Metabolism fiber

Plant cells and animal cells share most of the same metabolic systems, and with a few exceptions, plants require the same array of nutrients as animals. Most of this overlap occurs in the macrominerals and some microminerals. But plants also have their own special needs for elements that our livestock cannot use, like boron, which is involved in fiber metabolism, and molybdenum, which is used in nitrogen metabolism and nitrogen fixation. But what about the three minerals that plants don t need—iodine, cobalt, and selenium ... 

Roberts E.M., Nunna R.R., Huang J.Y, Trolinder N.L., and Haigler C.H. 1992. Effects of cycling temperatures on fiber metabolism in cultured cotton ovules. Plant Physiol 100 979-986. 

The use of foods by organisms is termed nutrition. The ability of an organism to use a particular food material depends upon its chemical composition and upon the metabolic pathways available to the organism. In addition to essential fiber, food includes the macronutrients—protein, carbohydrate, and lipid—and the micronutrients—including vitamins and minerals. 

Measurements of metabolite concentrations in muscle fibers before and after fatiguing stimulation have shown that ATP decreases from 6 to 4.6 mM and PCr decreases from 35 to 2.4 mM with a calculated increase in Pj from 3 to 38 mM (Dawson et al., 1978 Nassar-Gentina et al., 1978). The free ADP concentration was calculated to increase from 30 to 200 pM. At the same time pH decreased from 7.0 to 6.5 (Dawson et al., 1978 Juel, 1988 Westerblad and Lannergren, 1988). The effect of these metabolic changes has been studied in skinned muscle fibers, i.e., fibers in which the cell membrane has been removed. The skinning of the fibers... 

It is generally accepted that the two main fiber types have different metabolic profiles with higher activities of Ca activated myosin ATPase, creatine kinase. 

Nassar-Gentina, V., Passonneau, J.V., Rapoport, S.I. (1981). Fatigue and metabolism of frog muscle fibers during stimulation and in response to caffeine. Am. J. Physiol. 241, CI60-C166. 

Diseases affecting skeletal muscle are not always primary diseases of muscle, and it is necessary first to determine whether a particular disorder is a primary disease of muscle, is neurogenic in origin, is an inflammatory disorder, or results from vascular insufficiency. A primary disease of muscle is one in which the skeletal muscle fibers are the primary target of the disease. Neurogenic disorders are those in which weakness, atrophy, or abnormal activity arises as a result of pathological processes in the peripheral or central nervous system. Inflammatory disorders may result in T-cell mediated muscle damage and are often associated with viral infections. Vascular insufficiency as a result of occlusion in any part of the muscle vasculature can cause severe disorders of muscle, especially in terms of pain, metabolic insufficiency, and weakness. 

Histopathological examination shows the typical corelike lesions in a high proportion of muscle fibers in older patients this may amount to 100%. Most typically the cores are large and centrally-placed, but multiple cores may occur in the same fiber cross section. Most older patients show a striking predominance of type 1 (slow twitch oxidative) fibers and virtually all fibers with cores are type 1. Sometimes younger family members have more normal proportions of type 1 and type 2 fibers but, again, the cores are confined to the type 1 fibers. It is well established that muscle fiber types can interconvert due to altered physiological demands, and it is likely that fibers with cores convert to a basically slow twitch-oxidative metabolism to compensate for the fact that up to 50% of their cross sectional area may be devoid of mitochondria. 

Biopsy findings show disseminated muscle fiber atrophy which is confined to type 2 fibers, in many instances with type 2B (glycolytic) fibers most affected (Figure 23). Muscle necrosis is not seen, though at ultrastructural level focal myofibrillar disruption and myofilament loss may be evident. The muscle atrophy seems to be due to decreased protein synthesis, and at high doses, to increased catabolism. The reason for the selective effect on phasic, glycolytic fibers is not clear since, although steroids interfere with carbohydrate metabolism and oxidative capacity, there seems to be no overall effect on ATP levels. Nevertheless it has been... 

