Henry Ford Hospital Medical Journal


The presence of clinically undetectable medullary thyroid cancer can be revealed by characterisdc patterns of calcitonin in serum after the injection of a provocative agent, pentagastrin or calcium ion. However, in some reports, medullary thyroid cancer was uncovered in a test with pentagastrin but not in one with calcium ion, and vice versa. To reduce the number of erroneous responses, each provocative agent has been employed in separate tests. Combining pentagastrin and calcium into one stimulus should give the advantage of each agent while requiring less time and fewer analyses in a single test. We combined pentagastrin injection and calcium ion infusion into a single stimulus of calcitonin secretion. Normal responses to each pharmacologic agent and to the combination were established. In patients with medullary carcinoma, the combined stimuli usually, but not always, elicited a greater rise in serum calcitonin concentration than did the more potent of the two agents alone. However, we encountered no false negative results in any of the methods used: pentagastrin alone, calcium ion alone, or pentagastrin combined with calcium. Still, normal responses to both agents theoredcally give greater assurance that medullary cancer and hereditary disease are absent. The symptoms associated with the provocative tests were the same as, or no worse than, those reported for each agent alone. Serum calcium concentrations increased for a few minutes after calcium gluconate was administered, but, with practice at infusions, maximum concentrations were held below 14.2 mg/dl.