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

The effects of diabetes on the vitamin A metabolism were studied. The concentrations of plasma retinol and retinyl ester were measured in diabetic patients using high-performance liquid chromatography (HPLC). In diabetic patients, the mean level of retinyl ester was significantly elevated compared to that of normal subjects (diabetes, 68.3 +/- 42.5 IU/100 ml of plasma; study I, 87.6 +/- 64.3 IU/100 ml of plasma; study II vs. normal, 29.8 +/- 10.3 IU/100 ml of plasma). The ultracentrifugal and column chromatographic studies were carried out to examine the distribution of retinyl ester in patient's plasma. Ultracentrifugation study showed that the mean of 72.6% of retinyl ester was recovered in the lipoproteins of density higher than 1.006 and the remainder was recovered in the chylomicron (d less than 1.006). Gel filtration profiles for the separation of plasma vitamin A demonstrated that retinyl ester presented in the HDL, LDL and larger molecular size lipoprotein (suspected to be VLDL) as well as in the chylomicron.
 ...
PMID:Vitamin A transport in plasma of diabetic patients. 375 Mar 18

The canine gastric mucosa has previously been shown to contain considerable amounts of a polypeptide with the immunologic and physicochemical characteristics and biologic activity of glucagon (IRG3500). Using mucosal pieces that remained viable for at least 8 h, we have demonstrated that IRG3500 is synthesized in this extrapancreatic tissue. Gel filtration and electrophoresis of extracts of mucosal pieces incubated with 3H-tryptophan, 3H-leucine, or 35S-methionine revealed small amounts of labeled, newly synthesized gastric IRG3500. No labeling of gastric IRG3500 was observed when the mucosa was incubated with 3H-proline, an amino acid not found in glucagon, in the presence of cycloheximide, or in isolated rat hepatocytes. Small amounts of newly synthesized IRG3500 were specifically immunoprecipitated by C-terminally directed glucagon antiserum gamma globulins. The rate of gastric IRG3500 biosynthesis in vitro was apparently unchanged in mucosal pieces from pancreatectomized dogs and unaffected by increased glucose or glucose lack during incubations. Thus we have provided evidence that a hormone of the endocrine pancreas can be synthesized in extrapancreatic tissues.
Diabetes 1985 Jan
PMID:Biosynthesis of glucagon (IRG3500) in canine gastric mucosa. 388 May 48

Assessment of diabetic glycaemic control by nonenzymatically glycosylated albumin (G-A) was investigated. Serum albumin was purified by affinity chromatography on Affi-Gel Blue. Using the purified serum albumin in normal and diabetic subjects, G-A was estimated by a colorimetric thiobarbituric acid (TBA) method and the results compared with the levels determined using aminophenyl boronic acid (PBA) affinity chromatography. There was an excellent correlation between the levels estimated by TBA method and PBA affinity chromatography method (r = 0.94). The levels of G-A increased in patients with poorly controlled diabetes mellitus compared to normals. There was a significant correlation (r = 0.84) between the G-A and HbA1 levels in 43 normal and 167 diabetic subjects. As an estimate of diabetic glycaemic control by G-A, the correlations between the G-A and mean fasting blood sugar (FBS) levels were studied. There was a higher correlation (r = 0.67) between G-A and the mean FBS within 2 weeks. On starting insulin therapy in 8 juvenile diabetic subjects, there was a different temporal relationship between the FBS, G-A and HbA1 levels. The G-A levels were significantly decreased at 1, 2, 3 and 4 weeks compared to the HbA1 levels. The present results indicate that the G-A may provide a valuable tool for assessing the mean blood sugar levels between shorter intervals, since the turnover of serum albumin is considerably faster than that of HbA1.
 ...
PMID:[Determination of glycosylated albumin and its clinical significance in diabetes mellitus]. 405 21

A pancreatic somatostatinoma metastatized to the liver was detected in a 70-yr-old woman presenting with chronic diarrhea, steatorrhea, pancreatic insufficiency, diabetes mellitus, and achlorhydria. At immunocytochemistry, most tumor cells stored both somatostatin and calcitoninlike substances. Chromatography of acid extracts of the tumor on G50 Sephadex gave two distinct peaks coeluting with cyclic ovine somatostatin and human calcitonin, respectively, thus ruling out the hypothesis of a single cross-reacting molecule synthetized by the neoplastic cells. When the tumor was extracted at neutral pH, larger molecular forms of the above components were found, which accounted for less than 20% of the total immunoreactivity. Gel permeation of plasma showed that the circulating calcitonin- and somatostatinlike components consisted of three and four different forms, respectively, including components of molecular weights similar to those of the reference peptides. Inhibition curves and immunoadsorption experiments indicated that the large forms were immunologically similar, if not identical, to the corresponding standard preparations. The present case illustrates the occasional ability of neoplastic somatostatin cells of pancreas to synthetize simultaneously components immunologically related to somatostatin and calcitonin. These two inappropriate secretions could account for the symptoms displayed by this patient.
 ...
PMID:Calcitonin-producing pancreatic somatostatinoma. 610 50

