[Hypoglycemic and hyperinsulinemic clamp technic to determine the secretory behavior of insulinoma].

In two female patients of 62 and 76 years of age, respectively, who had insulinomas subsequently confirmed by histology, the secretion pattern of insulin-producing tumours was studied. In the 62-year old patient complete reproducible suppression of insulinoma secretion was achieved by means of large exogenous doses of insulin, whereas this was not possible in the 76-year old patient. A modified hypoglycaemic clamping technique was used in the study. It is concluded that, depending on plasma insulin levels, relative suppression of insulinoma is possible, and it is recommended to use the described differentiated clamping procedure to investigate the secretion pattern of autonomous insulin-producing tumours.