Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Somatostatin, gastrin-releasing peptide (GRP) and gastrin were measured in the stomach of rats with streptozotocin-induced diabetes, insulinoma-bearing rats and their respective controls. Rats injected with streptozotocin exhibited hyperphagia, insulinopenia and severe hyperglycemia. Stomach weights, and the concentrations and total amounts of GRP and gastrin in the stomach, were similar to nondiabetic control rats. The concentration of somatostatin in the stomach of diabetic rats was 25% greater, but the total stomach content of somatostatin was similar to that of control rats. Insulinoma-bearing rats exhibited hyperphagia, hyperinsulinemia and hypoglycemia. Concentrations of GRP and gastrin in the stomach were 72% and 19% lower, respectively, than in control rats. Despite 45% greater stomach weight, the total stomach content of GRP was 61% lower. Stomach concentrations of somatostatin, and total stomach contents of somatostatin and gastrin, were similar in insulinoma-bearing and control rats. The results demonstrate abnormalities in the stomach concentrations of regulatory peptides in rats with diabetes and insulinoma. These abnormalities are not attributable to changes in food intake alone, suggesting specific effects of these metabolic diseases on gastric regulatory peptides and gastric function.
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PMID:Somatostatin, gastrin-releasing peptide and gastrin in the stomach of rats with streptozotocin-induced diabetes and insulinoma. 167 27

Dissociated human insulinoma cells were plated onto plastic multiwell dishes. Cells were maintained for 1 mo on plastic with three passages. Cultures consisted of small colonies with some areas of stratification and few intercellular spaces. Ultrastructural studies indicated that cultured cells had epithelial features with desmosomes at cell-to-cell contacts and intermediate filaments in addition to secretory granules in the cytoplasm. Insulin and C-peptide were released in equimolar amounts in culture media. When challenged for 30 min with 16.7 mM glucose, 1 mM 3-isobutyl-1-methylxanthine, 4 mM tolbutamide, or 10(-6) M glucagon, insulinoma cells responded by a 1.5-, 1.5-, 2-, or 3-fold increase, respectively, in insulin release above baseline levels. A 15-min challenge with 10(-5) M isoproterenol increased insulin secretion by 1.85-fold. By indirect immunofluorescence, an anti-insulin antibody reacted positively with cell cytoplasm, whereas anti-somatostatin and anti-glucagon antibodies did not. Insulinoma cell surface expressed class I MHC molecules but not class II molecules. Immediately after isolation, crude insulinoma cells were contaminated by 2% of DR+ cells from nonislet components that disappeared after several weeks in culture. The ability of insulinoma cells to stimulate allogenic T-lymphocyte proliferation was assessed by [3H]thymidine incorporation in mixed culture combinations. Crude insulinoma cells elicited a strong lymphoproliferative response with a stimulation index ranging between 3.5 and 7, whereas no stimulation was found after 1 mo in culture. It is postulated that absence of class II-positive cells in the stimulatory cell preparation conditioned this immune tolerance across the major histocompatibility barrier.(ABSTRACT TRUNCATED AT 250 WORDS)
Diabetes 1988 Sep
PMID:Structure, function, and immunogenicity of human insulinoma cells. 245 30

Decreased fatty acid and glucose incorporation into human adipose tissue (FIAT and GLIAT) are frequently found in primary hypertriglyceridemia (HTG) and might also contribute to the defective removal of lipoprotein triglyceride (TG) in non-insulin-dependent diabetes mellitus (NIDDM). To study this possible mechanism, FIAT and GLIAT were determined in needle biopsy specimens from 14 patients with newly diagnosed NIDDM and in 14 age- and weight-matched controls. A patient with insulinoma and hyperinsulinism was also studied. FIAT and GLIAT processes were markedly reduced in patients with NIDDM that developed at the onset of maturity. Insulinoma patients, with normal plasma TG, showed FIAT-GLIAT values in the high to normal range before operation. A direct, highly significant correlation (P less than 0.001) was demonstrated between FIAT and GLIAT in diabetics, insulinoma and controls when considered together. Plasma TG and glucose concentrations were inversely related to FIAT and GLIAT. These relationships were independent of the degree of obesity. It is suggested that impaired FIAT and GLIAT might contribute to defective TG removal and HTG which are often demonstrated in NIDDM.
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PMID:Fatty acid and glucose incorporation into human adipose tissue in non-insulin-dependent diabetes and in insulinoma. Inverse relations with plasma triglyceride and glucose concentrations. 628 88

