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

Acitivites of the hepatic enzymes were determined in spontaneous diabetes rats. The activities of the enzymes were compared with those in normal rats and in streptozotocin diabetic rats. In the spontaneous diabetes rats, glycogen phosphorylase and glycogen synthase were 14.6 +/- 0.6 and 1.73 +/- 0.15 U respectively. The activities of both the enzymes were significantly increased. In the spontaneous diabetes rats glucokinase was 3.82 +/- 0.5 U showing a significant increase. On the contrary, the activity of the enzyme was decreased in the streptozotocin diabetic rats. Glucose-6-phosphatase was increased both in the spontaneous diabetes rats and in the streptozotocin diabetic rats. Fructose-1,6-diphosphatase was increased in the spontaneous diabetes rats. Glucose-6-phosphate dehydrogenase was increased in the spontaneous diabetes rats and decreased in the streptozotocin diabetic rats. In the spontaneous diabetes rats phosphofructokinase showed a reduction of the activity and glucose-6-phosphate dehydrogenase was elevated. These findings are consistent with the results of activities of the hepatic enzymes in adult-onset diabetic patients. These patterns of the hepatic enzymes in the spontaneous diabetes rats were different from those in the streptozotocin diabetic rats. From these patterns of activities of the hepatic enzymes, the spontaneous diabetes rats produced by repetition of selective breeding according to Goto et al. (1975,1976) are an excellent model of human adult-onset diabetes.
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PMID:Activities of hepatic enzymes in spontaneous diabetes rats produced by selective breeding of normal Wistar rats. 15 47

The metabolism and the various metabolic effects of the sugar substitutes fructose, sorbitol and xylitol have been studied and compared to those of glucose. Fructose, sorbitol, and xylitol were found to be metabolized almost completely in the liver, whereas glucose was metabolized only 20-30% by this organ. The sugars and polyols exhibit a number of common effects characteristic of carbohydrate metabolism. Some of them are for example increase in lactate concentration, increase in lactate-pyruvate ratio, decrease in the concentration of free fatty acids, and decrease in phosphate concentration. The only effect that is restricted to fructose, sorbitol, and xylitol, is the stimulation of uric acid biosynthesis. Though sugar substitutes may be regarded as precursors of glucose, they have only little effect on the increase of blood glucose concentration in normal subjects. This may be due to the glucose - fatty acid cycle. It is to be expected that the use of fructose, sorbitol, and xylitol in diabetes mellitus and under stress situations has certain advantages over glucose.
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PMID:[The metabolism of monosaccharides and polyoles]. 81 Apr 29

The purpose of this study was to compare the metabolism and antiketogenic properties of fructose, glyceraldehyde, and sorbitol. Fructose, glyceraldehyde, and sorbitol were readily metabolized and exhibited an antiketogenic effect in both blood and liver when injected intramuscularly to starved (forty-eight hours) rats. Sorbitol had the most pronounced antiketogenic effect and produced an 80 to 90 per cent decrease in the blood ketone bodies sixty minutes after administration. Fructose and glyceraldehyde were equally effective and produced about a 60 to 70 per cent decrease in ketone bodies. Fructose, glyceraldehyde, and sorbitol caused a significant decrease in the concentration of hepatic ketone bodies. In liver, sorbitol was found to be most effective in its antiketogenic action. The concentration of plasma free fatty acids remained unchanged after injection of all three antiketogenic substrates. Fructose, glyceraldehyde, or sorbitol caused increased blood lactate and pyruvate concentrations, and fructose was the most effective of the three substrates. Fructose administration resulted in a significant decrease in hepatic lactate/pyruvate and beta-OH-butyrate/acetoacetate concentration ratios, whereas sorbitol caused an increase in the concentration ratio of these two substrat pairs. Decreases in blood and liver ketone body levels were associated with lowering of liver acetyl-CoA concentration . However, the decrease in hepatic acetyl-CoA produced upon the administration of antiketogenic substrates was not pronounced. Sorbitol administration resulted in the most pronounced increase in hepatic alpha-glycerophosphate concentration. Fructose or glyceraldehyde also caused an increase in alpha-glycerophosphate content. Administration of each of the three antiketogenic substrates produced an increase in hepatic dihydroxyacetone phosphate concentration. All three antiketogenic compounds increased liver glycogen and blood glucose concentrations. No significant changes were observed in hepatic ATP, ADP, or AMP concentrations sixty minutes after the injections of any of the antiketogenic substrates. Although decreased liver acetyl-CoA levels were associated with the antiketogenic effects of the compounds tested, the increased liver alpha-glycerophosphate content best explains the differences between fructose or glyceraldehyde and sorbitol.
Diabetes 1975 Oct
PMID:Antiketogenic action of fructose, glyceraldehyde, and sorbitol in the rat in vivo. 117 62

