A case of dopamine agonists inhibiting pancreatic polypeptide secretion from an islet cell tumor.
A patient with a large prolactinoma developed a metastatic islet cell tumor secreting pancreatic polypeptide. Dopamine agonist drugs reduced the prolactin levels to normal, caused a 7-fold decrease in the pancreatic polypeptide levels, and inhibited the liver metastases. Elevated chromogranin A levels also normalized on the higher doses of bromocriptine. Dopamine receptors are found in many endocrine tissues, and the expression of dopamine-2 receptor on endocrine tumors establishes the potential for response to dopamine agonist treatment. The relatively benign risk profile of dopaminergic agents makes further testing of these drugs to treat neuroendocrine tumors a worthwhile endeavor.
Pathak
Ram D
RD
Department of Internal Medicine, Section on Endocrinology and Metabolic Diseases, Ochsner Clinic Foundation, New Orleans, Louisiana 70121, USA.
Tran
Tuan Huy
TH
Burshell
Alan L
AL
D007516:Adenoma, Islet Cell / Q000175:diagnosis / Q000188:drug therapy* / Q000378:metabolism*; D001971:Bromocriptine / Q000008:administration & dosage / Q000627:therapeutic use*; D053379:Chromogranin A; D002864:Chromogranins / Q000097:blood; D018491:Dopamine Agonists / Q000008:administration & dosage / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000175:diagnosis / Q000556:secondary; D009378:Neoplasms, Multiple Primary / Q000378:metabolism; D010190:Pancreatic Neoplasms / Q000175:diagnosis / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D010191:Pancreatic Polypeptide / Q000037:antagonists & inhibitors*; D015175:Prolactinoma / Q000175:diagnosis / Q000188:drug therapy
D053379:Chromogranin A; D002864:Chromogranins; D018491:Dopamine Agonists; D001971:Bromocriptine; D010191:Pancreatic Polypeptide