Participação da excreção renal de cálcio, fósforo, sódio e potássio na homeostase em cães sadios e cães com doença renal crônica / Participation of renal excretion of calcium, phosphorus, sodium and potassium on the homeostasis in healthy dogs and in dogs with chronic kidney disease

In chronic kidney disease (CKD), the first problem to be solved by the organism is to maintain water and sodium homeostasis and, with the worsening of the renal injuries, other severe problems related to the calcium and phosphorus homeostasis emerge. The present study has the purpose to evaluate the renal excretion and serum profile of calcium, phosphorus, sodium and potassium in healthy dogs and in dogs with naturally acquired CKD. Three groups of adult male and female dogs of varied breeds were evaluated. Normal dogs were in the control group (G1) and the CKD dogs were distributed into two groups in accordance with the stage of renal function impairment (G2 e G3, respectively, stages 1-2 and stages 3-4, proposed by IRIS 2006 staging CKD). The G3 dogs showed increased serum levels of ionized calcium and phosphorus, in addition to the reduction of sodium levels. Regarding the renal excretion of the analyzed electrolytes, the G1 and G2 groups showed a decrease of filtered load and increase of fractional excretion, yet there were no significant variations on the urinary excretions. The results suggest that the kidneys of the CKD dogs can maintain similar values of electrolytes urinary excretion as the kidneys of normal dogs. The mechanism involves an increase of fractional excretion while glomerular filtration decreases. This compensation process, however, can lose its efficiency in the later stages of the disease, in relation to the maintenance of phosphorus and sodium serum levels.

Na doença renal crônica (DRC) a manutenção da homeostase de água e sódio é o primeiro problema a ser contornado pelo organismo e com o agravamento das lesões renais surgem outros problemas graves relacionados à homeostase de cálcio e fósforo. O presente estudo tem por escopo avaliar a excreção renal de cálcio, fósforo, sódio e potássio, e o perfil sérico destes eletrólitos em cães normais e em cães com DRC naturalmente adquirida. Foram avaliados três grupos de cães adultos, machos ou fêmeas, de raças variadas. Animais normais compuseram o grupo controle (G1) e os cães com DRC foram distribuídos em dois grupos de acordo com os estágios de comprometimento da função renal (G2 e G3, respectivamente, estágios 1-2 e estágios 3-4, descritos pela IRIS 2006 staging CKD). Os cães do G3 apresentaram aumento das concentrações séricas de cálcio ionizado e fósforo, além de diminuição da concentração sérica de sódio. Quanto à excreção renal dos eletrólitos analisados, os animais dos grupos G1 e G2 apresentaram diminuição de carga filtrada e aumento de excreção fracionada, mas as excreções urinárias não variaram significativamente. Os resultados são indicativos de que os rins de cães com DRC podem manter a excreção urinária dos eletrólitos em valores se melhantes aos dos normais. O mecanismo envolve aumento da excreção fracionada na medida em que haja diminuição da filtração glomerular. Esse processo de compensação, entretanto, pode perder a eficiência nos estágios mais avançados da enfermidade no que se refere à manutenção das concentrações séricas de fósforo e sódio.

Diuretic effect of powdered Cerasus avium [cherry] tails on healthy volunteers

In this study, the diuretic activity of powdered cherry stalk was evaluated in 13 healthy volunteers by means of their water balance. In addition to biochemical parameters, such as urinary electrolyte concentration, osmolality and any adverse reaction were determined. The capsules of cherry stalks were administered at an equivalent dose of 2.0 grams of the plant per person. Urinary biochemical determination was made of concentration of electrolytes [sodium, potassium, chloride and calcium], urinary volume and osmolality by standard laboratory procedures. Statistical evaluation was performed by Student's-t and Wilcoxon rank tests. After administration of cherry stalk, the mean of urine calcium, sodium, chloride, and urine volume increased, but the amount of urine potassium and urine osmolality did not change. No adverse reaction was observed. Powdered C. avium stalk increased mild urine volume confirming thus the claimed diuretic effect of the herb. Administration of cherry stalk caused urinary sodium and chloride rising less than loop diuretics but higher than the others. Because of rising calcium excretion, it should be used with cautious in those with urolithiasis

