Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: HUMANGGP:034761 (insulin)
 211,843 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Gel filtration of acromegalic or normal serum at acid pH gave two distinct species of non-suppressible insulin-like activity (NSILA), one of high MW and the other of low MW (approximately 7000 daltons). The acid-stable high MW form remained high MW on rechromatography in acid. Gel filtration of serum at neutral pH however, gave only high MW activity, which remained high MW when rechromatographed under neutral conditions but split into both high and low MW forms when rechromatographed in acid. These results indicate that there are at least two circulating forms of NSILA--a low MW form which circulates in serum bound to a carrier protein in an acid-labile high MW complex and a species which circulates only as a stable, discrete high MW protein.
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PMID:The occurrence of a distinct high molecular weight form of serum non-suppressible insulin-like activity. 4 88

Growth hormone release-inhibiting hormone (somatostatin), a hypothalamic peptide that inhibits the release of growth hormone and also the secretion of insulin glucagon, and gastrin, was found in the rat stomach and pancreas in a concentration similar to that in the hypothalamus, as measured by radioimmunoassay. Somatostatin was also found in the duodenum and jejunum, but in a smaller concentration. Gel filtration of the extracts of the pancreas and stomach on Sephadex G-25 yielded two immunoreactive peaks, one corresponding in each case to the somatostatin tetradecapeptide. The hormone was not detected in other viscera or the ovaries. The results imply that somatostatin may be synthesized in the pancreas and the stomach in addition to the brain, and may be involved in local regulatory mechanisms for pancreatic and gastric secretion as well as secretion of growth hormone.
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PMID:Somatostatin: abundance of immunoreactive hormone in rat stomach and pancreas. 5 79

When nine diabetic patients supplemented either their normal home diets (four patients) or metabolic ward diets (five patients) with 25 g guar gum daily for 5 or 7 days their mean urinary glucose excretion fell by 46% (P less than 0-05) and 54% (P less than 0-01), respectively. Gel-forming,, unabsorbable carbohydrate may therefore be a useful adjunct to anti-diabetic therapy, irrespective of the type of treatment or insulin dosage used.
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PMID:Treatment of diabetes with guar gum. Reduction of urinary glucose loss in diabetics. 7 98

Primary cultures of rat liver parenchymal cells maintained as a monolayer in serum-free culture medium were used to investigate the characteristics of zinc accumulation in vitro. Liver parenchymal cells accumulated zinc by a temperature-dependent, saturable process that was inhibited by cyanide, azide, oligomycin, N-ethylmaleimide and iodoacetamide. Cadmium reversibly inhibited zinc accumulation in both serum-free and serum-containing media. Gel filtration chromatographic studies showed that recently accumulated intracellular zinc was present as a low molecular weight complex smaller than metallothionein, the zinc storage protein, but larger than individual amino acids. The quantity of zinc accumulated was affected by preincubation of the cells with various hor?ONES. Dexamethasone, prednisone and prednisolone each increased zinc uptake by 40--50% when either insulin or glucagon was also present. Hydrocortisone, cortisone and sex steroids did not influence zinc accumulation. Removal of the polypeptide hormones from the medium abolished the stimulatory effect of the synthetic glucocorticoid steroid hormones on zinc accumulation.
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PMID:Zinc uptake by isolated rat liver parenchymal cells. 7 27

