Randomized Clinical Study, Comparative of Parallel Groups, to Evaluate the Effectiveness of Three Preparations of Potassium Citrate in Producing an Increase in Urinary pH in Patients with a History of Kidney Stones

Background: A very strict control of urinary pH is recommended to maintain it between 5.5 and 6.2, preventing formation or recurrence of crystals. Kidney stones are a common problem, with a high rate of recurrence, not altered by the success of surgery. Medical treatment prevents recurrence. Potassium Citrate inhibits crystallization of calcium salts. It influences calculogenesis by increasing urinary citrates and alkalinizing the urine. Purpose: to evaluate the similarity in the effect of three K citrate products, K citrate reference product Urocit®10 mEq, and K citrate from Laboratorios LETI S.A.V., 10 mEq and 15 mEq, on urinary pH. Materials and Methods: We carried out a prospective, randomized study of three parallel groups. We admitted female and male patients with history of kidney stones or evidence of lithiasis (grit, microlithiasis) in the renal echosonogram. Laboratory assessments: urine, 24-hour urine, urinary pH, Calcium, uric acid, Phosphorus, Sodium, protein and urinary creatinine at times: start, day 7, day 21, 30 of treatment. Results: all three products produced a slight increase in urinary pH in the simple urine test and 24-hour urine, with no differences between groups or their logarithmically transformed means and their CI95, which did not exceed the range between 80% and 125%. Conclusions: K Citrate, 10 mEq and 7.5 mEq, from Laboratorios LETI, S.A.V., at a dose of 30 mEq daily in patients with history of kidney stones are equivalent to the reference product Urocit®, in its effects on urinary pH in 24-hour urine, and in the simple urine test.

Reducing Dietary Cation-Anion Difference on Acid-Base Balance, Plasma Minerals Level and Anti-Oxidative Stress of Female Goats

Reducing dietary cation-anion difference （DCAD） has been proved an effective way to prevent milk fever in dairy cows. Based on the similar physiological gastro-intestinal tract anatomy and metabolic process between female goats and dairy cows, this study was conducted to evaluate the effects of varying DCAD on fluid acid-base status, plasma minerals concentration and anti-oxidative stress capacity of female goats. Urinary pH, plasma Ca, P and Mg; and anti-oxidative stress indices of total superoxide dismutase （T-SOD）, hydrogen peroxide （HzO2）, glutathione peroxidase （GSH-Px） and malondialdehyde （MDA） were determined to evaluate the effect. Forty-eight Guizhou black female goats （（15±1.9） mon of old, （22.3±3.75） kg of BW） were randomly allocated to 4 blocks of 12 goats each and were fed 1 of 4 diets differed in DCAD level （calculated as Na＋K-C1-S, mEq kg-1 DM）. Levels of DCAD were preliminarily designed to be control （＋ 150 mEq kg^-1 DM, CON）, high DCAD （＋300 mEq kg^-1 DM, HD）, low DCAD （0 mEq kg^-1 DM, LD） and negative DCAD （-150 mEq kg^-1 DM, ND）, respectively. A commercial anionic salts （Animate） and sodium bicarbonate （NaHCO3） were supplemented to reduce and increase DCAD level, respectively. There was no difference in dry matter intake for 4 groups of goats. Urine pH was aggressively decreased （P〈0.0001） with reduced DCAD and there was a strong association between DCAD and urine pH （R2=0.793, P〈0.0001）. Compared with CON and HD feeding of LD and ND resulted in greater （P〈0.05） plasma Ca concentration. Plasma P level was increased （P〈0.05） when anionic salts were supplemented. The DCAD alteration did not affected （P〉0.05） plasma Mg level. There was no significant （P〉0.05） difference in plasma GSH-Px activity and H202, but anionic salts supplementation in LD and ND significantly increased （P〈0.05） plasma T-SOD activity and tended to reduce MDA （P〈0.1） over HD and CON. Results from this study indicated that reducing DCAD could decrease urine pH and increase plasma Ca concentration of female goats. Additionally, reducing DCAD was helpful to enhance anti-oxidative stress capability of female goats.

Evaluation of the diuretic effects of crude stem bark extraction of Zanthoxylum heitzii(Rutaceae) in Wistar rats

OBJECTIVE： Zanthoxylum heitzii is a medicinal plant widely used in central Africa for the treatment of many diseases, especially cardiovascular diseases and hypertension. The diuretic effects of crude stern bark extraction were determined and its safety in rats was evaluated. METHODS： The diuretic effects of crude stem bark extraction of Z. heitzii were investigated in Wistar rats （250 g ＋ 10 g） of both sexes. The crude stem bark extraction of Z. heitzii at the doses of 225, 300 and 375 mg/kg was administered to rats at 5 mL/kg body weight. Urine volume was determined 1, 2, 3, 4, 5, 6 and 24 h after administration of the extract. Kinetics of electrolyte elimination in response to a single oral administration dose of acute treatment was measured. The experiments were performed under the same conditions with two synthetic pharmacological diuretics considered as reference （furosemide and hydrochlorothiazide）. Urinary and plasma concentrations of sodium and potassium ions were determined using flame photometry. Concentrations of creatinine, urea, glucose, albumin and electrolytes in the plasma and urine samples were evaluated using a two-way digital bidirectional spectrophotometer. The osmolarity of plasma and urine samples was measured by cytometry using an osmometer. Aldosterone was measured by radioimmunoassay. RESULTS： The plant extract accelerated the elimination of overloaded fluid and increased urine volume and the excretion of Na＋, K＋ and CI 24 h after administration （P〈0.05）. The increase in elimination of Na＋, K＋, and Cl- induced by the extract caused alkalinization of the urine, and showed a strong inhibitory effect on carbonic anhydrase and saluretic. These effects were mainly observed at the dose of 375 mg/kg. At the maximum diuretic response, urinary osmolarity decreased significantly （P 〈 0.05） when compared to controls. The stability of aldosterone level, the absence of correlation with the plasma levels of Na＋, and increased clearance of free water in the animals treated with extract indicated that increased diuresis and natriuresis were tubular in origin. No significant （P 〉 0.05） changes were observed in the body temperature of the animals. CONCLUSION： The significant increase in urine volume 24 h after treatment followed a doseresponse pattern. The excretion of Na＋, K＋ and Cl- caused a decrease in urine osmolarity. The stability of aldosterone, the absence of correlation with the plasma levels of sodium, and increased clearanceof free water in animals treated with aqueous extract suggest that increased diuresis and moderate natriuresis elevation were of tubular origin.