Pancreas insulinoma

In diabetes mellitus the plasma level is generally low. In patients with islet cell tumours of the pancreas (insulinoma) plasma levels are high. 

Obesity and hyperglycemia 2. 2-AG levels are elevated in mouse adipocytes and epididymal of mice with DIO. AEA and 2-AG levels are elevated in rat insulinoma p-cells, in pancreas of mice with DIO, and in obese women. Patients with obesity or hyperglycaemia caused by type 2 diabetes exhibit elevated levels of 2-AG or of both endocannabinoids in visceral fat or blood, respectively. AEA levels are elevated in the liver of DIO mice 2. CB1 antagonists... 

Diazoxide inhibits insulin release from the pancreas (probably by opening potassium channels in the beta cell membrane) and is used to treat hypoglycemia secondary to insulinoma. Occasionally, hyperglycemia complicates diazoxide use, particularly in persons with renal insufficiency. 

Doppman JL, Chang R, Fraker DL, Norton JA, Alexander HR, Miller DL, et al. Localization of insulinomas to regions of the pancreas by intra-arterial stimulation with calcium, Ann Intern Med 1995 123 269-73. 

In the case of °Y-DOTATOC, a dog with a suspected insulinoma in the pancreas was injected twice, first with 10 mCi (370 MBq) and then with 5 mCi (185 MBq) of the labelled peptide, within a period of six weeks. Chnical and ultrasound imaging follow-up were provided. However, no base level diagnostic scintigraphy could be obtained prior to treatment, as the Tc-HYNIC-TATE was not yet available for use in the study. Follow-up with Tc-HYNIC-TATE was performed on the animal. 

Pancreatic endocrine neoplasms (PENs) are the majority of the endocrine neoplasms in the pancreas.Most PENs are sporadic. However, these tumors also constitute one of the major components of the multiple endocrine neoplasia I (MENl) syndrome or may arise in patients with vHL syndrome. Those that are associated with increased serum levels of hormones and lead to corresponding symptoms are referred to as functional and are named according to which hormone they secrete (e.g., insulinoma—42% of all functional variants, gastrinoma—24%, glucagonoma—14%,... 

In the pediatric population, pancreatic tumors are very unusual entities. They account for less than 5% of all malignancies in children. These tumors may arise from the exocrine or endocrine pancreas. Exocrine neoplasias include ductal adenocarcinoma, acinar adenocarcinoma, pancreaticoblastoma, or infantile adenocarcinoma. Endocrine tumors or islet cell tumors are named after the hormone produced, with insulinoma being the most common in children (Walker 1996). 

Neoplasias that arise from the endocrine portion of the pancreas can be classified as secretory or non-secretory (Gouya et al. 2003). When secretory, the endocrine tumor will be subclassified according to the type of hormone produced (insulin hormone, gastrin hormone, or active peptides). Insulinomas are the most common endocrine tumors, while glucagonomas or somatostatinomas have not been reported in children. 

A test that can be used for the diagnosis of insulinoma. Tolbutamide is a drug which stimulates insulin release from the pancreas. It is injected intravenously and blood samples are collected for up to three hours. In normal subjects, the blood glucose level falls and then returns to normal. However, in patients with insulinoma, a greater fall can occur and the hypoglycaemia persists for much longer. 

Regarding stimulation of insulin secretion "in vitro" by amino acids, pieces of rat and rabbit pancreas mere incubated in media consisting of the usual buffer plus o.l, l.o and 10 mg amino acid/ml for 2 and 3 hours, respectively (Pfeiffer et al (1967), Yeboah (1967)). In Fig. 7 are shomn the responses of rabbit and rat pancreas "in vitro" to 1-leucine, the first amino acid shomn to induce insulin secretion "in vivo" in insulinoma patients (Cochrane, et al (1956)). Increases in Iffll concentrations up to 300% of the initial values recorded as 100 mere noted. Higher sensitivity of the rabbit than of the rat 0—... 

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