The degradation of insulin by isolated rat liver cells has been studied. The phenomenon is time- and temperature-dependent. After sixty minutes' exposure to 1.5 times 10-6 cells/ml, about 50 per cent, 15 per cent, and less than 5 per cent of insulin at 1.5 muM. are degraded at 37 degrees C., 20 degrees, and 0 degrees C., respectively. The methods used to measure the hormone degradation effect the apparent Vmax. Higher values of Vmax are found when radioimmunoassay rather than precipitation by trichloracetic acid and absorption to talc is used. However, the apparent Km. (0.27 muM) is virtually the same with any of methods used. N-ethyl-maleimide and Trasylol are potent inhibitors, whereas GSH increases the hormone degradation. Proinsulin acts as competitive inhibitor (apparent Ki equals 0.35 muM.). Gel filtration patterns of incubation supernates suggest that several enzymatic systems may be operative in the degradation of insulin by the liver cells. Glutathione-insulin-transhydrogenase is suggested by the appearance of a component that has the same elution volume as the A chain, but the inhibitory effects of trasylol on insulin degradation, as well as qualitative and quantitative similarities with insulin proteases, suggest that a proteolytic similiarities with insulin proteases, suggest that a proteolytic mechanism is involved. The insulin-degrading system in isolated liver cells closely resembles that observed in purified liver plasma membranes and in the isolated perfused liver. Such similarities stress the possible significance of the degradation process in the regulation of insulin action. These studies are also important for the quantitative analysis of insulin interaction with its specific receptors in isolated liver cells.
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PMID:Degradation of insulin by isolated rat liver cells. 16 96

Immunoreactive glucagon (IRG) fractions from plasma of 8 normal subjects and 4 patients with glucagon secreting tumors were studied by gel filtration techniques on Bio Gel P--30 and Sephadex G--50 columns. The pancreatic glucagon specific anti serum (30K) of Unger was utilized to measure IRG. Columns were calibrated with labelled albumin, proinsulin, insulin and glucagon. Four peaks were defined in normal and tumor bearing patients: peak I (greater than 20 000 mol. wt.), peak II (primarily 9000 mol. wt.), peak III pancreatic glucagon (3500 mol. wt.) and peak IV small gucagon (less than 3500 mol. wt.). Glucagonoma patients differed from our normal and reported normal subjects in that peak II contained most of the circulating IRG. The percent of IRG associated with peak II was 9.5--31.5% in normals and 39.1--61.2% in glucagonomas. Glucagon-like biological activity in an isolated hepatocyte system was demonstrated for all peaks. However, relative to immunoreactivity, peak II showed reduced activity (25--33%). Immunoassay of dilutions of all peaks revealed the probability of immuno determinants identical with procine pancreatic glucagon. The presence of heterogenous IRG peaks with biological glucagon-like activity suggest that the larger molecules may be prohormones. Further, it is possible that specific elevation of peak II may be a diagnostic feature of glucagonomas.
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PMID:Plasma immunoreactive glucagon fractions in four cases of glucagonoma: increased "large glucagon-immunoreactivity". 18 97

Basal immunoreactive glucagon was elevated in four of nine asymptomatic relatives of a patient with glucagonoma. Immunoreactive glucagon remained elevated throughout 22 to 25 hours of continuous observation. Glucagon responses to intravenous glucose and arginine or mixed meals (or both) were abnormal, whereas glucose and insulin responses were normal. Gel filtration of plasma revealed that over 85 per cent of the four relatives' immunoreactive glucagon had a molecular weight of greater than 9000 daltons whereas that of 70 per cent of the patients with glucagonoma had a molecular weight of 3500 daltons, with the remainder eluting in the area of 9000 daltons. Pancreatic angiograms and hepatic scintiscans were normal in all four relatives. The data suggest an autosomal dominant transmission of hyperglucagonemia in this family. Immunoreactive glucagon with a molecular weight of 3500 or 9000 daltons appears to be required for the development of the clinical glucagonoma syndrome.
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PMID:Familial hyperglucagonemia--an autosomal dominant disorder. 18 88

