Elevated plasma proglucagon-like component with a glucagon-secreting tumor. Effect of streptozotocin.
To determine the character of the glucagon secretion and its modification by streptozotocin, were studied the plasma of a patient with recurrent pancreatic alpha-cell carcinoma. The plasma immunoreactive glucagon level before treatment of 4.80 ng per milliliter. Biogel column separation of the plasma immunoreactive glucagon revealed four components; the predominant component had a molecular weight of 9000 daltons and was designated as proglucagon-like. This fraction constituted 60 to 90 per cent of the total circulating immunoreactive glucagon, and had a biologic activity of 32 percent of that of an immunoequivalent amount of normal (porcine) pancreatic glucagon. After treatment with streptozocin (1.5 g per square meter) the plasma immunoreactive glucagon level decreased to 0.24 ng per milliliter. Treatment was accompanied by a marked reduction in the proglucagon-like component and the appearance of pancreatic glucagon (molecular weight of 3500 daltons) as the major post-therapy fraction. These findings support the use of streptozotocin in the management of unresectable glucagon-secreting tumors.
D007516:Adenoma, Islet Cell / Q000097:blood / Q000188:drug therapy / Q000378:metabolism; D000941:Antigens; D003864:Depression, Chemical; D005934:Glucagon / Q000097:blood / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D008113:Liver Neoplasms; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local / Q000378:metabolism; D010190:Pancreatic Neoplasms / Q000097:blood / Q000188:drug therapy / Q000378:metabolism*; D012636:Secretory Rate / Q000187:drug effects; D013311:Streptozocin / Q000494:pharmacology* / Q000627:therapeutic use
D000941:Antigens; D013311:Streptozocin; D005934:Glucagon