glycogen and Vitamin-A-Deficiency

This study assesses the impact of various forms of injury on matrix degrading enzymes in nutritionally compromised rat corneas. In vitamin A-deficient (nutritionally compromised) and normal control corneas, in vivo or ex vivo mild mechanical abrasion did not appreciably alter the activity of either the 65-kDa or the 92-kDa gelatinases. In contrast, after thermal injury, while no appreciable change was detected in activity associated with the 65-kDa gelatinase in either vitamin A-deficient or normal control corneas, 92-kDa gelatinolytic activity was consistently higher in corneas from both groups, although activity associated with nutritionally compromised corneas was much higher. In these corneas, thermal injury also induced the expression of two high molecular weight (approximately 130-kDa and 225-kDa) gelatinases and a 27-kDa caseinase. While gelatinases were totally inactivated by inhibitors of metalloproteinases such as 1,10-phenanthroline and Galardin MPI, the 27-kDa caseinase showed considerable susceptibility to a mixture of serine protease inhibitors (aprotinin, dichloro-isocoumarin and pA-PMSF [(4-amidino-phenyl)-methane-sulphonyl fluoride]. Furthermore, unactivated-lymphoreticular cells from either nutritionally compromised or normal control animals contained a 24- and 27-kDa caseinase, however most of the activity was due to the 24-kDa caseinase. In contrast, glycogen-activated lymphoreticular cells contained a preponderance of the 27-kDa caseinase. Activated-lymphoreticular cells also expressed 92-kDa, 130-kDa and 225-kDa gelatinases. The presence of low molecular weight caseinases in lymphoreticular cells implicates them as the source of these enzymes.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Cornea; Corneal Injuries; Corneal Ulcer; Eye Injuries; Gelatinases; Glycogen; Male; Metalloendopeptidases; Peptide Hydrolases; Rats; Rats, Sprague-Dawley; Reticulocytes; Vitamin A Deficiency

The effect of the dietary status of vitamin A on carbohydrate metabolism, postmortem isometric tension development, and shear resistance of Pectoralis major muscle was studied. Depletion studies conducted over a 5-week period indicated a definite influence of vitamin A deficiency on muscle carbohydrate metabolism. Mild hypovitaminosis A induced an increase in glycogen deposition, whereas severe deficiency led to a reduction of these elevated stores. Vitamin A deficiency did not affect the ability of P. major strips to develop isometric tension postmortem. The P. major strips sampled from deficient cockerels generally required longer to reach maximum tension than those of controls. The extended times to maximum tension reflected an increased muscle glycogen content. A significant increase in shear value similarly corresponded to the increased myofibrillar contraction noted in the later deficiency stages. Cockerels which had previously received for five weeks a ration completely deficient in vitamin A were utilized for a two-week repletion study. Although there was a distinct delay in response to the feeding of a vitamin A adequate ration, the muscle glycogen content, isometric tension parameters, and shear values of repleted birds were similar to those of controls within the two-week period.

Topics: Adenosine Triphosphate; Animals; Chickens; Glycogen; Male; Muscle Contraction; Muscles; Poultry Diseases; Vitamin A Deficiency

Topics: Acetylcholine; Amino Acids; Animals; Cattle; Conjunctiva; Cornea; Corneal Diseases; Diabetes Mellitus; Epithelium; Glucose; Glycogen; Humans; Rabbits; Tears; Vitamin A Deficiency

Topics: Animals; Blood Glucose; Carbon Dioxide; Chickens; Glucose; Glycogen; Kinetics; Liver; Liver Glycogen; Male; Muscles; Oxidation-Reduction; Vitamin A Deficiency

Topics: Administration, Oral; Adrenal Glands; Animal Feed; Animals; Ascorbic Acid; Blood Glucose; Body Weight; Carbohydrate Metabolism; Chickens; Corticosterone; Female; Glycogen; Male; Organ Size; Poultry Diseases; Vitamin A; Vitamin A Deficiency

Topics: Adenosine Triphosphate; Animals; Blood Glucose; Body Weight; Carbohydrate Metabolism; Catecholamines; Chickens; Glucosyltransferases; Glycogen; Lactates; Liver; Liver Glycogen; Pectoralis Muscles; Poultry Diseases; Vitamin A Deficiency

Topics: Epithelium; Female; Glycogen; Glycogenolysis; Humans; Uterus; Vitamin A Deficiency