Potassium Consumption Research Articles

Blood pressure and nutrient intake in the United States.

A data base of the National Center for Health Statistics, Health and Nutrition Examination Survey I (HANES I), was used to perform a computer-assisted, comprehensive analysis of the relation of 17 nutrients to the blood pressure profile of adult Americans. Subjects were 10,372 individuals, 18 to 74 years of age, who denied a history of hypertension and intentional modification of their diet. Significant decreases in the consumption of calcium, potassium, vitamin A, and vitamin C were identified as the nutritional factors that distinguished hypertensive from normotensive subjects. Lower calcium intake was the most consistent factor in hypertensive individuals. Across the population, higher intakes of calcium, potassium, and sodium were associated with lower mean systolic blood pressure and lower absolute risk of hypertension. Increments of dietary calcium were also negatively correlated with body mass. Even though these correlations cannot be accepted as proof of causation, they have implications for future studies of the association of nutritional factors and dietary patterns with hypertension in America.

Inhibitory effect of unconjugated bilirubin on [formula omitted] transport in rat kidney cortex slices

(1) The effects of unconjugated bilirubin on the accumulation of p- aminohippurate , kinetics of p- aminohippurate uptake, the efflux of pre-accumulated p- aminohippurate and water and electrolyte distribution were investigated in the rat kidney cortical slice. (2) The addition of unconjugated bilirubin to the incubation medium decreased the 60 min slice-to-medium concentration ratio of p- aminohippurate . (3) The decrease in p- aminohippurate accumulation by unconjugated bilirubin was found to be more pronounced by increasing the concentration of pigment in the medium. (4) The rate of uptake of p- aminohippurate as a function of p- aminohippurate concentration differed in aerobiosis and anaerobiosis, and unconjugated bilirubin decreased only the uptake of p- aminohippurate in aerobic conditions. (5) The efflux of pre-accumulated p- aminohippurate decreased when unconjugated bilirubin concentration in the medium was low (10–20 μM) but the efflux increased when the concentration of pigment was much higher (100 μM). (6) The addition of unconjugated bilirubin to the medium (40–100 μM) increased intracellular sodium and total tissue water content, and decreased intracellular potassium and oxygen consumption of tissue. However the slices incubated with low concentration of pigment (20 μM) did not exhibit significative changes in cellular functional parameters. (7) These findings suggest that unconjugated bilirubin impairs p- aminohippurate transport by a complex mechanism that might involve binding of pigment to sites necessary for anion transport, although effects related to pigment toxicity or to its oxidative decomposition are not excluded.

Zinc status of vegetarians

The zinc status of seventy-nine vegetarians and forty-one non-vegetarians was investigated. The subjects provided 24-hr. dietary recalls and donated samples of blood, hair, and saliva that were subsequently analyzed for zinc content. Avoidance of animal products in the diet was associated with decreased intakes of energy, protein, fat, calcium, and zinc and increased consumption of crude fiber, potassium, vitamin A, and ascorbic acid. The low dietary intake of zinc by vegetarian women was believed to result from liberal use of foods low in zinc such as fruits and vegetables, whereas vegetarian men primarily consumed zinc-rich food such as legumes and cheeses Lacto-ovo-vegetarians consumed twice the amount of crude fiber consumed by non-vegetarians and vegans four times as much. The zinc content of salivary sediment was significantly lower in vegetarians than in non-vegetarians; vegans had the lowest mean level. The observed decrease in salivary zinc was inversely proportional to the amount of crude fiber in the diet. Zinc levels in the hair of vegetarians were significantly lower than those in the hair of non-vegetarians, while serum levels were also lower, but not significantly so. The increased crude fiber intake of vegetarians coupled with the decreased levels of zinc found in saliva and hair seem to indicate that some vegetarians, particularly women, have less than satisfactory zinc status.