These studies were undertaken to characterize the high molecular weight immunoreactive insulins in plasma and tumor extracts of two patients with insulinoma, and to determine whether they are biosynthetic precursors of proinsulin. Plasma was chromatographed on a Sephadex G-50 column and fractions assayed for IRI. Three peaks were observed, one in the void volume region (6%), a peak in the proinsulin region (25%), and the largest peak comigrating with insulin standard (69%). Insulinoma slices were incubated for 4 h and high molecular weight IRI was observed in chromatographed extracts of the tumor, as well as in extracts of the incubation medium, which comprised up to 3% of the total IRI. Gel filtration chromatography of a pre-operative fasting plasma from the second patient revealed a heterogeneous distribution of IRI, with approximately 53% in the high molecular weight region. At surgery an insulinoma was removed. Slices were incubated for 4 h with 14C-amino acids and extracts chromatogrphed. 14C-labeled protein was observed in the V0, and in the proinsulin and insulin regions. These 14C-labeled proteins were precipitated with anti-insulin serum, and it was determined that whereas 60-90% of 14C-protein in the proinsulin-insulin region was precipitated, virtually none of the 14C-protein in the V0 was immunoprecipitated with anti-insulin serum. The specific activities (CPM precipitated by anti-insulin serum/muU IRI) were 1, 11.4, and 3.1 for V0, proinsulin, and insulin regions, respectively. These results suggest that proinsulin is synthesized first, followed by insulin, and then the high molecular weight IRI. The high molecular weight IRI is not a biosynthetic precursor of proinsulin. Rechromatography of the high-molecular weight IRI in the presence of 8M urea dissociated 90% into smaller immunoreactive components which chromatographed in the proinsulin and insulin region. It was concluded that high molecular weight IRI's are present in plasma, tumor extracts, and incubation medium from insulinoma patients. These high molecular weight IRI's are not biosynthetic precursors, but either aggregates of proinsulin and insulin, or insulin bound to larger proteins. These studies do not rule out the existence in humans of a smaller rapidly-turning over precursor to proinsulin similar to the pre-proinsulin discovered in a rat insulinoma by Chan et al.
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PMID:Characteristics of high molecular weight insulins in insulinoma patients. 19 Feb 61

Fat cells particulate phosphodiesterase activity can be solubilized in high yield (80--100%) in a buffer system (30 mM Tris - HCl, pH 8.0) containing non-ionic detergents (0.1% Brij 30, 1.0% Triton X-100), salt (3.0 mM MgSO4, 5.0 mM NaBr) and dithiothreitol (5.0 mM). Polyacrylamide gel electrophoresis of the solubilized enzyme activity indicated the presence of two bands of activities of different electrophoretic mobilities, both of which hydrolyzed cyclic AMP and cyclic GMP. The solubilized activity eluted from DEAE Bio-Gel columns as a somewhat broad profile with at least two peaks of activity. Activity against both cyclic AMP and cyclic GMP eluted in similar but not identical patterns. The solubilized enzyme and DEAE column eluates wxhibited low (less than 1 micronM) Michaelis constants for cyclic AMP and cyclic GMP. In addition, the increases in phosphodiesterase activity induced by incubation of intact fat cells with insulin or adrenocorticotropic hormone are maintained in the solubilized state.
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PMID:Solubilization and characterization of hormone- responsive phosphodiesterase activity of rat fat cells. 19 14

A case of glucagonoma syndrome with necrolytic migratory erythema, glossitis, anemia, hyperglucagonemia and a malignant, pancreatic A-cell tumour in a 68-year-old male is described. Gel filtration of the highly elevated circulating glucagon immunoreactivity (2200 pg/ml) demonstrated 60% pancreatic glucagon and 30% "proglucagon". Metabolic studies before operation demonstrated suppression of the total plasma glucagon concentration on oral glucose tolerance test, unchanged total plasma glucagon concentration during intravenous glucose tolerance test and insulin-induced hypoglycemia. Administration of arginine was followed by a rise in both the pancreatic glucagon and the "proglucagon", whereas alanine increased only the pancreatic glucagon. The plasma somatostatin level was immeasurable preoperatively. Somatostatin infusion completely suppressed the release of the pancreatic glucagon but did not significantly affect the "proglucagon". After removal of the tumour the skin lesions disappeared and the total plasma glucagon values fell to normal levels (120 pg/ml). Also, other abnormal laboratory findings returned to normal, including the preoperatively observed renal glucosuria.
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PMID:Metabolic studies and glucagon gel filtration pattern before and after surgery in a case of glucagonoma syndrome. 21 26


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