Potassium deficiency

Sodium chloride is relatively inexpensive and is provided either free or incorporated directly into animal feed to prevent sodium and chloride deficiencies. Potassium is usually not deficient because most forages have adequate quantities. Therefore, it should be supplemented only when animals consume poor quaHty roughages or a high concentrate diet, or when they are under stress, dehydrated, or suffering from diarrhea (5). Potassium deficiency usually is alleviated by changing the diet or by supplementing with potassium sulfate. 

Distinguish symptoms of excess and deficient potassium imbalances. Identify diagnostic values associated with potassium imbalances. 

Pellagra is a disease caused by a deficiency of niacm (C6FI5NO2) in the diet Niacin can be synthesized in the laboratory by the side chain oxidation of 3 methylpyndine with chromic acid or potassium permanganate Suggest a reasonable structure for niacin... 

Other Potassium and Sodium Disorders. Potassium and/or sodium deficiency can lead to muscle weakness and sodium deficiency to nausea. Hyperkalemia resulting in cardiac arrest is possible from 18 g/d of potassium combined with inadequate kidney function. Faulty utilisation of K" and/or Na" can lead to Addison s or Cushing s disease. 

Iodized Salt. Iodized table salt has been used to provide supplemental iodine to the U.S. population since 1924, when producers, in cooperation with the Michigan State Medical Society (24), began a voluntary program of salt iodization in Michigan that ultimately led to the elimination of iodine deficiency in the United States. More than 50% of the table salt sold in the United States is iodized. Potassium iodide in table salt at levels of 0.006% to 0.01% KI is one of two sources of iodine for food-grade salt approved by the U.S. Food and Dmg Administration. The other, cuprous iodide, is not used by U.S. salt producers. Iodine may be added to a food so that the daily intake does not exceed 225 p.g for adults and children over four years of age. Potassium iodide is unstable under conditions of extreme moisture and temperature, particularly in an acid environment. Sodium carbonate or sodium bicarbonate is added to increase alkalinity, and sodium thiosulfate or dextrose is added to stabilize potassium iodide. Without a stabilizer, potassium iodide is oxidized to iodine and lost by volatilization from the product. Potassium iodate, far more stable than potassium iodide, is widely used in other parts of the world, but is not approved for use in the United States. 

USP XXII specifies that sodium iodide contains 99—101.5% Nal, calculated on an anhydrous basis (4). It is used iaterchangeably with potassium iodide as a therapeutic agent, except where sodium ion is contraindicated (see Potassium compounds). Intravenous sodium iodide formulations have been used for a variety of diseases, from thyroid deficiency to neuralgia (see Thyroid and antithyroid preparations). However, these solutions are no longer listed ia the XFXUII (4), iadicatiag that their therapeutic value has not been satisfactorily demonstrated. 

Hypoaldosteronism is defined as a deficiency of aldosterone. Renal secretion of potassium is decreased, causing hyperkalaemia. The treatment is replacement of a mineralocorticoid, e.g. fludrocortisone. 

The mineralocorticoids consist of aldosterone and des-oxycorticosterone and play an important role in conserving sodium and increasing die excretion of potassium. Because of diese activities, die mineralocorticoids are important in controlling salt and water balance Aldosterone is die more potent of these two hormones. Deficiencies of the mineralocorticoids result in a loss of sodium and water and a retention of potassium. 

Potassium iodide is added as a nutrient to prevent goiter, a thyroid problem caused by lack of iodine, and to prevent a form of mental retardation associated with iodine deficiency. A project started by the Michigan State Medical Society in 1924 promoted the addition of iodine to table salt, and by the mid-1950s three-quarters of U.S. households used only iodized salt. Potassium iodide makes up 0.06 percent to 0.01 percent of table salt by weight. Sometimes cuprous iodide—iodide of copper—is used instead as the source of iodine. 

Potassium is abundant in animal and plant cells (Birch and Pradgeham 1994). Hypokalemia (deficiency) and hyperkalemia (accumulation of K[I]) may both occur. As the normal range of K[I] in plasma is small, and the consequences of hyperkalemia fatal, the method of determination must be precise and accurate to detect lower and higher than normal levels (hypokalemia and hyperkalemia, respectively). The preferred method of determination is PISE. 

Cakmak, C. Hengeler, and H. Manschner, Changes in phloem export of sucrose in leaves in response to phosphorus, potassium and magnesium deficiency in beau plants. J. Exp. Bot. 45 1251 (1994). 

Nutrient deficiencies may also influence the production of allelochemics. The compounds studied in great detail have been the phenolic compounds and scopolin-related chemicals. Deficiencies of boron, calcium, magnesium, nitrogen, phosphorus, potassium, and sulfur have all been reported to enhance the concentration of chlorogenic acids and scopolin in a variety of plants (4). In other species, chlorogenic acids have decreased in plants that are deficient in magnesium or potassium. 

Joho, R. H., Ho, C. S. Marks, G. A. (1999). Increased gamma - and decreased delta -oscillations in a mouse deficient for a potassium channel expressed in fast-spiking interneurons. J. Neurophysiol. 82, 1855-64. 

Evaporation of a solution of hexachloroplatinic acid with a deficiency of potassium azide, or with an equivalence of ammonium azide gives explosive residues. Evaporation of a solution of the acid with an equivalence (8 mol) of potassium azide leads to explosion of the cone, solution of the title compound. 

Although the base-catalyzed addition of nitroalkanes to electron-deficient olefins has been extensively used in organic synthesis (see Michael addition Chapter 4), it is only recently that the reaction has been extended to the cyclopropanation reaction. In 1978, it was reported that the anion of nitromethane reacts with certain highly electron-deficient olefins to produce cyclopropanes in good yield (Eq. 7.36).36 More recently, this reaction has been extended to more general cyclopropanations, as shown in Eqs. 7.37 and 7.38, in which potassium salts of nitroalkanes are employed in DMSO as alkylidene transfer reagents.37-39... 

Weed competition for water and nutrients can have similar effects on fruit quality as described above for fertilisation. For example, if weed competition is completely prevented by chemosynthetic herbicides in conventional production, this can lead to excess supply of certain mineral nutrients, in particular nitrogen and potassium, which in turn results in reduced sensory quality and shelf-life (Section 16.2.2). On the other hand, excessive weed competition, in particular, during the pre-bloom phase and the end of the first shoot growth period (Gut and Weibel, 2005), can induce nutrient and/or water deficiency and a risk of quality loss. 

The osmium-catalyzed dihydroxylation reaction, that is, the addition of osmium tetr-oxide to alkenes producing a vicinal diol, is one of the most selective and reliable of organic transformations. Work by Sharpless, Fokin, and coworkers has revealed that electron-deficient alkenes can be converted to the corresponding diols much more efficiently when the pH of the reaction medium is maintained on the acidic side [199]. One of the most useful additives in this context has proved to be citric acid (2 equivalents), which, in combination with 4-methylmorpholine N-oxide (NMO) as a reoxidant for osmium(VI) and potassium osmate [K20s02(0H)4] (0.2 mol%) as a stable, non-volatile substitute for osmium tetroxide, allows the conversion of many olefinic substrates to their corresponding diols at ambient temperatures. In specific cases, such as with extremely electron-deficient alkenes (Scheme 6.96), the reaction has to be carried out under microwave irradiation at 120 °C, to produce in the illustrated case an 81% isolated yield of the pure diol [199]. 

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