Fructose 1,6 bisphosphatase activity was measured in rat serum. The activity of the enzyme presented the following characteristics: pH optimum alkaline, between 8-8.5 and inhibited by AMP. The activity was measured in different experimental situations, such as streptozotocin diabetes, hepatocellular injury produced by carbon tetrachloride (CCl4), and bile-duct ligation. In diabetic rat, serum activity increased 2-fold with respect to the control values. In animals treated with CCl4 the activity increased 10-14 fold. On the contrary bile duct ligation decreased activity according to the cholestasis time. The results obtained in this study show that fructose 1,6 bisphosphatase is an enzyme measurable in serum, which changes according to different situations of liver cell injury.
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PMID:Rat serum fructose 1,6 bisphosphatase: modifications in different experimental conditions. 132 53

The polyol pathway is present in tissues of several organs where its activation may participate in the development of diabetic complications. We measured the accumulation of polyol-pathway intermediates in HPT cells isolated from 21 different human kidneys from nondiabetic individuals. When exposed to 27.5 mM glucose in the growth media, cells isolated from approximately 75% of individuals (accumulators) accumulated sorbitol within 1-4 days, whereas 25% (nonaccumulators) accumulated only negligible amounts, even when the period of exposure was extended to 2 wk. Surprisingly, measurement of the activities of the polyol-pathway enzymes showed no difference in the levels of either AR or SDH between accumulators and nonaccumulators, even when the conversion of galactose to galactitol was used to measure AR activity in intact cells independently of SDH. Measurement of sorbitol in the growth media indicated that nonaccumulators were not releasing sorbitol into the growth media. Fructose levels in the conditioned growth media were 4 times higher in the sorbitol-accumulating cells. Together, these results indicate that the tendency of cells from an individual to accumulate significant amounts of sorbitol may reflect the cells' ability to metabolize sorbitol in steps subsequent to the polyol pathway.
Diabetes 1992 Sep
PMID:Variation in sorbitol accumulation and polyol-pathway activity in cultured human proximal tubule cells. 149 57

As the UV-B cataract and early stages of diabetic cataract in rats only touches the epithelium and anterior superficial cortex, a whole lens analysis is not meaningful, but a regional analysis with the freeze-sectioning device has to be performed. Scheimpflug photography with microdensitometric image analysis enables the scientist to discern in vivo single layers along the optical axis of the lens. UV-B cataracts (0.2 J/cm2, every 2nd day) and diabetic cataracts (Streptozotocin (STZ), 70 mg/kg BW) were induced in Brown-Norway rats. The stages of lens opacification were documented by Scheimpflug photography. 8 weeks after start of UV-B treatment and at several dates before onset of visible diabetic cataractous changes, the animals were sacrificed. The lenses were divided reproducibly into 4 or 7 parts such as an equatorial ring and several layers of the central cylinder from anterior to posterior part. The enzyme activity spectrum shows highly region related pattern that would not have been found in a whole lens analysis. Aldose reductase was activated before appearance of visible cataractous changes due to diabetes compared to normal lenses. In contrast Fructose-1,6-biphosphate-aldolase activity was lower before onset of visible changes than in normal lenses, but only within the 1st section where later visible cataractous changes of UV-B cataract could be detected.
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PMID:Regional enzymatic analysis of UV-B and streptozotocin induced diabetic cataract lens. 196 39

Fructose is known to elicit a lower glycemic response than sucrose, and high-fructose desserts have been recommended for a diabetic diet. We compared a cholesterol-free tofu-based frozen dessert (TFD) containing high-fructose corn syrups with a dairy-based sucrose-sweetened ice cream (IC). Six male and six female non-insulin-dependent diabetic patients (mean age 51 yr, mean ideal body weight 143%, fasting blood glucose less than 160 mg/dl) with well-controlled diabetes and managed on oral hypoglycemic agents were studied. Subjects underwent three trials. In the first trial they ingested 50 g glucose, and in the next two trials they ingested 50-g carbohydrate equivalents of either TFD or IC in random sequence. Venous blood was drawn at intervals during the 3-h trials for glucose and insulin determinations. Fasting plasma glucose was not statistically different between IC and TFD trials (130 vs. 121 mg/dl). Peak glucose responses were at 120 min in both trials (190 mg/dl for IC and 222 mg/dl for TFD), with those for TFD being significantly higher (P less than 0.01). Mean glucose area and glycemic index for TFD were significantly greater than for IC (P less than 0.01 and P less than 0.03, respectively). There was no significant difference between mean insulin areas. In summary, the TFD, which contains soybean curd and high-fructose corn syrup, might have been expected to produce more satisfactory postprandial blood glucose levels than IC, which contains sucrose, yet a higher glycemic response was elicited. This is related to the substantial amount of total glucose in this "fructose" dessert.(ABSTRACT TRUNCATED AT 250 WORDS)
Diabetes Care 1990 Apr
PMID:Frozen desserts and glycemic response in well-controlled NIDDM patients. 218 Jun 58

