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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The response of peripheral tissues to insulin is reduced in fasting and diabetes mellitus. The experiments described herein were designed to determine whether insulin-stimulated glucose oxidation is affected by the free-fatty acid-derived plasma metabolites acetone, acetol, and propylene glycol (1,2-propanediol [1,2-PD]), concentrations of which are elevated in both starvation and diabetic ketosis. In epididymal adipose tissue from fed and 48-h--fasted rats given 3% acetone drinking water for 7 days, insulin-stimulated glucose oxidation was reduced by approximately 30-40%. After ingestion of 2% acetol for 7 days, basal and insulin-stimulated glucose oxidation was lowered approximately 30%, whereas the consumption of 1,2-PD had no influence on either basal or insulin-stimulated glucose oxidation. Similar effects on glucose oxidation were observed in isolated adipocytes from fed rats after ingestion of 3% acetone and 2% acetol for 7 days. The reduction in insulin-stimulated glucose oxidation in adipose tissue in vitro required the consumption of 3% acetone water for greater than 3 days. In 48-h--fasted rats that ingested 3% acetone for 5 days, insulin-stimulated glucose oxidation remained depressed 4 days after withdrawal of acetone from the drinking water. These studies imply that at least part of the insulin resistance indigenous to fasting and diabetic ketosis may be attributed to the metabolic influence of acetone and/or acetol in body fluids.(ABSTRACT TRUNCATED AT 250 WORDS)
Diabetes 1990 Apr
PMID:Acetone and acetol inhibition of insulin-stimulated glucose oxidation in adipose tissue and isolated adipocytes. 218 Jul 56

Metabolic potency of des-(B26-B30)-insulin-B25-amide, [TyrB25]des- (B26-B30)-insulin-B25-amide and [HisB25]des-(B26-B30)-insulin-B25-amide was studied in anaesthetized rats. Compared to insulin, full potency for des-(B26-B30)-insulin-B25-amide and an enhanced potency for both substituted analogues has been described previously on rat adipocytes in vitro. Hypoglycaemic effects following i.v. injection of all of these analogues were almost identical to those of native insulin with a half-maximal effective dose of approximately 3 nmol.kg-1. Stimulation of glucose metabolism during euglycaemic hyperinsulin-/analogueaemic clamp studies was indistinguishable from that of the native hormone with a maximal stimulation of approximately 19 mg.kg-1.min-1 and half-maximal effective hormone concentrations of approximately 1 pmol.ml-1. Analogue action on individual peripheral tissues estimated by the uptake of 2-deoxyglucose as well as stimulation of lipogenesis in epididymal fat was not different to that of insulin. These data demonstrate that C-terminal amidation of des-(B26-B30)-insulin results in a shortened molecule with full in vivo metabolic potency. When substituting phenylalanine in position B25 by tyrosine or histidine, the insulin-identical potency is preserved.
Diabetes Res Clin Pract 1990 Jul
PMID:In vivo metabolic activity of des-(B26-B30)-insulin-B25-amide and related analogues in the rat. 222 26

Young male obese (cp/cp) and lean (cp/+ or +/+) littermates of the SHR/N-corpulent (cp) strain were fed purified diets containing 54% carbohydrate as either sucrose or cooked starch for 12 wk. A significant effect of phenotype (obese greater than lean) was observed on body weight, epididymal fat pad weight and fat cell size. A diet effect (sucrose greater than starch) was observed on body weight, fat pad weight, and fat cell size. No effect of phenotype or diet was observed on basal 3-O-methylglucose transport in isolated adipose cells. However, insulin-stimulated glucose uptake was decreased 70-80% in isolated adipose cells from obese SHR/N-cp rats. No effect of diet on insulin-stimulated glucose uptake was observed in obese SHR/N-cp rats. Scatchard analysis of insulin binding data demonstrated no differences in the dissociation constant (KD) for the insulin receptor:insulin complex. However, obese rats exhibited a decreased number of insulin receptors compared to lean SHR/N-cp rats. These data demonstrate that the obese SHR/N-cp rat exhibits insulin-resistant glucose transport. This altered insulin sensitivity may be one factor contributing to the development of noninsulin-dependent diabetes mellitus in these animals.
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PMID:Insulin resistant glucose transport activity in adipose cells from the SHR/N-corpulent rat. 264 47