Insulinoma in patients with multiple endocrine neoplasia (MEN) is a rare condition that because of its usual multicentricity presents difficulties not encountered in sporadic patients. In contrast to gastrinoma, which is the most common pancreatic neoplasm associated with MEN I, malignancy and duodenal tumors are much less common for patients with insulinomas, and excellent palliative medication is not available. Accordingly, there is a much greater reliance on surgical therapy for this group of patients. Between 1970 and 1991 a total of 19 patients had surgical treatment of MEN I-related insulinoma. Each patient had hyperinsulinemic hypoglycemia. One patient, with extensive metastases, had unresectable disease. Of the remaining 18, there were 16 (89%) multiple pancreatic tumors. Tumors were located in the neck, body, or tail in 17 cases, 10 of whom also had tumors in the head. Pancreatic resections performed were 1 total, 12 subtotal (7 also had enucleation of tumors from the pancreatic head), and 5 limited distal resections and/or enucleation (conservative resection). There was no operative mortality. One patient developed pancreatitis, fistula, and diabetes following subtotal resection and enucleation. Postoperative cure was achieved in 17 of 18 cases. Recurrent disease occurred in 2 of 5 conservative resections compared to 0 of 12 subtotal resections, with median follow-up times of 10.4 and 10.3 years, respectively. During the follow-up period, four patients died, possibly all due to MEN I-related conditions. Hyperinsulinism in MEN I is associated with the occurrence of multiple, usually benign, pancreatic islet cell tumors, and surgery is an effective treatment modality.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Surgical management of insulinoma associated with multiple endocrine neoplasia type I. 772 33

The ability of chronic endogenous hyperinsulinemia to induce a resistance to insulin action on protein and glucose metabolism was studied in 10 subjects affected by a benign (functioning) insulinoma and 18 healthy subjects by means of infusions of [1-(14)C]leucine and [3-(3)H] glucose. The insulinoma subjects were divided into two groups with moderate (139 +/- 12 pmol/l) (n = 5) and marked (438 +/- 42 pmol/l) (n = 5) hyperinsulinemia and were studied during a euglycemic dextrose infusion. Control subjects were studied postabsorptively and during a low-dose (0.3 mU.kg-1.min-1) (n = 3) and a high-dose (1 mU.kg-1.min-1) (n = 15) euglycemic insulin clamp to match peripheral insulin concentrations with those of insulinoma subjects. In insulinoma subjects there was no correlation among plasma insulin concentration and leucine concentration (r = 0.05), endogenous leucine flux (r = 0.44), hepatic glucose production (r = 0.47), and glucose uptake (r = 0.05). Insulinoma subjects with marked hyperinsulinemia demonstrated a defective suppression of leucine concentrations (100 +/- 11 vs. 65 +/- 5 mumol/l, P < 0.01), endogenous leucine flux (50.1 +/- 6.3 vs. 27.1 +/- 0.9 mumol.m-2.min-1, P < 0.01), and hepatic glucose production (5.4 +/- 2.0 vs. 0.6 +/- 0.6 mumol.kg-1.min-1, P < 0.05), and a defective stimulation of glucose uptake (13.5 +/- 1.6 vs. 41.1 +/- 2.8 mumol.kg-1.min-1, P < 0.001) with respect to normal subjects at a comparable degree of hyperinsulinemia.(ABSTRACT TRUNCATED AT 250 WORDS)
Diabetes 1995 Jul
PMID:Defective insulin action on protein and glucose metabolism during chronic hyperinsulinemia in subjects with benign insulinoma. 778 52

A growing body of evidence suggests that a variety of chronic diseases, including cancer and diabetes, are associated with damage to mitochondrial DNA. Since mitochondria are constantly exposed to high levels of reactive oxygen species, it is likely that oxidative damage to mitochondrial DNA may be responsible for some of these maladies. To determine whether mitochondria can repair this damage, a quantitative Southern blot technique was utilized to identify repair in specific DNA fragments. A 10.8-kilobase mitochondrial restriction fragment was studied employing a probe containing the entire mouse mitochondrial genome. Alloxan was employed to generate oxygen radicals. Insulinoma cells were exposed to alloxan for 1 h, and total cellular DNA was isolated immediately or after intervals of up to 8 h. Alkali treatment was used to identify abasic sites and sugar lesions, endonuclease III was used to identify lesions associated with thymine and cytosine damage, and formamidopyrimidine-DNA glycosylase was employed to recognize formamidopyrimidines and 8-oxoguanines in DNA. The results showed that all forms of damage studied were repaired by 4 h, indicating that mitochondria are able to efficiently repair damage to their DNA caused by reactive oxygen species.
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PMID:Repair of oxidative damage within the mitochondrial DNA of RINr 38 cells. 840 62

