The effect of high level CaCi2 injection on parathyroid hormone dependent cAMP in stone formation patients.

Patients with a history of idiopathic calcium oxalate stones but without current stone formation do not react to stimulation of parathyroid extract as expected after high dose calcium pretreatment. With Ca2+ pretreatment, these patients show higher serum and also renally generated levels of cAMP after rapid injection of extreme parathyroid extract-concentrations. Healthy controls show a modest increase of serum levels cAMP after similar stimulation with parathyroid extracts. In contrast to patients, calcium pretreatment of controls significantly decreases the renal cAMP response to parathyroid extract stimulation. Without Ca2+ pretreatment, both patients and controls show a strong increase in urinary and also in renally generated cAMP levels following parathyroid extract stimulation.