Primary hyperparathyroidism occurs as a result of hyperplasia or the occurrence of adenoma. Secondary hyperparathyroidism may result from renal failure because of the associated phosphate retention, resistance to the metabolic actions of PTH, or impaired vitamin D metabolism. The last-mentioned factor is primarily responsible for the development of osteomalacia. Muscle symptoms are much more common in patients with osteomalacia than in primary hyperparathyroidism. Muscle biopsy has revealed disseminated atrophy, sometimes confined to type 2 fibers, but in other cases involving both fiber types. Clinical features of osteomalacic myopathy are proximal limb weakness and associated bone pain the condition responds well to treatment with vitamin D. 

Adiotomre, Eastwood, M. A. Edwards, C. A. Brydon, W. G. (1990). Dietary fiber in vitro methods that anticipate nutrition and metabolic activity in humans. American Journal of Clinical Nutrition, Vol.52, No.l, Qanuary 1990), pp. 128-134, ISSN 0002-9165. 

Besides water, the diet must provide metabolic fuels (mainly carbohydrates and lipids), protein (for growth and turnover of tissue proteins), fiber (for roughage), minerals (elements with specific metabolic functions), and vitamins and essential fatty acids (organic compounds needed in small amounts for essential metabolic and physiologic functions). The polysaccharides, tri-acylglycerols, and proteins that make up the bulk of the diet must be hydrolyzed to their constituent monosaccharides, fatty acids, and amino acids, respectively, before absorption and utilization. Minerals and vitamins must be released from the complex matrix of food before they can be absorbed and utifized. 

Besides watet, the diet must provide metaboEc fuels (carbohydrate and fat) fot bodily growth and activity protein fot synthesis of tissue proteins fiber for roughage minerals for specific metabolic functions cettain polyunsamtated fatty acids of the n-3 and n-6 famihes fot eicosanoid synthesis and other functions and vitamins, otganic compounds needed in small amounts for many varied essential functions. 

Substantial individual differences were observed in the response to study breads and the ranges of enterolactone concentration changes in the groups were as follows -54.5-60.0 nmol/1 (placebo), -26.2-101.3 nmol/1 (LP), -19.6-81.8 nmol/1 (HP). This was something that could have been expected as in several studies dietary factors have explained only 10% of the variation in serum enterolactone (Vanharanta et al, 2002b Kilkkinen et al., 2001). This gives further support to the major role of intestinal bacteria in the synthesis of enterolactone. Decreased concentrations of enterolactone may occur due to an increased fiber intake, which may shorten the retention time in the colon and lead to incomplete metabolism of plant lignans. Constipation was earlier shown to be associated with an increased level of serum enterolactone (Kilkkinen et al., 2001). 

STORY J A, KRITCHEVSKY D (1976) Dietary fiber and lipid metabolism. In Fiber in Human Nutrition Eds Spiller G A, Amen R J, New York Plenum Press, 171-84. 

WOLVER T M s, JENKINS D J A (1993) Effect of dietary fiber and foods on carbohydrate metabolism. Dietary Fiber in Nutrition. In Ed. Spiller G A, Boca Raton, FL CRC Press. 111-52. 

Osorio-Lozada, A., Surapaneni, S., Skiles, G. and Subramanian, R. (2008) Biosynthesis of drug metabolites using microbes in hollow fiber cartridge reactors case study of diclofenac metabolism by Actinoplanes sp. Drug Metabolism and Disposition The Biological Fate of Chemicals, 36, 234-240. 

Finally, it should also be considered that flavonoid-rich foods contain a great diversity of compounds with bioactive properties (for e.g., carotenoids, other phenolics, fiber, and minerals), and multiple interactions occur among all of them. There is also great diversity in the ingestion, absorption, and metabolism of these compounds in different populations, and all of these circumstances could camouflage any effect of flavonoids on disease prevention or treatment. 

Leontowicz M, Gorinstein S, Bartnikowska E, Leontowicz H, Kulasek G and Trakhtenberg S. 2001. Sugar beet pulp and apple pomace dietary fibers improve lipid metabolism in rats fed cholesterol. Food Chem... 

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