c-peptide and Carcinoma

Inhibition of C-Peptide secretion by exogenous insulin was studied during euglycemic clamp in 13 patients with histologically verified causes of organic hyperinsulinaemia (10 with beta cell adenoma; 2 with beta cell carcinoma and 1 with beta cell hyperplasia) and in 10 healthy controls. Euglycemic clamps were performed using artificial endocrine pancreas (Clamp Mode 9:1) while insulin infusion (Humulin Normal-Lilly) rate was 0.1 U/kg BW/h. Blood samples for serum insulin (RIA INEP) and C-Peptide (RIA-Biodata) were taken at 0; 30; 60; 90 and 120 min. Statistical analysis was done using SPSS on IBM-PC with Wilcoxon sum rank test and one way ANOVA. All the patients were studied before the operation and in four of them clamp studies were repeated after the operation. Statistically significant suppression of C-Peptide values in 120 min was established in the control group (p less than 0.05) while there was no significant suppression in insulinoma group (p greater than 0.05), except in one patient with beta cell hyperplasia. Various types of responses (suppression, no change, paradoxical increase) were observed after the operation in the insulinoma group. Possible mechanisms and the meanings of the absence of insulin induced C-Peptide suppression in insulinoma group are discussed. It is concluded that euglycemic hyperinsulinemic clamp study could be useful and a complementary test to other established tests for the confirmation of the diagnosis of insulinoma. Further work on beta cell response after the operation in patients with insulinoma is necessary.

Topics: Adenoma; Adenoma, Islet Cell; Adult; Aged; Analysis of Variance; Body Mass Index; C-Peptide; Carcinoma; Female; Glucose Clamp Technique; Humans; Hyperinsulinism; Hyperplasia; Insulin; Insulin Secretion; Insulinoma; Male; Middle Aged; Pancreatic Neoplasms

Patients with benign hyperplasia of the prostate and with anaplastic carcinoma have similar activities in their cells in staining for acid phosphatase. After therapy with estrogens the acid phosphatase is significantly inhibited, leucin amino peptidase and succinate dehydrogenase appear to be reactivated in the cells of anaplastic carcinoma. Serum TSH is decreased distinctly, serum levels of LH and prolactin are significantly elevated especially in patients with anaplastic carcinoma of the prostate in comparison to that of patients with treated benign hyperplasia.

Topics: Acid Phosphatase; C-Peptide; Carcinoma; Enzymes; Estrogens; Fibrinolysin; Follicle Stimulating Hormone; Hormones; Humans; Leucyl Aminopeptidase; Luteinizing Hormone; Male; Prolactin; Prostatic Hyperplasia; Prostatic Neoplasms; Succinate Dehydrogenase; Thyrotropin