页 1 从 31 结果
The question whether ascorbate regulates collagen production solely through its direct role in proline hydroxylation was investigated. Proteins in calvarial bones from control and scorbutic weanling guinea pigs were labeled in short-term cultures with radioactive proline. Proteins were digested with
1. The age-related decrease in hydroxyproline : creatinine ratio in young guinea pigs was significantly smaller in vitamin C-deficient animals than in pair-fed controls. The same was true for proline : creatinine and total amino nitrogen : creatinine ratios, but hydroxyproline : total amino nitrogen
Compared to homologous tissues from adult animals, rapidly growing embryonic and fetal tissues contain large amounts of collagen proline hydroxylase. Lung and skin from scorbutic guinea pigs contain one-third as much enzyme as normal tissues do. A rapid increase in proline hydroxylase occurs on the
1. The effect of ascorbic acid deficiency on glycosaminoglycans of granulation tissue and cartilage of guinea pigs was investigated by determination of the changes in the glucosamine and galactosamine contents 12 days after tendonectomy. 2. In normal granulation tissue, the glucosamine and
Several conifers have been considered as candidates for "Annedda", which was the source for a miraculous cure for scurvy in Jacques Cartier's critically ill crew in 1536. Vitamin C was responsible for the cure of scurvy and was obtained as an Iroquois decoction from the bark and leaves from this
Second maxillary molars of hamsters were cultured in the presence or absence of 250 micrograms/ml vitamin C for periods up to 12 days. At various days, cultured explants were studied with histological and biochemical methods to investigate effects of vitamin C-deficiency on matrix production and
1. Plasma and buffy-coat vitamin C, urinary proline, hydroxyproline, creatinine and total amino acid concentrations were meausred in 23 healthy elderly subjects at intervals of 3 months. 2. There was a strong positive correlation between plasma vitamin C and buffy-coat vititamin C. 3. There were not
Incorporation of labeled proline into liver and skin proteins of weanling rats was studied during zinc restriction. Reduced incorporation of labeled proline into skin proteins including collagen hydroxyproline and an increase in its incorporation into liver and plasma proteins was observed with 0 or
Our recent studies suggested that decreased collagen synthesis in bone and cartilage of scorbutic guinea pigs was not related to ascorbate-dependent proline hydroxylation. The decrease paralleled scurvy-induced weight loss and reduced proteoglycan synthesis. Those results led us to propose that the
Vitamin C deficiency is associated with defective connective tissue, particularly in wound healing. Ascorbate is required for hydroxylation of proline residues in procollagen and hydroxyproline stabilizes the collagen triple helical structure. Consequently, ascorbate stimulates procollagen
Iron (II)/2-oxoglutarate (2-OG)-dependent oxygenases catalyse oxidative reactions in a range of metabolic processes including the hydroxylation of proline and lysine residues during the post-translational modification of collagen. 2-OG oxygenases commonly require ascorbate for full activity. In the
Endoplasmic reticulum (ER) thiol oxidases initiate a disulfide relay to oxidatively fold secreted proteins. We found that combined loss-of-function mutations in genes encoding the ER thiol oxidases ERO1α, ERO1β, and PRDX4 compromised the extracellular matrix in mice and interfered with the
1. The synthesis of collagen in several tissues, including the C1q component of complement in serum, was measured in vitamin C-deficient and control guinea pigs by incorporating labelled proline into hydroxyproline in vivo. 2. Of the tissues examined, by far the greatest specific effect of vitamin C
The skin of severely scorbutic guinea pigs which were losing weight contained no detectible neutral salt-extractible collagen. Conditions of growth (weight gain) which actively induced the formation of neutral salt-extractible collagen in the skin of normal guinea pigs failed to do so in the animal
Vitamin C or ascorbic acid is a hydrosoluble vitamin derived from glucose metabolism. It acts as a reductor agent required for synthesis of collagen fibers through hydroxylation of proline and lysine. It also protects the body against damage caused by the free radicals. Humans cannot synthesize