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1.
Aminoglycoside nephrotoxicosis (AGNT) was induced in ewes by daily SC administration of gentamicin. Changes in urinary indices of renal function during the development of AGNT are reported. Measurements from timed, volume-measured urine samples were made on days 0, 7, and 8 and included creatinine clearance, total excretion (TE) rates of electrolytes (Na, K, Cl, P) and urine volume. Measurements from free-catch urine samples (without volume measurement) were made daily and included fractional excretion (FE) rate of electrolytes, urine osmolality, and urine-to-serum osmolality and urine-to-serum creatinine ratios. With the onset of AGNT, FE rates of Na, K, Cl, and P- increased many fold above baseline values (200x, 4 to 5x, 6 to 9x, and 70 to 95x, respectively, on days 7 and 8), indicating decreased tubular reabsorption or increased tubular secretion. The increased FE rates were not representative of increases in total electrolyte excretion rates. The total excretion of Na (TENa) was mildly increased, TEK was decreased, TECl was unchanged, and TEP was significantly increased on days 7 and 8. Abnormal urinalysis results, glucosuria, and increased FEP preceded appreciable increase in serum creatinine concentration. Other abnormal urinary indices of renal function coincided with or followed the increase in serum creatinine concentration. Urinary indices may help characterize renal function associated with the disease state, but did not provide early indication of AGNT.  相似文献   

2.
Data of 50 balance measurements were collected from dry and lactating Holstein cows to clarify the effects of urinary excretion of nitrogen (N), potassium (K) and sodium (Na) on urine volume in cows. In dry cows, orchardgrass silage, timothy hay, alfalfa silage and corn silage were offered to meet the TDN requirement. Orchardgrass silage or alfalfa silage diets were offered in switch back trials in lactating cows. There were no relationships between urinary excretion and plasma concentrations of K or Na in cows, but urinary N excretion increased with the increase of plasma urea nitrogen. There was positive correlation between urinary excretion and urinary content of Na, but urinary K contents increased rapidly by 1.3% with the increasing urinary K excretion and thereafter remained almost constant. The increasing urinary K and N excretion enhanced urine volume in cows, but urine production in cows was accurately estimated from the regression equation of urine K excretion on urine volume. Urine volume was not affected by urinary Na excretion. These results suggest that the increase of urine volume in cows affected by the increasing urinary excretion of K and N may be due to the maintenance of urine or plasma osmolality.  相似文献   

3.
Cisplatin (90 mg/m2) was administered in a 5-minute bolus IV infusion to dogs at 8 AM (n = 6) or 4 PM (n = 6). Blood and urine samples were collected over a 4-hour period for statistical moment pharmacokinetic analysis. Mean urinary excretion rate of total platinum was increased, whereas mean plasma residence time of ultrafilterable platinum was decreased, in the group treated at 4 PM (PM group), compared with those treated at 8 AM (AM group). Over a 2-week postinfusion-monitoring period, both groups of dogs developed decreases in creatinine clearance, urine/serum osmolality ratio (UOsm/SOsm), specific gravity, and increase in BUN, serum creatinine concentration, urine gamma-glutamyltranspeptidase/urine creatinine ratio (UGGT/UCr), fractional excretion of magnesium, and fractional excretion of phosphate. Urine specific gravity and UOsm/SOsm were significantly decreased, whereas UGGT/UCr and BUN were significantly increased in the AM group, compared with the PM group. The time of administration had a significant effect on the pharmacokinetics of cisplatin, which resulted in significant differences in cisplatin-induced renal toxicosis.  相似文献   

4.
Gentamicin concentrations in serum, urine and milk were assayed microbiologically after intramuscular and intrauterine administrations in normal and endometritic cows. Following intramuscular injections of 5 mg gentamicin/kg b. wt. 3 times daily for three consecutive days, the highest serum concentrations occurred 1 h post administration of each dose with absorption half-lives [t0.5(ab)] ranging from 0.23 to 0.30 h for normal cows and from 0.21 to 0.29 h for endometritic cows. The elimination half-lives [t0.5(beta)] ranged from 2.51 to 2.95 h (normal cows) and from 2.71 to 3.29 h (endometritic cows). Following intrauterine administration of 4 mg gentamicin/kg. b. wt. once daily for three consecutive days, the drug peaked in serum 2 h after each dose with [t0.5(ab)] ranging from 0.47 to 0.52 h (normal cows) and from 0.57 to 0.68 h (diseased cows), while the drug was eliminated faster in endometritic cows than in normal cows. The mean systemic bioavailability were (70%) and (30%) after intramuscular and intrauterine administration, respectively. To compare serum concentrations, gentamicin was assayed in urine and milk in high and low concentrations, respectively.  相似文献   

