Deficiency enzyme changes

Today, biochemical deficiency of riboflavin is accepted in the absence of clinical signs of deficiency. Biochemical signs of deficiency include change in the amount of the vitamin which is excreted in the urine, or change in the level of activity of a red blood cell (erythrocyte) enzyme, which is known as the erythrocyte glutathione reductase. Requirements for the vitamin are defined as that amount which will prevent both clinical and biochemical signs of deficiency. 

Butterworth RF (2006) Metabolic Encephalopathies. In Siegel GJ, Albers RW, Brady ST, Price DL (eds) Basic neurochemistry, 7th edn. Elsevier, London, pp 593-602 Butterworth RF, Besnard AM (1990) Thiamine-dependent enzyme changes in temporal cortex of patients with Alzheimer s disease. Metab Brain Dis 5(4) 179-184 Butterworth RF, GaudreauC, Vincelette J, Bouigault AM, LamotheF, Nutini AM (1991) Thiamine deficiency and Wernicke s encephalopathy in AIDS. Metab Brain Dis 6(4) 207-212 Butterworth RF, Heroux M (1989) Effect of pyrithiamine treatment and subsequent thiamine rehabilitation on regional cerebral amino acids and thiamine-dependent enzymes. J Neurochem 52(4) 1079-1084... 

Enzyme Changes in Zinc Deficiency. Since zinc is required for many enzymes, it is reasonable to speculate that the level of zinc in cells controls the physiological processes through the formation and/or regulation of activity of zinc-dependent enzymes. Until 1965, there was no evidence in the literature to support this concept. During the past decade it has been shown that the activity of various zinc-dependent enzymes was reduced in the testes, bones, esophagus, and kidneys of zinc-deficient rats in comparison with their pair-fed controls (90,91,100,101), These results correlated with the decreased zinc content in the above tissues... 

Nickel, Ni a metai present only in traces in living systems. In particular, it seems to be associated with RNA. A nickei metalloprotein, named nickeloplas-min has been isolated from human and rabbit serum, but its function is not known. Ni protects the structure of the ribosome against heat denaturation, and it restores the sedimentation characteristics of E. coli ribosomes that have been denatured by EDTA. Ni can activate some enzymes in vitro, e.g. deoxyribonuclease, acetyl CoA synthetase and phosphoglucomu-tase. Ni deficiency causes changes in the ultrastructure of the liver and alters the level of cholesterol in the liver membranes. It may be important in the regulation of prolactin. 

Enzymic changes in tissues other than the erythron and the epithelia have also been reported in iron deficiency the levels of iron-containing proteins—such as myoglobin, cytochrome, catalase, and others—are reduced. But the decrase in cytochrome activity must affect only the enzyme reserves because it is not accompanied by a corresponding decrease in oxygen uptake. 

Copper is required for all forms of aerobic and most forms of anaerobic life. In humans, the biological function of copper is related to the enzymatic action of specific essential copper proteins (66). Lack of these copper enzymes is considered a primary factor in cerebral degeneration, depigmentation, and arterial changes. Because of the abundance of copper in most human diets, chemically significant copper deficiency is extremely rare (67). 

Figure 5 Model of phosphorus (P) deficiency-induced physiological changes associated with the release of P-mobilizing root exudates in cluster roots of white lupin. Solid lines indicate stimulation and dotted lines inhibition of biochemical reaction sequences or mclaholic pathways in response to P deliciency. For a detailed description see Sec. 4.1. Abbreviations SS = sucrose synthase FK = fructokinase PGM = phosphoglueomutase PEP = phosphoenol pyruvate PE PC = PEP-carboxylase MDH = malate dehydrogenase ME = malic enzyme CS = citrate synthase PDC = pyruvate decarboxylase ALDH — alcohol dehydrogenase E-4-P = erythrosc-4-phosphate DAMP = dihydraxyaceConephos-phate APase = acid phosphatase.

Iron appeared to reduce the effects of orally or subcutaneously administered lead on blood enzyme and liver catalase activity (Bota et al. 1982). Treatment of pregnant hamsters with iron- or calcium-deficient diets in conjunction with orally administered lead resulted in embryonic or fetal mortality and abnormalities (ranting, edema) in the litters, while treatment with complete diets and lead did not (Carpenter 1982). Inadequate levels of iron in association with increased body burdens of lead enhanced biochemical changes associated with lead intoxication (Waxman and Rabinowitz 1966). Ferrous iron was reported to protect against the inhibition of hemoglobin synthesis and cell metabolism by lead it has been speculated that iron competes with lead uptake by the cell (Waxman and Rabinowitz 1966). In... 

The discussion of the clinical implications of G-6-PDH and 6-PGDH will be divided into two sections change of activities caused by diseases, and disorders caused by deficiency of enzymes. 

CH 10 METABOLISM OF AMMONIA AND NUCLEIC ACIDS Table 10.5 Changes in the concentration of various intermediates of the urea cycle or their metabolites in plasma or urine in various enzyme deficiency diseases in humans ... 

The terminology vitamin Bg covers a number of structurally related compounds, including pyridoxal and pyridoxamine and their 5 -phosphates. Pyridoxal 5 -phosphate (PLP), in particular, acts as a coenzyme for a large number of important enzymic reactions, especially those involved in amino acid metabolism. We shall meet some of these in more detail later, e.g. transamination (see Section 15.6) and amino acid decarboxylation (see Section 15.7), but it is worth noting at this point that the biological role of PLP is absolutely dependent upon imine formation and hydrolysis. Vitamin Bg deficiency may lead to anaemia, weakness, eye, mouth, and nose lesions, and neurological changes. 

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