It is now recognized that dietary carbohydrate components influence the prevalence and severity of common degenerative diseases such as dental problems, diabetes, heart disease and obesity. Fructose and sucrose have been evaluated and compared to glucose using glucose tolerance tests, but few such comparisons have been performed for a "natural" sugar source such as honey. In this study, 33 upper trimester chiropractic students volunteered for oral glucose tolerance testing comparing sucrose, fructose and honey during successive weeks. A 75-gm carbohydrate load in 250 ml of water was ingested and blood sugar readings were taken at 0, 30, 60, 90, 120 and 240 minutes. Fructose showed minimal changes in blood sugar levels, consistent with other studies. Sucrose gave higher blood sugar readings than honey at every measurement, producing significantly (p less than .05) greater glucose intolerance. Honey provided the fewest subjective symptoms of discomfort. Given that honey has a gentler effect on blood sugar levels on a per gram basis, and tastes sweeter than sucrose so that fewer grams would be consumed, it would seem prudent to recommend honey over sucrose.
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PMID:Differential effects of honey, sucrose, and fructose on blood sugar levels. 200 97

The effect of dietary fructose on glycemic control in subjects with diabetes mellitus is controversial. Therefore our aim was to conduct a long-term study to examine the effects of dietary fructose on glucose tolerance and insulin sensitivity and to delineate the mechanisms for the effects observed. Six subjects with non-insulin-dependent diabetes mellitus (NIDDM) who were being treated by diet alone consumed 13% of their calories as fructose incorporated into mixed meals in place of sucrose for 3 months as inpatients on a metabolic ward. The following parameters were measured: (1) weekly fasting plasma-glucose concentrations, (2) postprandial serum glucose and insulin levels after four sugar tolerance tests, (3) basal hepatic glucose production, and (4) hepatic and whole-body insulin sensitivity determined during a hyperinsulinemic, euglycemic clamp. When modest amounts of fructose were substituted for sucrose in the diet for 3 months, basal hepatic glucose output remained unchanged (12.84 +/- 1.83 nmol/kg/min v 12.51 +/- 2.00 nmol/kg/min) as did hepatic insulin sensitivity (92% +/- 4% v 93% +/- 4% suppression) and peripheral glucose disposal (22.52 +/- 4.56 nmol/kg/min v 25.80 +/- 9.45 nmol/kg/min) to a 860 pmol/m2/min insulin infusion at euglycemia (4.8 mmol/L). Fructose feeding also did not alter fasting plasma-glucose concentrations or postprandial plasma glucose and insulin responses to oral glucose or fructose loads or to mixed meals containing either sucrose or fructose. In conclusion, substitution of physiologic amounts of sucrose by fructose for prolonged periods is unlikely to have adverse effects on glucose metabolism in diabetic subjects who are being treated with diet alone.
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PMID:Long-term effects of dietary fructose on carbohydrate metabolism in non-insulin-dependent diabetes mellitus. 240 21

Exocrine pancreatic enzyme activities and mineral concentrations were measured in a newly developed congenic strain of corpulent rat (SHR/N-cp). Approximately 4- to 5-wk-old corpulent (cp/cp) and lean (+/?) male rats consumed a diet containing 54% carbohydrate as either cooked cornstarch or 27% cooked cornstarch and 27% fructose for 9.5 mo. After consuming the diet for 3 mo, corpulent rats were hyperinsulinemic, hyperlipidemic and exhibited glycosuria. After consuming the diet for 9.5 mo corpulent rats were twofold heavier and pancreatic weight was 77% that of their lean littermates. Corpulent rats that consumed starch exhibited lower total pancreatic protein with no significant change in total DNA and RNA. In the corpulent rat, both lipase- and chymotrypsinogen-specific activities and both the specific activities and the content of amylase or trypsinogen were lower than those of lean littermates. Fructose consumption resulted in lower pancreatic copper and iron concentrations, and zinc concentration was elevated in corpulent rats. This study suggests that the SHR/N-corpulent rat may be a useful model for studying exocrine pancreatic function in insulin-independent diabetes.
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PMID:Exocrine pancreatic enzyme activities and mineral concentrations in SHR/N-corpulent (cp) male rats. 245 79


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