5.
The aminoglycoside gentamicin is often used in equine practice. Despite its clinical use, concerns remain regarding the potential toxic side-effects, such as nephrotoxicity, in equine patients, particularly after repeated dosing. The aim of the study was to investigate first in vitro the mechanisms contributing to the renal toxicity of gentamicin and to identify sensitive biomarkers indicating proximal tubule damage. To this end, the kidney-derived cell lines LLC-PKI and MDCK were treated with gentamicin at different concentrations. Toxicity was assessed by measuring the release of gamma-glutamyl transferase (GGT), and the production of reactive oxygen species (ROS). Cell viability was measured using Alamar blue (AB) and Neutral red (NR) cytotoxicity assays. Gentamicin exerted a dose-dependent toxicity. Primarily, loss of brush border membrane integrity, indicated by GGT leakage, and an increased ROS production were observed. As GGT was found to be a sensitive marker for gentamicin-induced renal cell injury, in the subsequent in vivo experiments, in which ponies were given gentamicin (3.0 mg/kg bw three times daily and 4.5 mg/kg bw twice daily) for five consecutive days, plasma levels and the urinary excretion of GGT and creatinine were measured and the GGT:creatinine ratio was calculated. Elevated GGT levels in urine following gentamicin therapy were observed, but this enzyme leakage was transient and returned to baseline values after cessation of therapy. It could thus be concluded that even a conservative dose regimen of gentamicin did not result in significant renal toxicity in healthy ponies.  相似文献   

6.
Acidemia stimulates renal ammonia production and excretion. This adaptive response allows increased H+ secretion and generation of new bicarbonate. To determine whether a relationship existed between urine ammonium (NH4+) concentration and excretion and urine anion gap (Na+ + K(+)- Cl-), ammonium chloride (NH4Cl) was administered per OS for 5 days to induce systemic acidemia in 12 healthy Beagles. During NH4Cl administration, a strong, statistically significant (P less than 0.0001) relationship was apparent between urine NH4+ concentration measured in millimoles per liter and urine anion gap. Regression equation: urine [NH4+] = 8.2 - 0.416 x urine anion gap; r = -0.897. A statistically significant (P = 0.0001) relationship existed between urine NH4+ excretion measured in millimoles per kilogram of body weight per day and urine anion gap. Regression equation: urine NH4+ excretion = 0.74 - 0.38 x urine anion gap; r = -0.768. As urine NH4+ concentration or excretion increased, urine anion gap became more negative. Before NH4Cl administration (no systemic acidemia), a weak, but statistically significant (P = 0.015) relationship was observed between urine NH4+ concentration and urine anion gap. Regression equation: urine [NH4+] = 65.2 - 0.141 x urine anion gap; r = -0.41. However, a relationship was not evident between urine NH4+ excretion and urine anion gap before NH4Cl administration. Hence, urine anion gap is a reliable index of urine NH4+ concentration and excretion only in dogs with metabolic acidosis. In human beings with distal renal tubular acidosis, NH4+ excretion is inappropriately low and results in a positive urine anion gap.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

7.
Alterations of acid-base status, and fluid and electrolyte balance subsequent to exercise in Thoroughbred racehorses in North America have not been well-characterized. Des-cribed here are the results of an observational study conducted to characterize changes in fluid and electrolytes following strenuous exercise of 16 Thoroughbreds under routine training conditions. Changes following strenuous exercise were determined for the following variables: serum concentrations of sodium (Na), potassium (K), chloride (Cl) and protein; pH of blood; osmolality of plasma and urine; body weight; and, fractional urinary excretion (FE) of Na, K and Cl. The following changes occurred during exercise: increased concentration of Na in blood; increased FE of Na; decreased concentration of Cl in blood; decreased FE of Cl; increased urinary and plasmal osmolality; weight-loss; decreased pH of blood; and, increased concentration of lactic acid. The concurrent decreased concentration of chloride in plasma and acidemia in these horses differed from the hypochloremic, metabolic alkalosis previously described among endurance horses. Acidemia was attributed to production of lactic acid by anaerobic glycolysis.  相似文献   

