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)

Diabetes mellitus is associated with a generalized defect in connective tissue metabolism, including decreased growth, poor wound healing, and osteopenia. To determine the role of circulating factors in the etiology of these defects, we studied the effects of diabetic rat serum (DRS) on collagen, the major protein component of connective tissues. After preincubation of costal cartilage from hypophysectomized rats with experimental serum for 20 hours, [3H] proline was added for final four hours of incubation. Collagen and noncollagen protein were quantitated using purified bacterial collagenase. Compared to incubation of tissue in buffer without added serum, collagen production in cartilage incubated with 2% DRS was decreased by 23% (P less than .05), and with 4% serum by 88% (P less than .01). In contrast, serum from normal rats (NRS) increased collagen to 158% above buffer-incubated cartilage at 1.0% (P less than .02) and to 196% at 2% serum (P less than .01). Noncollagen protein production decreased below buffer only after addition of 2% or more DRS and increased above buffer after addition of 2% or more of NRS (178%, P less than .05). Addition of insulin at 10 and 100 mU/mL to DRS did not reverse defective collagen production, and addition of glucose (up to 900 mg/dL) or ketones (20 mmol/L) to NRS did not induce the changes in collagen production seen after addition of diabetic serum. Chromatographic separation of serum revealed that the inhibitory activity of DRS was in the high molecular weight fraction (less than 5000).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Direct inhibition of collagen production in vitro by diabetic rat serum. 328 35

Collagen content (mg/dl of dry weight) was measured biochemically in the extensor digitorum longus and the soleus muscle in rats. Comparison of muscles from diabetic (induced by intraperitoneal streptozotocin injection /60 mg/kg body weight/) and non diabetic controls showed an increase in the collagen content of the extensor digitorum longus, and little change in the soleus. The differences did not attain statistical significance indicating that the accelerated collagen ageing attributed to diabetes may not necessarily be true in all tissues.
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PMID:Muscle collagen content in diabetic rats. 338 56

Following five weeks of alloxan-induced diabetes, female rats were killed and the urinary bladder was used either for organ bath experiments, collagen determination or electron microscopy. Mean bladder weight increased from 70 +/- 3 (SE, n = 8) for controls to 131 +/- 7 mg. (n = 9) for the diabetic rats. Collagen concentration decreased from 104 +/- 5 (n = 8) to 69 +/- 4 (n = 9) micrograms/mg. but due to the weight gain total bladder collagen increased from 7.4 +/- 0.6 to 8.9 +/- 0.3 mg. Electron microscopy indicated an increase in mean cross-sectional area of the detrusor smooth muscle cells from 8.1 +/- 0.5 (n = 132) to 19 +/- 0.9 (n = 144) mu 2. Despite these changes the bladders from diabetic animals and the controls had similar characteristics with regard to nerve mediated frequency-response relations, atropine resistance, responses to alpha-agonists and high-K+ solution. No functional neurogenic lesion and no impairment of smooth muscle cell contractility could thus be detected, and it is proposed that the bladder hypertrophy in the diabetic animals is due to a physiological adaptation to the four-fold increase in urinary production.
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PMID:Detrusor smooth muscle in rats with alloxan-induced diabetes. 376 67

To further define the pathogenesis of diabetic connective tissue lesions, collagen synthesis and degradation were measured in vivo in spontaneously diabetic db/db mice. A double isotopic labeling technique, in which 14C-labeled and 3H-labeled proline were injected into the same mouse 7 days apart, was applied. Collagen synthesis and degradation were assessed in skins, intestines, hearts, and kidneys. There were no changes in collagen metabolism in the intestines of the diabetic mice. In all other tissues, collagen degradation was accelerated. Collagen synthesis was decreased in skins, but increased in the hearts and kidneys of the diabetic mice. These tissue-specific changes in collagen metabolism resulted in a net loss of collagen in all tissues examined except intestines. The results of this study provide insight into the mechanisms leading to connective tissue defects occurring in diabetes mellitus.
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PMID:In vivo collagen metabolism in spontaneously diabetic (db/db) mice. 377 Jan 46

The importance of cyclooxygenase and lipoxygenase pathways in the determination of collagen abnormalities in diabetes was investigated. Pharmacological agents with antiprostaglandin activity, such as indomethacin, naproxen, and aspirin, were able to prevent the rise in thermal rupture time of tail collagen in diabetic rats. Paracetamol was without effect. The action of indomethacin on diabetic collagen was abolished by concurrent administration of sodium benoxaprofen, an inhibitor of lipoxygenase, to the diabetic rats. Collagen abnormalities in diabetes may be regulated by a balance of the cyclooxygenase and lipoxygenase pathways. Antiprostaglandin agents may have a role in the prevention of some diabetic complications.
Diabetes 1985 Jan
PMID:The effects of cyclooxygenase and lipoxygenase inhibitors on the collagen abnormalities of diabetic rats. 391 59

