[Differences found in serum serotonin between a group of normal and subjects of obese patients following intravenous tolbutamide administration].

We have studied the effect of the i.v. administration of 1 g tolbutamide upon glycemia, insulinemia and serotoninemia in normal subjects and obese patients. We have seen an elevation of the last two variables in direct relationship with the previous blood sugar levels. The baseline serotonin level in obese people is higher than in normals, but the tolbutamide induced elevation is of a lesser magnitude. We believe this fact is due to the competitive action of insulin, as our obese patients have shown to have a "hyperinsulinism" with "disinsulinism".