8.
SUMMARY: To determine whether administration of glycerol-containing solutions induces a state of transient hyperhydration in resting euhydrated horses, changes in plasma and urine constituents were measured in four horses for 1 h before and 5 h after nasogastric administration of each of four treatments (Experiment 1). Treatments were applied in a randomized fashion and included: (1) 1.0 g.kg(-)(1)glycerol in 8 L of water (G); (2) 8 L of water (W); (3) 8 L of 0.9% NaCl solution (S); and (4) 1.0 g.kg(-)(1)glycerol in 8 L of 0.9% NaCl solution (GS). In a subsequent study, voluntary water intake was measured hourly for 5 h after nasogastric administration of each treatment (Experiment 2). All treatments produced mild plasma volume expansion ranging from 3.2 to 5.8% in Experiment 1. Administration of glycerol containing solutions increased serum glycerol concentration approximately 100-fold and plasma osmolality (P(osm)) by approximately 10 mOsm/kg and resulted in a tendency towards increased renal water conservation despite increased osmole excretion. In contrast, W treatment decreased plasma and urine osmolality and was accompanied by increased urine production and decreased renal water conservation. Plasma and urine osmolality, as well as renal osmole and water excretion, were unchanged after S administration. In Experiment 2, horses treated with GS voluntarily drank an additional 5.2 +/- 0.9 L of water during the initial hour following nasogastric administration of 8 L of solution. Voluntary water intake with the other treatments was less than 1.0 L for the entire 5 h observation period. Collectively, the results of both experiments suggest that administration of glycerol in saline would produce transient hyperhydration in resting euhydrated horses by enhancing renal water conservation and stimulating voluntary water intake.  相似文献   

9.
The purpose of this study was to assess the effects of dietary salt intake on systolic blood pressure, water intake, urine output, and urine concentration in cats. Ten healthy young adult cats (mean age 2.5 years) were randomly divided into 2 groups and fed either a control diet (0.46% Na and 1.33% Cl on a dry matter [DM] basis) or a diet with a moderately increased salt content (1.02% Na and 2.02% Cl on a DM basis) for 2 weeks. After a 1-week wash-out period, each group was switched to the opposite diet for 2 weeks. During each 2-week study period, food and water intake, urine volume, urine specific gravity, and urine osmolality were measured daily. Systolic blood pressure (calculated as the mean of 5 readings measured with a Doppler flow detector) was assessed twice daily. No significant effect of diet composition was found on systolic blood pressure, and blood pressure measurements remained within reference limits throughout the study in all 10 cats. However, animals fed the higher salt diet had significantly increased water intake and urine osmolality, and significantly decreased urine specific gravity in comparison to animals fed the control diet. Examination of results of this preliminary study suggests that feeding a diet with moderately increased salt content increases water intake and causes diuresis without increasing systolic blood pressure in healthy adult young cats.  相似文献   

10.
Objective: To determine a reference interval of whole blood and plasma osmolalities for dogs using the Advanced Micro Osmometer Model 3300, to compare calculated osmolarity to measured osmolality, to determine a reference osmole gap, and to determine the best formula for calculated osmolaity. Design: Prospective, observational. Setting: Tertiary referral and teaching hospital. Animals: One hundred healthy adult dogs. Interventions: None. Measurements: Serum and whole blood biochemistry and osmolality assessments. Results: The mean and median of the measured whole blood osmolality were 323 and 320 mOsm/kg, respectively, with a standard deviation of 13.2 mOsm/kg. The mean and median of the measured plasma osmolality were 313 and 310 mOsm/kg, respectively, with a standard deviation of 13.2 mOsm/kg. The formula that was closest to predicting the measured whole blood and plasma osmolality was ((1.86(Na+K))+(BUN/2.8)+(Glucose/18))/0.93 followed closely by the traditional formula of (2(Na+K))+(BUN/2.8)+(Glucose/18). The mean calculated osmolarities using these formulas were 314.1 and 313.25 mOsm/L, respectively. The mean osmole gap using these formulas was 3.49 and 4.41 mOsm, respectively, for whole blood and ?2.01 and ?1.1 mOsm, respectively, for plasma. Conclusion: The Advanced Micro Osmometer Model 3300 was successful in measuring the osmolality in relative agreement with the current published reference intervals for osmolality. Measured osmolality correlated well with traditional calculated osmolarity.  相似文献   

