Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036474 (scurvy)
 685 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

BACKGROUND: Latent tissue scurvy in clinical and experimental ascorbic acid (AA) deficiency resembles diabetic microangiopathy as reflected in capillary hyperperfusion and increased transcapillary escape rate (TER), von Willebrand factor (vWf), and capillary fragility (CF). We aimed to investigate the possible clinical impact of the low plasma AA level observed in type 1 diabetes mellitus. METHODS: Twenty normoalbuminuric patients with retinopathy were included in a randomized, double-blinded, placebo-controlled 6-month study with AA (6 g/day; n=10, mean age+/-S.D. 35.3+/-8.5 years, diabetes duration 17.2+/-3.3 years) or placebo (n=10; mean age 37.8+/-6.6 years, diabetes duration 18.4+/-1.7 years). RESULTS: An inverse correlation between log plasma AA (HPLC method) and TER of (125)I-labelled albumin was found (r=-0.66, p=0.002). TER decreased in the AA-treated group from 6.8+/-1.0 to 5.4+/-1.5%/h compared to the unchanged placebo group (from 5.6+/-1.5 to 5.9+/-1.1%/h; p=0.031). The CF (capillary resistance test) decreased in the AA group compared to the placebo group (p=0.028), while vWf, fibrinogen and fibronectin levels, and glomerular filtration rate (clearance of (125)I-iothalamate) remained unchanged. CONCLUSIONS: The results suggest that a low plasma AA level might be associated (pathogenetic?) with development of microangiopathy in type 1 diabetes mellitus and points to a possible treatment modality.
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PMID:Vitamin C treatment reduces transcapillary escape rate of albumin in type 1 diabetes. 1558 46

Poor wound healing during vitamin C deficiency is thought to be due to decreased hydroxylation of proline residues in collagen. In non-repair connective tissues of guinea pigs, however, procollagen gene expression is not decreased until weight loss occurs during the third and fourth weeks of scurvy (phase II) with only a moderate decrease in proline hydroxylation. Decreased procollagen gene expression is related to the induction of insulin-like growth factor binding proteins 1 and 2 that inhibit insulin-like growth factor-I action. We examined wound healing and granulation tissue formation during phase I of vitamin C deficiency. Synthetic sponges were implanted on day 7 of vitamin C deficiency and analyzed at 6 and 10 days after surgery, when there was no weight loss or induction of insulin-like growth factor binding proteins. Healing of incisions was almost complete at 10 days after surgery in normal controls but not in scorbutic animals. The area around the incision and implant exhibited excessive angiogenesis and hemorrhaging of vessels in the scorbutic animals at 6 and 10 days after surgery. At 10 days after surgery, collagen synthesis in the implants of scorbutic guinea pigs was 36% lower than control values, with a normal extent of proline hydroxylation. Concentrations of messenger RNAs for types I and III procollagens were slightly increased by scurvy at 6 days after surgery but were decreased by 26% and 40%, respectively, at 10 days. Fibronectin mRNA levels were unaffected by scurvy at both time points. Our results suggest that poor wound healing in phase I of scurvy may be related to defective interstitial procollagen gene expression and defective blood vessel formation, but it does not involve inhibition of proline hydroxylation or induction of insulin-like growth factor binding proteins. mRNA for insulin-like growth factor-II, transforming growth factor-beta(1), and transforming growth factor-beta(2) were significantly expressed in implants, but their patterns of expression did not correlate with changes in procollagen gene expression.
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PMID:Differential regulation of collagen gene expression in granulation tissue and non-repair connective tissues in vitamin C-deficient guinea pigs. 1717 48