A forty-two year-old man with left epididymo-testicular malakoplakia was reported. Thirty-two cases of testicular malakoplakia with (5 cases) and without (27 cases) epididymal malakoplakia were reviewed. The mean age was 48. 2 year-old. Two-thirds of the cases suffered from right side involvement. All cases except a few cases received orchiectomy within 2.6 months on average from the onset of the symptoms. Diabetes mellitus, malignant diseases, or chronic renal failure seem to have a causal relation to the development of testicular malakoplakia. Six cases of epididymal malakoplakia were also reviewed.
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PMID:[A case of malakoplakia of the testis and epididymis]. 266 1

1. Adipocytes were isolated from epididymal white fat and interscapular brown fat of male rats, and activities of 5'-nucleotidase, adenosine deaminase and adenosine kinase were measured in cell extracts. 2. 5'-Nucleotidase activity in white adipocytes was increased in streptozotocin-diabetes, decreased in hypothyroidism and increased with age. That activity in brown adipocytes was unchanged in diabetes, decreased in hypothyroidism and increased with age. 5'-Nucleotidase activity was higher in white adipocytes from female rats. 3. Adenosine deaminase activity in white adipocytes was increased in diabetes, decreased in hypothyroidism and increased with age. That activity in brown adipocytes was decreased in diabetes and hypothyroidism. 4. Adenosine kinase activity in both cell types was unchanged in diabetes or hypothyroidism, but increased with age.
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PMID:Enzymes involved in adenosine metabolism in rat white and brown adipocytes. Effects of streptozotocin-diabetes, hypothyroidism, age and sex differences. 282 32

These experiments were carried out to study the effects of acute cold exposure (0-2 degrees C/4 hr) on rectal temperature, blood glucose and plasma free fatty acids (FFA) in alloxan-diabetic rats. Male Wistar rats weighing 170-190 g were used and diabetes was induced by i.v. alloxan injection (40 mg/kg body wt). Cold exposure produced severe hypothermia in diabetic rats. After 4 hr of cold, blood glucose of diabetic rats was reduced from 296 +/- 16 to 86 +/- 12 mg/dl (P less than 0.01), and FFA increased slightly, but was not statistically different (P greater than 0.05) from the initial value. As expected, interscapular brown adipose tissue (IBAT) and retroperitoneal and epididymal white adipose tissues were significantly lower in diabetic than in control rats. Cold exposure reduced total IBAT lipids in control but not in diabetic animals. The results of this experiment suggest that diabetic rats were unable to maintain body temperature in the cold, probably because of a failure to generate an adequate amount of heat by nonshivering thermogenesis in brown adipose tissue.
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PMID:Effects of acute cold exposure on rectal temperature, blood glucose and plasma free fatty acids in alloxan-diabetic rats. 287 21

We measured acetyl-CoA carboxylase mRNA levels in various tissues of the rat under different nutritional and hormonal states using a cDNA probe. We surveyed physiological conditions which are known to alter carboxylase activity, and thus fatty acid synthesis, to determine whether changes in the levels of carboxylase mRNA are involved. The present studies include the effects of fasting and refeeding, diabetes and insulin, and lactation on carboxylase mRNA levels. Northern blot analysis of liver RNA revealed that fasting followed by refeeding animals a fat-free (high carbohydrate) diet dramatically increased the amount of carboxylase mRNA compared to the fasted condition. These changes in the level of mRNA correspond to changes in the activity and amount of acetyl-CoA carboxylase. Acetyl-CoA carboxylase mRNA levels in epididymal fat tissue decreased upon fasting and increased to virtually normal levels after 72 h of refeeding, closely resembling the liver response. The amount of acetyl-CoA carboxylase mRNA decreased markedly in epididymal fat tissue of diabetic rats as compared to nondiabetic animals. However, 6 h after injection of insulin the mRNA level returned to that of the nondiabetic animals. Gestation and lactation also affected the levels of carboxylase mRNA in both liver and mammary gland. Maximum induction in both tissues occurred 5 days postpartum. These studies suggest that these diverse physiological conditions affect fatty acid synthesis in part by altering acetyl-CoA carboxylase gene expression.
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PMID:Physiological regulation of acetyl-CoA carboxylase gene expression: effects of diet, diabetes, and lactation on acetyl-CoA carboxylase mRNA. 290 42