11.
Bioavailability and pharmacological effects of tiludronate were compared when administered as an intravenous (i.v.) bolus at a dosage of 0.1 mg/kg body weight (b.w.) once daily for 10 consecutive days (group 1, n  = 6) and as a single constant rate infusion (CRI) at a total dose of 1 mg/kg b.w. (group 2, n  = 6) in healthy adult horses.
Tiludronate and carboxy-terminal cross-linking telopeptide of type I collagen (CTX-1) were measured in plasma and urine.
There was no statistically significant difference in area under the curve ( AUC ) and clearance ( Cl ) between the two groups. Bioavailability of the CRI was 103% (not significantly different) that of the 10 daily i.v. bolus doses. Cumulative urine tiludronate excretion could not be compared between groups because of poor sensitivity of the assay in urine. Plasma and urine CTX-1 levels were not different between groups throughout the study. However, interindividual variations were greater in group 1 than in group 2. A significant decrease in CTX-1 levels was observed in plasma after the first administration in group 1, but not in urine; while in group 2, a significant decrease in CTX-1 concentrations was observed after treatment in both plasma and urine.
In conclusion, both dosage regimens of tiludronate produced similar plasma exposure and pharmacological effects in adult healthy horses.  相似文献   

12.
The disposition kinetics and urinary excretion of gentamicin sulphate were studied in young buffalo bulls following a single intramuscular administration of the drug at 5 mg kg-1 body weight. The time course of the serum gentamicin concentration was adequately described by the one-compartment open model. The values of the absorption and elimination halflives were 12.2±2.2 and 167.0±29.7 min respectively. The apparent volume of distribution was 0.29±0.01 L kg-1. During the first 12 h, 63% of the total administered dose was excreted in urine. On the basis of the kinetic data, a satisfactory intramuscular dosage regimen for gentamicin sulphate would be at least 6 mg kg-1 body weight repeated at 8 h intervals.  相似文献   

13.
The correlation between 24-hour urinary excretion of N -acetyl-β- d -glucosaminidase (NAG) and γ-glutamyl transferase (GGT) with urine NAG and GGT/creatinine ratios was assessed in dogs with gentamicin-induced nephrotoxicosis. Eighteen 6-month-oid male Beagles with normal renal function were randomly divided into 3 groups of 6. Each group was fed a different concentration of protein (high protein, 27.3%; medium protein, 13.7%; and low protein, 9.4%) for 21 days. After dietary conditioning, gentamicin was administered at a dose of 10 mg/kg IM tid for 8 days and each group was continued on its respective diet. Endogenous creatinine clearance and 24-hour urinary excretion of NAG and GGT were determined after dietary conditioning (day 0) and on days 2, 4, 6, and 8 of gentamicin administration. In addition, urine NAG and GGT/creatinine ratios (IU/L ± mg/dL) were determined from catheterized spot urine samples obtained between 7 and 10 am on the same days. The correlation between 24-hour urinary enzyme excretion and urine enzyme/creatinine ratio in the spot urine samples was evaluated by simple linear regression analysis. Spot sample urine enzyme/creatinine ratios were significantly correlated with 24-hour urinary enzyme excretion through day 4 for dogs on low dietary protein, through day 6 for those on medium protein, and through day 8 for those on high dietary protein. Mean ± SD baseline values for urine NAG/creatinine ratio and 24-hour urinary NAG excretion were 0.06 ± 0.04 and 0.19 ± 0.14 IU/kg/24 hr, respectively. Baseline values for urine GGT/creatinine ratio and 24-hour urinary GGT excretion were 0.39 ± 0.18 and 1.42 ± 0.82 IU/kg/24 hr, respectively.  相似文献   

