Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.14.11.2 (prolyl hydroxylase)
 1,814 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of an 8-day intravenous infusion of dexamethasone (7.6 mg kg-0.75 body weight) on collagen biosynthesis and wool growth in skin were examined in four Merino wethers. Plasma dexamethasone concentrations reached their peaks during the first 24 h infusion, which were followed by relatively stable levels (c. 1 X 10(-7) M) for the next 4--5 days. Minor increases in plasma dexamethasone levels were recorded during the final 2 days of treatment. Dexamethasone concentrations quickly fell below the level of detection once infusion ceased. Marked decreases in the wet weight, thickness and protein content of skin were observed at the end of infusion. DNA content was reduced to 42.4 +/- 4.9% s.e.m. during the first 2 days of treatment, but in the next 4 days of infusion gradually increased to 85.0 +/0 12.5% of controls. The level of collagen (expressed as hydroxyproline content of its acid hydrolysate) was elevated throughout the infusion and then gradually declined in 3 weeks to about 60% of controls. The biosynthesis of collagen measured by the rate of [14C]hydroxyproline formation and the activity of proline, 2-oxoglutarate dioxygenase (EC 1.14.11.2. formerly prolyl hydroxylase) was reduced during the first half of treatment to a greater extent than the rate of [14C]proline incorporation into proteins. Wool growth was reduced by 80.4 +/- 11.6% in the post-infusion period which allowed three sheep out of four to be defleeced. Inhibition of collagen biosynthesis in sheep skin was due initially to a decrease in the activity of proline, 2-oxoglutarate dioxygenase and later to the reduced rate of proline incorporation into proteins. It was also evident that changes in biosynthetic rate of collagen were not reflected in the total level of skin collagen. The extent of wool growth depression in individual animals paralleled the changes in DNA content and the extent of collagen biosynthesis inhibition.
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PMID:Effect of intravenously infused dexamethasone on collagen metabolism in skin of merino sheep. 23 81

The in vitro effects of dexamethasone on condylar cartilage from normal newborn mice were tested by measuring protein and DNA content, collagen synthesis, prolyl hydroxylase activity, collagen chains and by immunofluorescence the localization of type I and II collagen and fibronectin. The biochemical assays were complemented by structural studies of hormone-treated and control cultured specimens. It became apparent that both the protein and DNA content of the tissue decreased immediately following the addition of dexamethasone of the incubation system. Protein synthesis was significantly decreased by the hormone by 24 h. The degree of collagen hydroxylation was decreased by 24 h. Dexamethasone-treated condyles did not reveal a significant increase in the percentage of cold hydroxyproline of the total protein. Using the indirect immunofluorescence method, hormone-treated condyles revealed an enhancement of positive reactivity for type I collagen and fibronectin. SDS-gel electrophoresis of 3H-labeled collagen chains isolated by CM-cellulose chromatography indicated that dexamethasone did not significantly affect the ratios of the collagen chains. For further characterization, each chain was subjected to cyanogen bromide cleavage showing that the peptide maps of alpha 1(I) and alpha 1(II) chains were not different in dexamethasone-treated tissues in comparison to controls.
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PMID:Dexamethasone impairs growth and collagen synthesis in condylar cartilage in vitro. 284 91