secretion; and (ii) the two influences affect the PTH secretion by separate initial pathways.