14.
Four mares and four geldings of Quarter Horse and Thoroughbred breeding were used in two simultaneous 4x4 Latin square experiments to study the effects of dietary cation-anion balance (DCAB), defined as meq ((Na+K)-C1)/kg dry matter, on urinary pH and mineral excretion in exercised horses. Diets consisted of a pelleted concentrate of corn, soybean meal and cottonseed hulls fed with bermudagrass hay. Treatments with DCAB of +5 (Low, L), +107 (Medium Low, ML), +201 (Medium High, MH) and +327 (High, H), meq ((Na+K)-Cl)/kg dry matter were formed by supplementing diet L with calcium chloride and ammonium chloride, diet ML with calcium chloride and diet H with sodium bicarbonate and potassium citrate (Table 1). Diet MH was not supplemented and served as the control treatment. Horses were conditioned aerobically for 6 weeks using long, slow, distance (LSD) workouts. During the experimental periods, horses were subjected to a combined exercise regimen alternating LSD with an interval-training protocol 6 days/week. There was a significant (P<.01) treatment effect on urine pH; least squares means for L, ML, MH and H were 6.73, 7.17, 7.38, and 7.92. Horses consuming diet L excreted more calcium in the urine (P<.05) than those consuming MH or H. Least squares means for daily urine calcium excretion tended to be linear across treatments and ranged from 19.66 g/day for diet L to 9.12 g/day for diet H. Urinary chloride excretion was higher (P<.05) for L than for MH or H. Horses fed diet H excreted more sodium (P<.05) in urine than horses fed the other diets. Lowering DCAB, increases urinary calcium loss; depending on the level of calcium intake, this could lead to negative calcium balance in exercising horses.  相似文献   

15.
Serum and urine were taken from healthy dairy cattle from 22 different farms. 214 animals belonged to the Swiss Brown breed and 210 were crossbreds of Simmental-Red Holstein. The animals were given at least 70 g of sodium chloride with their daily feed ration. On 6 farms sodium chloride was offered ad libitum in form of licks, which was presumed to be sufficient for covering their needs. Concentrations of sodium (UR Na), potassium (UR K) and creatinine were analyzed from serum and urine and fractional excretion of Na and K was calculated. Concentrations of sodium and potassium in urine from all cows (mean +/- sd) was 60.9 +/- 44.7 mmol/l and 370.7 +/- 66.9 mmol/l respectively. The FE values were 0.954 +/- 0.939% for sodium and 173.1 +/- 54% for potassium. In 5.5% of the animals values for UR Na < 10 mmol/l were found. There were no significant differences, however, were found in sodium and potassium excretion among farms. Urine samples of at least 10 animals should be analyzed in order to have a reliable estimation of the supply with sodium chloride within a herd. Our results do not support the hypothesis that low sodium excretion would be a predisposing factor for Bovine Dilative Cardiomyopathy in Simmental-Red Holstein cattle.  相似文献   

16.
Effects of xylazine on renal function and plasma glucose in ponies   总被引：2，自引：0，他引：2  
The intravenous administration of xylazine (1.1 mg/kg bodyweight) in six ponies resulted in a significant increase in urine output over two hours, with maximum flow occurring between 30 and 60 minutes after injection. Urine specific gravity, osmolality and glucose concentration decreased. Renal clearance of endogenous creatinine was unchanged. Significant increases in the excretion of potassium and chloride occurred. Plasma glucose concentration was increased 30 minutes after the administration of xylazine by a mean value of 37 per cent. Serum osmolality and sodium, potassium and chloride concentrations remained unchanged.  相似文献   

17.
In the present study, the daily excretion of potassium (K) in urine (urinary K(UK)) was estimated from a 6 h urine sample using urinary creatinine (UC) as the index substance. All urine was collected from six pregnant Holstein cows at 6 h intervals for 24 h on 3 days of the 4th, 2nd and final week before the expected date of parturition. In total, 72 6 h urine samples were obtained. Daily UC excretion (mg/day per kg bodyweight (BW)) was almost the same for the three sampling days. Daily UC excretion varied among cows from 22.1 to 24.3 mg/day per kg BW with a mean of 22.8 mg/day per kg BW with no significant difference. Thus, daily UC excretion was confirmed to be constant throughout the prepartum period with no differences among individuals. The concentration ratios of K to creatinine ((UK mg/dL)/(UC mg/dL) (UK/UC)) correlated strongly to the hourly K excretions (mg/h per kg BW) (r = 0.952, P < 0.01) in the 6 h urine samples. The differences in the UK/UC ratio between sampling periods were not significant within each cow. Therefore, daily UK excretion (mg/day) can be estimated using the equation: daily UK excretion (mg/day) = daily UC excretion (mg/day per kg BW) × BW (kg) × 6 h urine sample UK/UC, where daily UC excretion can be a given value.  相似文献   

