Plasma insulin in reactive hypoglycemia

Among 663 standard four-hour oral glucose tolerance tests (OGTT) performed in a Department of Internal Medicine, forty-seven curves demonstrated reactive hypoglycemia of 45 mg. per 100 ml. or less at one or more occasions. Subsequent analysis of the records of the corresponding patients allows their partition into the following groups: IA. Obesity (11), IB. Obesity with chemical diabetes (9), II. Postgastrectomy syndrome (3), III. Chemical diabetes without obesity (1), IV. Renal glycosuria (7), V. Isolated reactive hypoglycemia (16).

In order to determine the role of plasma insulin in the pathogenesis of the syndrome, the insulin response of each group of subjects presenting reactive hypoglycemia was compared to that of a control group of similar age, sex and weight with similar pathological findings but without reactive hypoglycemia. The results indicate that plasma insulin values can not account for the reactive hypoglycemia in the groups IA, IB, III and IV, and thus other factors may be responsible for the occurrence of hypoglycemia in most cases of this syndrome.

In contrast, an exaggerated insulin response exists in group II, and in seven out of the sixteen cases of isolated reactive hypoglycemia.

No correlation was found between the presence of clinical symptoms evoking reactive hypoglycemia during the usual life and the severity of the hypoglycemia recorded during the OGTT.

Biological properties of a transplantable islet-cell tumor of the golden hamster. 3. Electron microscopic studies

This paper describes the ultrastructure of a transplantable islet cell tumor of the hamster. No ultrastructural similarities with normal A or B pancreatic cells were noted. Signs of active metabolism and protein synthesis are the outstanding features of this tumor. The absence of typical β granules and the presence of some peculiar structures are discussed in the light of the demonstrated insulin-producing property of the tumor.

Biological properties of a transplantable islet-cell tumor of the golden hamster. II. Insulin content of the tumor and some metabolic characteristics of the tumor-bearing animals

Hamsters bearing a transplantable pancreatic tumor developed marked hypoglycemia upon fasting. Glucose assimilation constant and fasting plasma insulin levels were statistically higher in these animals than in the controls. The insulin content of the tumor (expressed in “humaninsulin equivalent” was 0.072 ± 0.014 U./gm. wet weight. Insulin could be extracted with acid-alcohol and inactivated with anti-insulin serum or cysteine. The possible significance of these findings is discussed.