To characterize the glucagon released in response to epineephrine in depancreatized dogs, plasma samples before and during epinephrine infusion were subjected to molecular-sieve chromatography on Bio-Gel P-30 columns. The chromatographic profile for extrapancreatic immunoreactive glucagon (eIRG) revealed two glucagon moieties of molecular weight 9,000 to 12,000. GLI of this molecular weight was released in response to epinephrine only under conditions of prevailing hyperglycemia. To determine if glucagon's participation in epinephrine-induced hepatic glucose overproduction in diabetes was dependent upon the degree of metabolic control, six conscious depancreatized dogs were infused with epinephrine or epinphrine plus somatostatin, under conditions of prevailing hyperglycemia or normoglycemia. Under normoglycemic conditions, epinephrine stimulated eIRG release, but there was a similar rise in hepatic glucose production (Ra) with or without glucagon suppression by somatostatin. Under hyperglycemic conditions, epinephrine stimulated eIRG and GLI release, and the rise in Ra was significantly greater with epinephrine than with epinephrine plus somatostatin infusion. Thus, under conditions of good metabolic control, epinephrine increased hepatic glucose production independently of glucagon, whereas with poor metabolic control, glucagon contributed to hepatic overproduction of glucose.
 ...
PMID:Chromatographic pattern of extrapancreatic glucagon and glucagon-like immunoreactivity before and during stimulation by epinephrine and participation of glucagon in epinephrine-induced hepatic glucose overproduction. 611 73

Gel fractionation of portal, arterial and peripheral plasma glucagon levels was performed before and after the successful removal of a glucagonoma. A 47 year old woman had symptoms of dermatitis, weight loss, anemia and diabetes mellitus over a 16 year period. Removal of the alpha-cell tumor corrected all of her symptoms. Gel filtration of portal, arterial and peripheral blood showed two peaks of glucagon radioimmunoassay activity, a higher molecular weight glucagon with a molecular weight of 9,000 and a 3,500 dalton glucagon. Five minutes after tumor removal, the higher molecular weight glucagon had disappeared completely from the arterial and peripheral blood but not from the portal vein.
 ...
PMID:Pattern of immunoreactive glucagon in portal, arterial and peripheral plasma before and after removal of glucagonoma. 625 27

Acid-ethanol extracts of fetal bovine pancrease were examined for the presence of beta-endorphin-like immunoreactivity. Gel-filtration analyses revealed the presence of a major large-molecular-weight beta-endorphin immunoreactive species of approximately 20K delta. This molecular form maintained its size upon resubmission to gel filtration in the presence of 6 M guanidine hydrochloride, separated from the bulk of the glucagon immunoreactivity upon ion-exchange chromatography, showed proportional dilution in the beta-endorphin radioimmunoassay, and interacted in a biospecific manner with Concanavalin-A-Sepharose.
Diabetes 1984 Mar
PMID:Beta-endorphin-like immunoreactivity in extracts of the fetal bovine pancreas. Column chromatographic characterizations of a high-molecular-weight immunoreactive species. 632 Dec 78

We studied the effects of retinoids on islet cell-to-cell adhesiveness and glucose-induced insulin release from rat islets. For adhesion studies, islets were dispersed using low concentrations of trypsin. Thirteen cis-retinoic acid (13 cis-RA) was added to a suspension of 15 X 10(5) islet cells and adhesion of cells was quantitated using a hemocytometer. For functional studies, we measured biphasic insulin release from collagenase-isolated perifused islets, dispersed cells, and single large aggregates (clumps) of islet cells. Thirteen cis-RA (10(-4) M) stimulated insulin secretion at 9.7, 12.5, 16.7, and 27.7 mM glucose. Maximal effects of 13 cis-RA (174% of control) were evident during second phase release at 9.7 mM glucose. Thirteen cis-RA (10(-7) and 10(-6) M) caused cells to adhere to each other, and at higher concentrations, 13 cis-RA caused dispersed cells to reaggregate into a single clump. These retinoid-induced clumps were perifused in a Bio-Gel P-2 gel column. Secretion from the clump was twofold greater than from an equal number of perifused dispersed cells. Electron microscopic and freeze-fracture examination of the clump showed reaggregated cells to be intact and the presence of gap junctions between cells. In conclusion, 13 cis-RA has marked effects on islet cell-to-cell adhesiveness. Trypsin-dispersed cells reaggregated by 13 cis-RA have anatomical contacts and secrete more insulin as an aggregate than as dispersed cells. Thirteen cis-RA increases insulin release possibly by increasing adhesion or interactions between beta-cells.
Diabetes 1983 Jun
PMID:Cellular mechanisms of insulin release. Effects of retinoids on rat islet cell-to-cell adhesion, reaggregation, and insulin release. 635 84

