Abstract
Urinary cyclic AMP excretion was greater in patients with renal hypercalciuria than in those with normocalciuria, indicating an increased secretion of PTH in group 2. This conclusion is not altered by the finding that group 2 patients had higher serum creatinine values than group 1 patients. However, in spite of their higher secretion of PTH, group 2 patients did not show higher serum prolactin values than group 1 patients. Thus the present results do not provide support for the thesis that PTH-mediated enhancement of serum prolactin levels underlies stimulation of renal synthesis of 1,25 (OH)2D3 in patients with renal hypercalciuria.