Insulinoma in a patient with pre-existing diabetes is exceedingly rare. Only a small number of well-documented cases have been reported in the world during the last 40 years. We describe a case with non-insulin-dependent diabetes mellitus who after seven years of sulfonylurea treatment experienced recurrent episodes of hypoglycemia. Endogenous hyperinsulinism was found and radiographical examination and transhepatic venous sampling confirmed an insulin secreting pancreatic tumor. After surgical excision of the tumor, patient was relieved from hypoglycemic attacks but required to initiate insulin injection for the treatment of hyperglycemia.
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PMID:Insulinoma in a patient with non-insulin-dependent diabetes mellitus. 944 78

Insulinoma in a patient with pre-existing diabetes mellitus is extremely rare. We report a case of an insulinoma in a patient with type 2 diabetes mellitus who after 14 years of sulfonylurea treatment experienced recurrent episodes of hypoglycemia. Endogenous hyperinsulinism was confirmed and endoscopic ultrasonography identified a pancreatic tumor, which was positive for insulin by immuno-histological staining. After surgical excision of the tumor, no further hypoglycemic attacks occurred. Loss of body weight after removal of the tumor correlated with a dramatic reduction of insulin resistance to such a degree that diet alone proved sufficient for satisfactory glycemic control.
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PMID:Insulinoma induced hypoglycemia in a type 2 diabetic patient. 1138 80

Except in diabetic patients receiving insulin or sulfonylureas, hypoglycemia is a rare disorder. It is identified by modified Whipple's criteria consisting of neuroglycopenic symptoms, a blood glucose level equal to or less than 40 mg/dL, and relief of symptoms by glucose use. The sources of the body glucose are dietary intake, glycogenolysis, and [figure: see text] gluconeogenesis. The metabolism of glucose involves oxidation and storage as glycogen or fat. Causes of hypoglycemia include medications or toxins capable of decreasing blood glucose, disorders associated with fasting hypoglycemia, and postprandial hypoglycemic disorders. The most common type of hypoglycemia is insulin-induced hypoglycemia in diabetics. Insulinoma is rare; however, it is the most common hormone-secreting islet cell tumor. The diagnosis is made by the occurrence of hypoglycemia in the presence of symptoms of neuroglycopenia and inappropriately high levels of insulin and C-peptide. In hospitalized patients, the diagnosis is best made by prolonged fast. Most insulinomas are small and require invasive methods for precise localization. In surreptitious insulin use, hypoglycemia is associated with low plasma C-peptide. Postprandial hypoglycemia occurs in response to feeding and is generally caused by excessive insulin effect. It is seen in patients with postgastric surgery and rarely in early diabetes mellitus. Idiopathic postprandial hypoglycemia is rare and seems to be caused by subtle abnormalities of insulin response to food. Treatment of postprandial hypoglycemia consists of frequent small meals, with deletion of refined carbohydrate and increased protein intake. Primary treatment of insulinoma is surgical resection of the tumor.
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PMID:Hypoglycemia. 1143 Jan 83

The general phosphodiesterase (PDE) inhibitor pentoxifylline (PTX), and the PDE type IV inhibitor rolipram (ROL), both increase intracellular cAMP levels and suppress inflammatory cytokine production by T cells and macrophages. We have previously shown that PTX and ROL protect from autoimmune diabetes in nonobese diabetic (NOD) mice. These drugs may mediate some of their anti-inflammatory effects by blocking nitric oxide (NO) production by macrophages. In this study, we investigated the effect of PDE inhibitors in blocking NO production by insulin-secreting NIT-1 insulinoma cells and mouse islet cells in vitro and in vivo. Insulinoma cells and islet cells produced NO when stimulated with a combination of inflammatory cytokines and lipopolysaccharide (LPS). We found that both PTX and ROL markedly suppressed this induced NO production. Islet cells express PDEs III and IV and, accordingly, the PDE III inhibitor cilostamide (CIL) also suppressed NO production, and a combination of ROL and CIL had a synergistic effect. This suppression appeared to be mediated, at least in part, by elevating cAMP level and was mimicked by other cAMP-elevating agents, ie, membrane-permeable cAMP analogs (dibutyryl cAMP and 8-bromo cAMP) and an adenylate cyclase stimulator (forskolin). PDE inhibitors suppressed the expression of inducible nitric oxide synthase (iNOS) mRNA. In vivo treatment with PTX or ROL prevented iNOS protein expression in the islets of NOD mice with cyclophosphamide-accelerated disease. Our findings suggest that PDE inhibitors can protect islets against autoimmunity.
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PMID:Inhibitors of phosphodiesterase isoforms III or IV suppress islet-cell nitric oxide production. 1150 62


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