Growth and physiology of potassium-limited chemostat cultures of Paracoccus denitrificans

In potassium-limited chemostat cultures of Paracoccus denitrificans the maximum specific growth rate (µmax) was found to depend on the input potassium concentration: At 0.21mM µmax was 0.10–0.11 h-1; at 0.44 mM 0.15–0.16 h-1 and at 0.66 mM 0.20–0.21 h-1. The plots of the specific rates of oxygen-, succinate-and potassium consumption against μ gave straight lines. The intracellular potassium concentration was a linear function of μ and varied from 1% (0.13 M) at a μ value of 0.034 h-1 to 2.2% (0.29 M) at μ=0.26 h-1; the potassium concentration gradient and the potassium concentration in the culture fluid in the steady state were dependent on the input potassium concentration. The potassium concentration gradient varied from 8,900-1,200. At all μ values 20–25% of the total energy production was used for potassium transport. 350,100 and 30 ATP molecules were calculated to be required to maintain one potassium ion intracellular during 1 h at μ values of 0.034, 0.197 and 0.257 h-1 respectively. It is concluded that the amount of circulation of potassium is dependent on the potassium concentration gradient or on the potassium concentration in the culture in the steady state. The dependency of µmax on the input potassium concentration was explained by the assumption that at low input potassium concentrations the net uptake of potassium (influx-efflux) is not rapidly enough to maintain the high potassium gradient in the existing cells and to establish it in the newly formed cells. At high μ values and at high input potassium concentrations µmax is limited by the specific rate of oxygen consumption, which was found to be 11–12 mmol O2 g dry weight-1 h-1 at µmax for potassium-, succinate-and sulphate-limited chemostat cultures.

Évolution horaire au cours d'une journée normale de la photosynthèse, de la transpiration, de la respiration foliaire et racinaire et de la nutrition N.P.K. chez Zea mays

Abstract Hourly development during a normal day of photosynthesis, transpiration, leaf and root respiration, and of N.P.K nutrition in Zea mays.Metabolism of Zea mays L. cv. INRA F7×F2 can be measured hourly with the “C23A system”, under favourable and constant growth conditions. The photosynthesis is especially stable and is submitted only to a development linked with the leaf surface growth. During the vegetative stage the leaf surface increases regularly both in the day and in the night. The water loss does not change during the diurnal period and remains important during the night if humidity is less than 100%. The leaf respiration is nearly stable. The root respiration, measured with O2 and CO2, fluctuates according to a typical rhythm with two maxima. Day and night mean rates were about the same. The respiratory quotient is about one during the vegetative stage. There is no decrease in the rate of phosphate absorption during the night, and a very small decrease in the rate of nitrate absorption. Ammonium is totally consumed in the first hours after renewal of the nutrient solution. At the same time the potassium consumption is decreased, and then presents a maximum followed by a night reduction. Under our conditions, all of the observations allowed us to assume the presence of an adequate reserve of assimilates and suggest the existence of a precise regulation process, which can ensure an even day night functioning of the plant metabolism, but which does not preclude the presence of internal rhythms, as indicated by the oscillation of the root respiration.

Water use and phosphorus and potassium status of wheat seedlings colonized byGaeumannomyces graminis orPhialophora radicicola

The water consumption and levels of phosphorus, potassium, and total minerals were measured for wheat seedlings colonized byGaeumannomyces graminis var.tritici, Phialophora radicicola var.radicicola, orPhialophora radicicola var.graminicola. Infection byG. graminis resulted in a considerable reduction in water consumption, and reduced level of phosphorus when the supply of phosphorus to the seedlings was plentiful. Colonization byP. radicicola var.radicicola increased levels of phosphorus and potassium, but these increases varied according to the isolate of the fungus and the supply of phosphorus and potassium available to the seedlings. Colonization byP. radicicola var.graminicola resulted in reduced water consumption by the seedlings. The results are discussed in relation to stelar cell wall thickening in wheat roots colonized byP. radicicola, and the effects on nutrient uptake of mycorrhizal root systems.

Nutritional aspects of high-altitude exposure in women

The nutrient intake and urinary excretion characteristics of eight young university women were studied over a 4-day period at low altitude (140 m) and subsequently over a 7-day sojourn on Pikes Peak (4,300 m). High-altitude exposure was associated with a transient decrease in the consumption of protein, carbohydrate, fat, sodium, calcium, phosphorus, vitamin A, riboflavin, thiamin, and niacin and a more sustained decrease in the consumption of potassium and ascorbic acid. In most instances minimal values were observed during the first 3 days of exposure. The carbohydrate fraction of energy intake was increased at the expense of fat during this time period. Individual hypophagic responses appeared to be related to severity of acute mountain sickness. Altitude had no effect on water consumption but did lead to an average body weight loss of 1 kg. Urinary measurements revealed a marked oliguria during the entire sojourn. These measurements also showed the first 3 days to be associated with a net loss of body nitrogen and sodium. During this time period body potassium and phosphorus were conserved, and probably increased. The urea fraction of body potassium and phosphorus were conserved, and probably increased. The urea fraction of total urinary nitrogen was not affected by altitude exposure, nor was the daily excretion of uric acid and creatinine. Ammonia excretion, however, was reduced to 50% of the low-altitude value and remained at this level throughout the sojourn. With a few exceptions, the qualitative characteristics of altitude hypophagia in women were similar to those reported for men. Quantitatively, however, the responses were much more transient in women.