Highly purified regular porcine insulin was given by portable insulin pumps through indwelling vena caval catheters to 17 (13 normal, and 4 pancreatectomized) dogs initially weighing 15 +/- 2 kg at rates ranging from 2 to 10 mU/min (total 17-250 mg) over time periods ranging from 37 to 252 days. During the course of the study, many of the animals lost weight and became anemic. Since these conditions persisted and weight loss progressed even after cessation of insulin infusion, as many of the dogs as possible (15 of 17) were autopsied for microscopic studies. Large amounts of amyloid were demonstrated in the liver, kidney, spleen, and/or pancreas in 55% (6/11) of normal, and in 75% (3/4) of pancreatectomized dogs. The amyloid deposits were Congo red positive, exhibited classical apple green fluorescence under polarized light, and possessed the characteristic ultrastructural features of amyloid. Massive deposits of amyloid were observed in animals receiving as little as 17 mg of insulin over a time span of 52 days. In those animals with hepatic amyloid, marked hepatomegaly was present (i.e., 1200 +/- 250, X +/- SD, versus 300 +/- 25 g for normal animals) and preterminal serum alkaline phosphatase levels were markedly elevated (434 +/- 285 versus 30 +/- 14 IU/L for animals without hepatic amyloid). The magnitude of the hepatic amyloid deposits precludes the possibility that they represent insulin aggregates or insulin-derived products per se. No evidence of amyloid was present in any of the tissue biopsy specimens obtained prior to insulin infusion. Moreover, the possibility that this represents an immune response to the injected porcine insulin has to be viewed in light of the fact that the amino acid sequences of dog and porcine insulins are identical. It is of particular interest that the affinity of the amyloid deposits for Congo red stain was totally abolished by prior permanganate treatment, suggesting that the amyloid was derived from serum amyloid A protein rather than from immunoglobulin light chains or insulin aggregates per se. Further evidence that the protein was of the AA-type came from the initial biochemical characterization. Gel filtration on Sephadex G100 in 6 M guanidine hydrochloride identified two small molecular weight peaks of about 13,000 and 25,000 daltons, both of which inhibited the radioimmunoassay for human AA protein.(ABSTRACT TRUNCATED AT 400 WORDS)
Diabetes 1983 Dec
PMID:Unanticipated amyloidosis in dogs infused with insulin. 636 Jul 58

Filtered proteins including insulin are absorbed in the proximal tubule by means of pinocytosis. The first step in this process is binding of the protein to brush border membrane. As it is not known whether absorption exhibits specificity, we set out to determine whether specific binding sites for insulin are present in brush border membranes. Rabbit-isolated brush border membranes were incubated with 125I-insulin and varying concentrations of cold insulin or other peptide hormones. Binding and degradation of 125I-insulin occurred in a time- and temperature-dependent manner. Native insulin competitively inhibited 125I-insulin binding, but calcitonin, arginine vasopressin, glucagon, and growth hormone (10(-6) M) were relatively ineffective. Nonspecific binding averaged one-third of the total radioactivity bound. Scatchard analysis of binding data revealed two classes of insulin receptors: high affinity, low capacity receptors and low affinity, high capacity receptors. Gel filtration analysis of 125I-insulin exposed to brush border membrane revealed the formation of low-molecular-weight products similar to that produced by intact kidneys. The degrading process exhibited some specificity, for cold insulin (10(-6) M) was more effective than calcitonin, vasopressin, glucagon, or growth hormone in inhibiting degradation (32% versus less than 13% inhibition; P less than 0.01). Whether this reflects inhibition of insulin specific binding before exposure to degradation or inhibition of specific enzymes is unclear. In summary, it appears that renal brush border membranes have a major insulin-specific receptor component that could potentially mediate tubular insulin absorption. In addition, there is a smaller nonspecific component that may also have the potential to mediate insulin absorption. Finally, it appears that brush border membranes have the ability to degrade insulin to low-molecular-weight products by a process that exhibits some specificity for insulin.
Diabetes 1982 Jul
PMID:Binding and degradation of insulin by isolated renal brush border membranes. 676 Dec


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>