Diabetes mellitus is associated with altered platelet function and endothelial damage, but their relationship remains unclear. We examined the effect of short-term metabolic control with insulin in 14- and 28-day streptozocin-induced diabetic rats on alterations in in vitro platelet aggregation and serotonin release. Endothelial damage was assessed by plasma concentrations of von Willebrand factor activity (VIIIR:WF) and factor VIII-related antigen (VIIIR:Ag). Insulin was administered for 5 or 7 days at 9 or 21 days, respectively, after streptozocin. Enhanced platelet aggregation responses to adenosine diphosphate (ADP) and thrombin occurred after both durations of diabetes. Insulin therapy returned ADP-induced, but not thrombin-induced, responses to normal. Enhanced thrombin-induced platelet release of serotonin occurred at both times. Collagen-induced platelet release was enhanced in 28-day diabetic rats. Insulin therapy returned these responses to normal. Plasma concentrations of VIIIR:WF and VIIIR:Ag were elevated in 28-day, but only VIIIR:WF was elevated in 14-day diabetic rats. Insulin therapy reduced the elevated levels of VIIIR:Ag in 28-day diabetic rats, but had little effect on either parameter after the shorter duration of diabetes. In summary, Enhanced platelet aggregation and increased release of serotonin occur shortly after the induction of diabetes by streptozocin in adult rats. These platelet changes precede alterations of endothelial function, as determined by plasma VIIIR:WF and VIIIR:Ag levels. Platelet changes respond more rapidly to insulin therapy than do endothelial changes in diabetic rats. The duration of diabetes before insulin therapy does not affect these relationships.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of insulin treatment in streptozocin-induced diabetic rats on in vitro platelet function and plasma von Willebrand factor activity and factor VIII-related antigen. 392 83

Forearm skin biopsies were obtained from diabetic subjects with and without limited joint mobility, and from non-diabetic control subjects. Collagen purified from these samples was assayed for non-enzymatic glycosylation. The level in all diabetic patients was significantly greater than that in control subjects (p less than 0.001), but those diabetic patients with limited joint mobility had a level of collagen glycosylation similar to that in those with normal joints (15.3 +/- 1.3 and 16.5 +/- 1.3 nmol fructose/10 mg protein, respectively; mean +/- SEM). Glycosylation of collagen in the diabetic patients correlated with glycosylated haemoglobin measured at the time of skin biopsy (r = 0.60). These results do not support the hypothesis that non-enzymatic glycosylation of collagen, as reflected by the ketoamine link, plays an important role in the development of limited joint mobility in diabetes.
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PMID:Non-enzymatic glycosylation of skin collagen in patients with type 1 (insulin-dependent) diabetes mellitus and limited joint mobility. 397 83

Glucose inhibits collagen fibril formation in vitro. A linear dose response was observed, with half-maximum inhibition of fibril formation occurring at 50 mM glucose. Nonfibrillar collagen cannot be cross-linked by lysyl oxidase, an enzyme that catalyzes the initial cross-linking reaction. The degree of decreased fibril formation correlated with the loss of ability of the collagen to serve as a substrate for lysyl oxidase. Collagen that is not cross-linked is unstable and more susceptible to collagenolytic attack. Interference with collagen cross-linking and more rapid degradation may explain the decreased amounts of interstitial collagen and the poor healing of wounds associated with diabetes mellitus.
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PMID:Inhibition of collagen fibril formation in vitro and subsequent cross-linking by glucose. 614 99

Five patients with maturity-onset diabetes mellitus and hepatomegaly were studied. This group in cluded moderately obese females in whom hepatomegaly and abnormal liver studies were associated with a marked elevation in the erythrocyte sedimentation rate. Liver biopsies from all 5 showed fatty steatosis and pericentral fibrosis. In 3 of the 5, fibrous bridging between central veins and portal tracts was present. Collagen surrounded swollen hepatocytes, some of which contained intracellular hyalin indistinguishable from Mallory's hyalin. Polymorphonuclear neutrophils and regenerating nodules were not present. None of the patients had a history of alcohol use, and in 2 followed closely for 2 yr, alcohol was never detected in random blood samples. The recognition of this morphologic lesion may help to clarify the significance of this finding as an intermediate lesion between fatty steatosis and cirrhosis in diabetics.
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PMID:Pericentral hepatic fibrosis and intracellular hyalin in diabetes mellitus. 615 66

Collagen catabolism has been measured in skins of streptozotocin-induced diabetic rats. For measuring catabolism of collagen synthesized de novo during the diabetic state, we measured the amounts of [3H]hydroxyproline-containing degradation products in skins of diabetic rats, killed 4 h after [3H]proline injection (protocol 1); degradation products were isolated in TCA-soluble fractions of skin homogenates. For measuring catabolism of collagen preexisting before the induction of the diabetic state, we measured the 21-day loss of [3H]hydroxyproline (and hydroxyproline) in entire skins of rats that were streptozotocin-treated after [3H]proline injection (protocol 2). A 2.5-fold increase in the relative amounts of [3H]hydroxyproline-containing degradation products was measured in the TCA-soluble fractions of skins from diabetic rats (protocol 1). These degradation products had a low molecular weight (as evident from their diffusibility), and they were derived from recently synthesized collagen, possibly procollagen (as evident from their high [3H]hydroxyproline specific activity). Furthermore, they were not derived from the degradation of [3H]hydroxyproline-labeled collagen present before induction of the diabetic state (protocol 2). Evidence for this conclusion is as follows: the amounts of [3H]hydroxyproline-containing degradation products in skins of diabetic rats were not greater than that in skins of control rats, despite a 50% resorption of collagen in skins of diabetic rats. Overall, the catabolism of collagen formed de novo during the diabetic state was distinguished from the catabolism of collagen formed before, and both catabolic processes were enhanced in rat skins of streptozotocin-induced diabetic rats.
Diabetes 1982 May
PMID:Skin collagen metabolism in the streptozotocin-induced diabetic rat. Enhanced catabolism of collagen formed both before and during the diabetic state. 621 1


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