ascorbic-acid and Bone-Diseases--Developmental

Topics: Adult; Age Factors; Anemia; Animals; Ascorbic Acid; Ascorbic Acid Deficiency; Bone Diseases, Developmental; Capillaries; Child; Collagen Diseases; Connective Tissue; Creatinine; Dentin; Gingival Hemorrhage; Hemorrhage; Humans; Hydroxyproline; Infant; Scurvy; Skin Diseases; Species Specificity

Ascorbic acid is a small-molecule reductant with multiple functions in vivo. Reducing ascorbic acid intake leads to a lack of hydroxylation of prolines and lysines, causing a looser triple helix and resulting in scurvy. Ascorbic acid also acts as an antioxidant to prevent oxidative stress. Because ascorbic acid is related to disease states, rapid and convenient detection of ascorbic acid should be useful in diagnosis. Nitroxide is reduced to the corresponding hydroxylamine by ascorbic acid and a sensitive and novel approach to its detection employs covalent coupling of nitroxide with a fluorophore, leading to intramolecular quenching of fluorescence emission by electron-exchange interactions. Here, we developed a new fluorophore-nitroxide probe, Naph-DiPy nitroxide, for ascorbic acid. Naph-DiPy nitroxide rapidly reacted with ascorbic acid and showed fluorescence enhancement, but not in response to other reductants or reactive oxygen species. To confirm the practical usefulness of the fluorophore-nitroxide probe, we demonstrated the use of Naph-DiPy nitroxide for the measurement of ascorbic acid in the plasma of osteogenic disorder Shionogi rats when fed an ascorbic acid-deficient diet. The results suggest that this novel fluorophore-nitroxide probe could sensitively and easily detect ascorbic acid and be useful as a tool for the diagnosis of disease states.

Topics: 1-Naphthylamine; Animals; Antioxidants; Ascorbic Acid; Blood Chemical Analysis; Bone Diseases, Developmental; Cyclic N-Oxides; Fluorescent Dyes; Free Radicals; Male; Oxidants; Rats; Scurvy

Trichlorobiphenyl induced only CYP1A2 mRNA, while pentachlorobiphenyl induced both CYP1A2 and CYP2B1 mRNAs in rat liver. The mRNA levels for these P450s were elevated when ascorbic acid-deficient ODS rats (mutant rats with a hereditary osteogenic disorder) were fed a diet supplemented with ascorbic acid. The amount of CYP2B1 mRNA increased rapidly and reached a maximum level of approximately double within 24 hr of injection of pentachlorobiphenyl. Thereafter, the amount of its mRNA decreased to a steady level. This pattern was roughly paralleled by changes in the amount of CYP1A2 mRNA.

Topics: Animals; Ascorbic Acid; Ascorbic Acid Deficiency; Bone Diseases, Developmental; Cytochrome P-450 Enzyme System; Enzyme Induction; Isoenzymes; Liver; Male; Polychlorinated Biphenyls; Rats; Rats, Mutant Strains; RNA, Messenger

Highly sensitive assay method of L-gulono-gamma-lactone oxidase (GLO) was constructed. In this method, L-ascorbic acid formed in the enzymatic reaction was converted to its bis(dinitrophenyl)hydrazone derivative, and the amount of the latter was determined by high-performance liquid chromatography. Twenty picomoles of ascorbic acid was detected, which makes this method 25 times more sensitive than the previously used dipyridyl one. By the present method, a minute activity of GLO in liver microsomes prepared from rats of the Osteogenic Disorder Shionogi strain (ODS-od/od) could be measured.

Topics: Animals; Ascorbic Acid; Bone Diseases, Developmental; Kinetics; L-Gulonolactone Oxidase; Microchemistry; Microsomes, Liver; Rats; Rats, Mutant Strains; Sugar Alcohol Dehydrogenases

Plasma ascorbic acid (PAA) in normal Labrador Retriever dogs less than one year of age averaged 1.22 +/- 0.05 mg/dl (x +/- sem) and was significantly higher than the value of 0.89 +/- 0.03, for Labrador Retrievers two years of age and older. No significant diurnal variation in PAA was observed. Oral or intravenous administration of 0.5 or 1.0 g of ascorbic acid (AA) elevated PAA for less than 8 hours. Injection of ACTH caused a significant decline in PAA for the initial 2 days, with variable results thereafter. Labrador Retriever puppies fed a ration high in protein, energy and calcium developed the typical skeletal diseases of overnutrition, including hypertrophic osteodystrophy (HOD). The addition or oral AA (0.5 g twice daily) had no ameliorating effect on the skeletal lesions. Instead AA supplementation resulted in relatively higher serum calcium values which, presumably by enhanced hypercalcitoninism, decreased bone resorption. Thus, AA treatment of dogs with HOD is contraindicated, as it can only aggravate the osseous lesions of HOD. The decreased PAA reported in dogs with HOD is interpreted to be the result of stress from pain.

Topics: Adrenocorticotropic Hormone; Animals; Ascorbic Acid; Ascorbic Acid Deficiency; Body Weight; Bone Diseases, Developmental; Calcium; Cortisone; Dog Diseases; Dogs; Humerus

A five year old girl presented with short femora, cupped distal metaphyses and flexion deformity of the knees suggesting previous epiphyseo-metaphyseal damage. The aetiology was suggested by finding a history of previous infantile scurvy with separated distal femoral epiphyses. The rarity of this complication and possible contributing factors are discussed.

Topics: Ascorbic Acid; Bone Diseases, Developmental; Child, Preschool; Epiphyses; Female; Humans; Infant; Radiography; Scurvy; Tibia

Topics: Animals; Ascorbic Acid; Ascorbic Acid Deficiency; Bone Diseases, Developmental; Dog Diseases; Dogs; Female; Male; Radiography; Radius

Topics: Animals; Ascorbic Acid; Bone Diseases; Bone Diseases, Developmental; Bone Diseases, Metabolic; Dog Diseases; Dogs; Medical Records