The effect of acute hypercalcemia on prolactin release in man

The serum prolactin response to acute hypercalcemia during calcium infusion was studied in 7 normal subjects. Prolactin, and calcium levels were determined at 30 minute intervals during the 210 minutes of the infusion. The infusion performed consisted of either normal saline at 3 ml/min for 210 minutes, or 15 mg calcium/kg at 3 ml/min for 180 minutes followed by normal saline infusion for the final 30 minutes. Calcium concentration increased from a base line of 10.0 +/- 0.26 (mean +/- SEM) to a maximal level of 13.6 +/- 0.26 (mean +/- SEM) mg/100 ml, in response to calcium level in response to normal saline infusion. Prolactin level decreased significantly (P less than 0.05) from 9.5 +/- 1.45 (mean +/- SEM) to 3.7 +/- 0.2 (mean +/- SEM) ng/ml at 180 minutes.