Urinary sodium and potassium excretion following karate competitions

Exercise induces renal hemodynamic alterations and stimulates electrolytes excretion. The purpose of this study was to assess urinary excretion of sodium and potassium in karate practitioners, following competitions. The study population composed of 18 healthy men, aged 18 to 21 years, with similar physical characteristics. They were professional karatekas with a history of at least 7 years of karate training. The participants competed in 3 rounds of about 3 minutes in duration with 10 minutes resting intervals between them. The 24-hour urine samples were collected before [while trainings were stopped] and after the match and their sodium and potassium concentrations were measured. Also, blood samples were obtained before and after the match for measurement of these electrolytes in the participants' sera. Before the match, the mean values of urinary sodium and potassium were 200.3 +/- 89.3 mEq/L/d and 68.5 +/- 12.9 mEq/L/d, respectively. After the match, they changed into 206.9 +/- 74.7 mEq/L/d and 67.1 +/- 14.4 mEq/L/d, respectively. No significant alterations were observed in urinary sodium and potassium excretion following karate match [P = .94 and P = .96, respectively]. Serum sodium levels were 136.7 +/- 3.1 mEq/L and 136.3 +/- 2.9 mEq/L, before and after the match, respectively [P = .11], serum potassium levels were 4.2 +/- 0.3 mEq/L and 4.1 +/- 0.2 mEq/L, respectively [P = .16]. With regard to short duration and anaerobic nature of karate, it seems that a Karate match does not contribute to excessive urinary electrolytes excretion

Corpus of biochemical changes after death by potassium intoxication in rabbits / 法医学杂志

OBJECTIVE@#To explore the objective evidence of the corpus biochemical changes in rabbits for postmortem diagnosis of potassium intoxication.@*METHODS@#Rabbits were sacrificed by Infusion of 0.3% KCl at full speed push or 1% KCl at 100 drip/min, respectively, with normal rabbits used as control. Cardiac blood and urine samples were collected before and after potassium infusion to examine the concentrations of various electrolytes (K+, Na+, Ca2+, Mg2+, Cl-, and HCO3-) and to observe the antemortem and postmortem biochemical changes.@*RESULTS@#The mean lethal infusion time in the 0.3%KCl group was longer than that in the 1% KCl group (P = 0.006). The serum concentration of K+ increased while the serum concentrations of Na+, Ca2+, Cl-, and HCO3- decreased after the infusion. There were no statistically significant differences in the whole blood concentration of K+ as well as the serum concentration of Mg2+ between the two groups (P = 0.062). There were statistically significant differences in the concentrations of whole blood K+, as well as serum Na+, Mg2+, and Cl-, but not in the serum K+, Ca2+, and HCO3-. There were no statistically significant differences seen in the urine volumes and the concentrations of all the urine electrolytes between the groups.@*CONCLUSION@#Examination of the concentrations of K+ both in the whole blood and serum, as well as Mg2+ in the serum may be helpful for postmortem diagnosis of potassium intoxication.

Effect of nitrendipine, nimodipine and nisoldipine on water and electrolytes excretion in rats.

In water loaded (5 ml/100 g) unanesthetized rats. nitrendipine (NT), nimodipine (NM) and nisoldipine (NS) (5 mg/ kg, i.p.) caused significant (P < 0.01) increase in water and Na+ excretion. However, there was no significant increase in K+ excretion after NT, NM and NS administration. NS was more potent in increasing excretion of water load as compared to NT and NM. The glomerular filtration rate as assessed by creatinine clearance, was significantly (P < 0.01) increased in NT, NM and NS (5 mg/kg, i.p.) treated groups as compared to control. The mean creatinine clearance values after NT, NM and NS were 26.95 +/- 0.35, 22.11 +/- 0.72 and 28.13 +/- 0.95 respectively as compared to 22.19 +/- 0.51, 18.77 +/- 0.42 and 22.97 +/- 0.60 in corresponding control groups. The results of the study suggest that in addition to other effects, NT, NM and NS have a selective inhibitory effect on Na+ handling mechanisms in the nephron.

Evaluation of Ammannia baccifera Linn. for antiurolithic activity in albino rats.