The effect of variations in ability to excrete potassium on potassium ingestion in the rat.

SummaryThe free intake of 5% glucose in 3% KCl (G/KCl) and of other solutions has been compared in rats receiving a normal or a high potassium diet. Consumption of G/KCl was increased in rats on a high potassium diet but consumption of 5% glucose in sodium or calcium chloride solutions, or of potassium or glucose solutions alone, was not increased. Despite an increased potassium ingestion, the plasma potassium concentration was no higher in animals on a high K diet which have an increased ability to excrete potassium, Thus, rats which exhibit potassium tolerance also ingest more potassium when this is offered in solutions with 5% glucose. The reason for this is not established.

EFFICIENCY OF BIOMODIFIZED MINERAL FERTILIZERS APPLICATION FOR BARLEY UNDER DIFFERENT SOIL ACIDITY OF SODDY-PODZOLIC SOIL

The results of the action of mineral fertilizers and bisolbifit biologics on barley on sod-podzolic, heavily loamy soil with different pH values are presented. The use of nitrogen and potash fertilizers in a long-term field experiment on strongly acidic sod-podzolic soil with a mobile aluminum content of 130 mg/kg did not significantly affect the yield of spring barley. The use of the microbial preparation bisolbifit as a fertilizer modifier in these conditions is ineffective. The use of a complete mineral fertilizer in doses of N60P60K60 on calcified soil with a weakly acidic reaction of the soil medium, the yield of spring barley grain reaches 35.3-40.4 c/ha at 19.3 c/ha under control without liming. The introduction of biomodified mineral fertilizers with bisolbifit preparation on this soil leads to an increase in grain yield by 12-14%, reaching 45.4 c / ha. The use of biomodified mineral fertilizers on an optimal background of soil pH increases the payback of 1 kg of NRK by an increase in grain yield by 3.2 kg. The increase in the yield of spring barley grain occurs due to an increase in the number of grains in the ear and the mass of 1000 grains, while the consumption of nitrogen, phosphorus and potassium by plants increases by an average of 9%. The application of a complete mineral fertilizer in combination with a microbial preparation on calcified soil forms a grain with a maximum protein content (12.9%) at a control level of 11.8%.

Effect of o,p′-DDD and metyrapone (SU-4885) on development of renal hypertension in rats

Administration to rats of the compound, o,p′-DDD, an analog of the insecticide DDT, at 1000, 2000, and 3000 ppm in food for 18 weeks protected against both the development of an elevated blood pressure and cardiac hypertrophy which characteristically accompany bilateral encapsulation of the kidneys with latex envelopes. Administration of the highest dose was accompanied by the lowest blood pressure. The compound was not toxic at the doses used as defined by normal food and fluid intake and growth rate. Rate of oxygen consumption and serum concentrations of sodium, potassium, and chloride were also unaffected by o,p′-DDD at 1000 or 2000 ppm in the diet. Metyrapone (SU-4885), administered at 1000 and 2000 ppm in the diet, decreased growth rate and failed to protect againts the development of renal hypertension in rats.

Active transport of potassium and oxygen consumption in the isolated midgut of Hyalophora cecropia.

ABSTRACT Flux measurements with 42K reveal that in the isolated midgut of Hyalophora cecropia 90 to 100 % of the short-circuit current is carried by the active transport of potassium from the blood-side to the lumen. When K-transport is strongly depressed, either by withholding potassium from the blood side or by imposing a large positive potential on the lumen, the oxygen uptake of the isolated gut remains virtually unchanged. If the K-transport were to be energized by the negligible increase in oxygen uptake about 40 μ-equiv. of potassium would have to be transported for every μ-equiv. of extra oxygen taken up. This ratio of K-transport to oxygen uptake is thermodynamically impossible. The ratio of potassium transported to total oxygen consumed when the midgut is bathed with 32 mM potassium on both sides is about 1·3 at temperatures of 25° and 15° C. The ratio must be smaller at lower potassium concentrations and is 2·0 at 73·5 mM-K, which may be approaching the maximum value. Although the oxygen uptake is independent of the K-transport, the reverse is not true. There is a close dependency of K-transport on oxygen consumption. K-transport by the midgut contrasts with Na-transport by the frog skin because Na-transport stimulates oxidative metabolism whereas K-transport does not. Evidently the coupling of transport to energy supply is different in the two systems.

