Serum gastrin and motilin in treated and untreated hyperthyroidism.

To study the gastrointestinal hormones in hyperthyroidism and the interrelations with the thyroid hormones, the preprandial serum gastrin and motilin were measured by radioimmunoassay in 104 patients before and after the treatments. The following results were obtained: 1) Serum gastrin concentration in hyperthyroidism was significantly higher than that of the control, and when the patients reached euthyroidism or hypothyroidism after the treatments, the gastrin concentrations in the serum decreased to the normal level. There was a positive correlation between the thyroid hormones and the serum gastrin. 2) Serum motilin concentration in hyperthyroidism was slightly lower than that of the control. As the patients reached the euthyroid or hypothyroid state after the treatments, an increasing tendency of motilin was observed, though the change was not significant. There was a slightly negative correlation in gastrin versus motilin and also in T4 versus motilin.