Ethanolic extract of A. baccifera was tested for its antiurolithic activity in male albino rats. Urinary stones were induced by implantation of zinc discs in the urinary bladder. The stones formed were mainly of magnesium ammonium phosphate with traces of calcium oxalate. Ethanolic extract of A. baccifera (2g/kg/day, po) was found to be effective in reducing the formation of stones as also in dissolving the pre-formed ones. There was a significant increase in the urinary excretion of calcium, magnesium and oxalate, four weeks after implantation of zinc discs. Treatment with A. baccifera has significantly reduced calcium and magnesium levels in the prophylactic group while it has reversed the levels of these ions to normal values in the curative group.

Evolución de los electrolitos séricos durante el tratamiento de rehidratación de pacientes con diarrea aguda coleriforme / Serum electrolytes during the rehydration treatments of patients with acute cholera diarrhea

Objetivo: evaluar los niveles séricos de sodio, potasio, cloro y reserva alcalina de pacientes oligúricos con deshidratación moderada o severa por diarrea coleriforme al momento de la admisión, al recuperar diuresis luego de rehidratación con ClNa 0.9 por ciento EV y al alta hospitalaria cuando la rehidratación fue continuada con sales de rehidratación oral y solución polielectrolítica EV en unos y sales de rehidratación oral y ClNa 0.9 por ciento EV en otros. Resultados: el volumen de ClNa EV necesario para restablecer el flujo urinario fue de 4.2 +/- 1.2 litros y fue conseguido en 1.8 +/- 0.7 horas. Al momento de la admisión, los valores séricos de Na fueron 135 +/- 5 mEq/L, el K 4.5 +/- 0.7 mEq/L, el cloro 100 +/- 8 mEq/L y la reserva alcalina 23.7 +/- 9.2 mEq/L. Al momento de recuperar la micción solo se apreciaron cambios significativos en la reserva alcalina la que fue encontrada en 28.7 +/- 7.1 mEq/L. Ninguno de los otros electroliticos tuvieron alteraciones significativas. Este patron persistio hasta el momento del alta de los pacientes. No hubo diferencia significativa en los valores bioquimicos finales ni en el curso clínico de los pacientes tratados unicamente con ClNa 0.9 por ciento EV y sales de rehidratación oral y aquellos tratados con ClNa, solución polielectrolítica endovenosa y sales de rehidratación oral

Effect of dietary salt (NaCl) supplementation on urinary profile of guinea pigs (Cavia porcellus).

Sodium chloride supplementation (120 mg/kg of body weight/day) for 12 days increased the urinary excretion of calcium from 91.6 +/- 9.0 to 159.4 +/- 16.0 mumol/day and of sulphate from 266.8 +/- 24.5 to 1176.9 +/- 87.2 mumol/day in guinea pigs. The stone risk due to increased urinary calcium excretion could possibly be counterbalanced by increasing urinary sulphate excretion. High salt intake, thus, could not increase the risk of stone formation.

hydro electrolytic disorders in the primary hypothyroidism

This study reports the hydroelectrolytic disorders observed in 14 cases of primary hypothyroidism. Their exploration involves a water-loading test, an hydromineral and hormonal evaluation, the latter includes thyroid and adrenocortical functions, neurophysin ll and ADH levels. This explorations allows the authors to discuss some pathogenic mechanisms: hypervasopresinism, renal, thyroid and adrenal insufficiency. The results show, at patients affected with hypothyroidism, a plasma hypoosmolality, an hyponatremia, and urinary hyperosomlality and an impaired water excretion. Our findigns are in agreement with those observed in the medical litterature. The renal factors seem in part involved in the genesis of these perturbations

Urinary constituents in an endemic area of stones and renal tubular acidosis in northeastern Thailand.