Single vs. Split Potassium Applications for Coastal Bermudagrass1

SynopsisSplitting annual potash applications increased hay yields of Coastal bermudagrass only as available potassium in the soil reached a very low level. Splitting potash applications, however, consistently increased available potassium in the soil over single applications. Luxury consumption of potassium can be reduced by making split applications of potash at no more than half the nitrogen rates on soils kept low in available potassium.

Oxygen consumption of the hypothermic potassium arrested heart.

SummaryOxygen consumption of the potassium arrested heart averaged 2.1 ml/min/100 g of perfused heart at normal body temperature, and 0.66 ml/min/100 g of perfused heart at 21.5 to 25°C.

RELEASE OF POTASSIUM BY 18 ONTARIO SOILS DURING CONTINUOUS CROPPING IN THE GREENHOUSE

Eighteen Ontario soils were ranked according to their capacity to supply potassium from non-exchangeable forms to eight successive crops of alfalfa. This capacity was found to be closely related to the percentage of clay in the soils. Potassium content of the alfalfa and total uptake of potassium were highly correlated with both exchangeable soil potassium and release of potassium from non-exchangeable forms. Exchangeable potassium levels below 100 lb. per acre gave low yields and potassium content of the crop. Excessively high exchangeable potassium levels resulted in luxury consumption of potassium by the crop or in fixation by the soil. In soils at or near their equilibrium exchangeable potassium levels, i.e., not heavily fertilized, there was a close relationship between potassium-supplying power and the exchangeable potassium content measured either before cropping commenced or at the end of the cropping period.

Effect of Rainfall and Fertilization on the Yield and Chemical Composition of Alfalfa over a 10‐Year Period in North Central Oklahoma

AbstractClimatic environment had a greater influence than soil treatment on the quantity of nitrogen, calcium, potassium, magnesium, and phosphorus in 26 cuttings of alfalfa hay grown on the Oklahoma Agricultural Experiment Station, Perkins Farm, from 1937 to 1946. The protein content of the first cutting of alfalfa was equal to, or higher than, the protein content of the second or third cuttings of hay in 8 out of 9 years. The calcium content of the hay was usually high when soil moisture was low, and low when soil moisture was high during the growing period. The minimum and maximum percent of calcium in different cuttings varied nearly 100%. The potassium and phosphorus content of different alfalfa cuttings varied more than 100%. A luxury potassium consumption by alfalfa occurred on this soil. Lower phosphorus percentages usually were observed in the alfalfa hay when rainfall was low for several weeks before the crop was cut. Factors which increased or decreased the quantity of phosphorus obtained by the alfalfa plants from the natural phosphates in the soil had a similar influence on the uptake of applied phosphates. The average absorption of phosphorus from rock phosphate by alfalfa was similar to the quantity of phosphorus obtained from superphosphate on unlimed soil, but was slightly lower on the limed plots. A greater variation occurred in the nitrogen and phosphorus content of the stems than in the leaves of mature alfalfa plants grown on variously treated plots.

Luxury Consumption of Potassium by Plants and Its Significance1

Analyses were made to determine the potassium content of grown in soil, sand, and solution cultures which had received applications of different amounts of potassium. A theory for the utilization of potassium is developed from the data presented. The application of the theory to fertilizer practices is discussed. The results may be summarized as follows: 1. Plants absorb considerable more potassium during the early periods of growth than is necessary for the normal processes of growth. This applied to the crops studied, including alfalfa, Hubam clover, cowpeas, soybeans, oats, wheat, Sudan grass, corn, cotton, and tomatoes. 2. The potassium in the tomato plant is practically all water soluble. 3. Potassium can be translocated within the plant and reutilized to prevent starvation when the supply of available potassium is insufficient to supply the needs of the growing regions. 4. It is suggested that the luxury consumption of potassium followed by translocation and reutilization of the potassium in the plant is an important process in the assimilation of potassium by plants.