1. Previous work has shown that the diabetogenic action of streptozotocin is reduced in rats adapted to a high-protein, carbohydrate-free diet and that plasma valine, leucine and isoleucine concentrations are markedly elevated in rats adapted to the high-protein diet. 2. To test the possibility that these branched-chain amino acids play a role in the beneficial effects of the high-protein diet, rats fed the control balanced diet were injected intraperitoneally with mixtures of valine, leucine and isoleucine (0.25 or 0.50 g/kg body weight of each amino acid), or with each of these amino acids separately (0.50 g/kg), 15 min before streptozotocin administration (40 mg/kg, intravenously). Arginine (0.50 g/kg) was administered in one experiment. Control animals received equal volumes of saline. 3. Rats previously injected with the amino acid mixtures showed a partial but significant reduction of diabetes severity as indicated by lower plasma glucose levels, higher rates of body weight gain and greater amounts of epididymal and retroperitoneal fat. No protection was observed after the administration of either valine, isoleucine, leucine or arginine. 4. These data suggest that the elevated levels of plasma branched-chain amino acids may account at least in part for the initial protective effect of high-protein diets against streptozotocin beta-cytotoxicity when the cells are first exposed to the drug.
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PMID:Administration of branched-chain amino acids reduces the diabetogenic effect of streptozotocin in rats. 296 88

In an attempt to determine the mechanism of insulin resistance in the presence of obesity, we examined effects of insulin on insulin-sensitive phosphodiesterase (PDE) in spontaneously diabetic KK mice. Isolated fat cells prepared from epididymal adipose tissue were incubated, with or without insulin, for 10 min. In the case of subcellular fractionation, only membrane-bound PDE was activated by insulin, as was noted in the case of rat fat cells. The specific activity was decreased in KK mice compared with control C57BL/6 mice. The dose-response curve, expressed as a percent of the maximal insulin effect, shifted to the right and the increase of ED50 indicated a decreased insulin sensitivity in the KK mice. The maximal insulin effect did not change, either when expressed as a percent of the basal enzyme activity or when expressed on a per cell basis. Specific binding of [125I]-insulin in fat cells increased in KK mice and curvilinear Scatchard plots showed an increase of the high-affinity sites. These data indicate that impairment of PDE activation in fat cells of KK mice relates to postreceptor defects and the uncoupling may result in a decreased sensitivity.
Diabetes 1985 Sep
PMID:Insulin resistance of fat cells from spontaneously diabetic KK mice. Analysis of insulin-sensitive phosphodiesterase. 299 83

Uncontrolled diabetes in man is associated with increased plasma and tissue levels of cAMP and decreased cAMP phosphodiesterase (PDE) activity. Spontaneously diabetic BB rats (SDR) were used in these experiments. Specific tissues (i.e. liver and epididymal fat) were studied without therapeutic insulin. Another group of normal animals were rendered diabetic by streptozotocin (STZ) and killed without benefit of insulin therapy. Calmodulin (CM), a small molecular weight protein essential for activation of specific cAMP PDE was assayed. STZ diabetes is associated with a decrease (58%) in CM biological activity and in immunoreactive CM in fat (69%) and liver (13%) tissues. Similarly, SDR rats and the nondiabetic genetic controls (NDR) demonstrate decreased CM bioactivity in fat (76% and 56%, respectively) and decreased CM immunoreactivity in liver (68% and 74%, respectively) compared to normal control rats. In addition, maximum velocity (Vmax) of the low Michaelis-Menten constant (Km) cAMP PDE is decreased in SDR animals, as compared to controls in both fat (42%) and liver (39%) tissues. Similar data are presented for NDR animals. STZ diabetes is also associated with a reduction in Vmax of the low Km cAMP PDE in both liver (70%) and fat (70%) tissues. These changes found in the NDR animals suggests that the diabetic defect may be under dual regulation: genetic and environmental.
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PMID:Spontaneous diabetic BB rat: studies of cyclic adenosine 3',5'-monophosphate phosphodiesterase and calmodulin. 301 47


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