Nephrolithiasis and endemic renal distal tubular acidosis are common in northeastern Thailand. The etiology is still unknown. It is generally accepted that urine electrolytes influence the capacity of urine to inhibit or promote renal and also bladder stones. The purpose of this study was to analyse the composition of the urine in the indigenous population in the northeast area and compare their values with data obtained from a group of age matched adults, living in Bangkok. Twenty-four hour urine samples from 23 normal adult villagers from six villages within the province of Khon Kaen and 34 normal adults living in Bangkok were collected, and the daily excretion of creatinine, uric acid, calcium and inorganic phosphate, sodium, potassium, chloride, magnesium and oxalate were assayed. Daily urinary sodium, potassium, chloride and phosphate of the villagers were significantly lower than those of Bangkokians. No difference in the urinary excretion of calcium, magnesium, uric acid, oxalate and creatinine was found. The Na/Ca, and Ca/PO4 ratios of villagers were significantly lower than those of the Bangkok subjects. The villagers excreted significantly lower amounts of Na in the face of relatively higher urinary Ca. The above data, combined with our previous study showing the low values of urinary citrate in the villagers in the same areas, strongly indicate that the indigeneous population is at high risk in developing urolithiasis. The causes for these electrolyte abnormalities are still unknown. Low contents of the major electrolytes in their diets might play an important role. Low phosphate output indicates low protein diets.(ABSTRACT TRUNCATED AT 250 WORDS)

Biochemical mechanisms and effects of Mimosa pudica (Linn) on experimental urolithiasis in rats.

Urolithiasis, following implantation of Zn discs in urinary bladder (foreign body insertion technique), was examined in albino rats of either sex. Marked variation was observed between sex, regarding the formation of bladder stones. Ethylene glycol (1%) mixed in drinking water for 4 weeks, was unable to augment Zn disc-induced stone deposition. Chemical nature of stones was identified as of magnesium ammonium phosphate type. Neither urinary pH nor infection in the urinary bladder/tract affected chemical nature and quantity of stone formed. There was no significant influence of electrolytes or metabolic products on the uroliths. No correlation could be drawn between the quality and quantity of uroliths formed and the urinary electrolytes concentration. M. Pudica was not effective in either preventing stone deposition or dissolving preformed stones.

Acute effects of neurogenic stress on urinary electrolyte excretion.

Plasma Cortisol and urinary excretion of water, sodium, potassium, calcium and magnesium have been studied in the rat after application of 2 types of neurogenic stress:--(a) tight rubber band tourniquet and (b) electric shock. Plasma cortisol levels increased significantly after application of either type of stress. During both type of stress, there was statistically significant increase in the urinary excretion of water, sodium and calcium but not of potassium and magnesium. Urinary calcium/magnesium ratio was also significantly elevated. The results suggest that stress may be one of the factors involved in the genesis of urolithiasis.

Studies on Electrolytes and Nitrogen Metabolism of the Korean

In order to further characterize the basic pattern of electrolyte and nitrogen metabolism of the Korean, 24-hour urines were collected from 1,260 male subjects who were randomly selected from three different geographical areas (city, rural and island) in age from 6 to 25. For the city subjects, studies were conducted in both summer and winter for a seasonal comparison, while the other subjects were studied in the autumn only. Of these subjects, blood samples were also obtained from 225. In all groups, the serum composition of electrolytes including proteins was within normal range. The daily urine output which increased as a function of age was somewhat greater in summer than in winter. The daily urine output per unit surface is decreased inversely according to age. On the other hand, the urine osmolality which increased with age was higher in winter than in summer. The daily salt excretion which was greater in summer than in winter increased according to age, although the daily salt excretion per unit surface area was constant regardless of age. The daily potassium excretion was such that the urinary K/Na ratio decreased according to age while it was higher in winter than in summer. Likewise, the daily nitrogen excretion was much greater in winter than in summer while it increased with age. However, the daily nitrogen excretion per unit surface area decreased in older subjects age. In contrast to these seasonal differences in respect to certain electrolytes and nitrogen excretion, there was no distinct geographic difference in these variables. Moreover, many of the above variables changed according to age, but tended to stabilize at the age of approximately 15 years. A comparison of the present data with others indicates that the daily urine output and the daily salt excretion are greater while the urine osmolality, the daily nitrogen excretion and the urinary K/Na ratio are lower in the Korean than in the occidental. Moreover, these results strongly suggest that Korean people acquired a habit of ingesting low-protein and high-salt diets at the age of 6 years or perhaps before.