18.
Blood and urine chemical values at parturition in clinically normal Holstein cows (n = 12) were compared with the same values in Holstein cows developing udder edema (n = 12). There was no statistically significant mean difference between the 2 groups for the serum and urine chemical data. Furosemide (500 mg) given IV caused a significant increase in serum calcium and sodium, urine chloride, potassium, and sodium, and fractional excretional ratio of chloride, potassium, and sodium. There was a significant mean decrease in the serum potassium, urine creatinine, osmolality, pH, and specific gravity. Hydrochlorothiazide (250 mg) given IV caused a significant mean increase in serum chloride, urine chloride, potassium, and sodium, and fractional excretion ratio of chloride, potassium, and sodium. There was a significant mean decrease in serum potassium and sodium, urine osmolality, pH, and specific gravity. Acetazolamide (500 mg) given IV caused a significant mean increase in blood urea nitrogen, serum chloride and glucose, urine sodium, and fractional excretion ratio of sodium, while causing a significant mean decrease in serum potassium, sodium, and phosphorus, and urine creatinine. Dextrose (500 g) given IV as a 50% solution caused a statistical mean increase in serum glucose, urine chloride, potassium, and sodium, and fractional excretion ratio of chloride and potassium. A statistical mean decrease occurred in the packed cell volume, blood urea nitrogen, serum calcium, potassium, sodium, and phosphorus, urine creatinine, osmolality, and pH.  相似文献   

19.
Acute nephrotoxicosis was induced in ewes by daily SC administration of gentamicin. Activity of 3 urine enzymes, gamma-glutamyltransferase (GGT), beta-N-acetylglucosaminidase (AGS), and beta-glucuronidase (GRS), were measured during the development of aminoglycoside nephrotoxicosis. Measurements from timed, volume-measured urine samples were performed on days 0, 7, and 8. Measurements from urine samples obtained without volume measurement (spot samples) were performed daily. Urine GGT and AGS activities were high 3 days prior to detection of high serum creatinine concentration and 1.5 days before the appearance of casts in the urine sediment; values consistently remained in the abnormal range until termination of the study. High urine GRS activity was inconsistent and transient; serum GGT activity did not change during the course of the study. Urine GGT and AGS activities expressed as total excretion per unit time and body weight, enzyme activity per unit volume, and as ratio of urine enzyme activity to urine creatinine concentration were strongly correlated. Urine GGT and AGS, but not GRS activities, are suitable indicators of renal tubular cell damage in sheep with aminoglycoside nephrotoxicosis. Urine GGT and AGS activities indicate cellular changes occurring several days prior to the first indications of renal functional change.  相似文献   

20.
The pharmacokinetics and dosage regimen of cefotaxime following its single subcutaneous administration (10 mg/kg) were investigated in buffalo calves. Plasma and urine samples were collected over 10 and 24 h post administration, respectively. Cefotaxime in plasma and urine was estimated by microbiological assay technique using E. coli as test organism. The pharmacokinetic profiles fitted one-compartment open model. The peak plasma levels of cefotaxime were 6.48 ± 0.52 µg/ml at 30 min and the drug was detected upto 10 h. The absorption half-life and elimination half-life were 0.173 ± 0.033 h and 1.77 ± 0.02 h, respectively. The apparent volume of distribution and total body clearance were 1.17 ± 0.10 l/kg and 0.45 ± 0.03 l/kg/h, respectively. The urinary excretion of cefotaxime in 24 h, was 5.36 ± 1.19 percent of total administrated dose. A satisfactory subcutaneous dosage regimen for cefotaxime in buffalo calves would be 13 mg/kg repeated at 12 h intervals.  相似文献   

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