Chrononephrotoxicity in rat of a vancomycin and gentamicin combination.

The effect of time of administration on excretion of two brush border enzymes--alanine aminopeptidase (AAP) and gamma-glutamyl transferase (gamma GT), and a lysosomal enzyme, N-acetyl-beta-D-glucosaminidase (NAG) with a single high dose of vancomycin, gentamicin or a combination of vancomycin and gentamicin was studied in male Wistar rats and compared with elimination of a control group. The rats received vancomycin intraperitoneally (200 mg.kg-1), gentamicin intramuscularly (100 mg.kg-1) or the combination of the drugs by the same route. A control group received isotonic NaCl solution. The four groups of animals received a single injection at 8 a.m., 2 p.m., 8 p.m., and 2 a.m. and urine excretion values for AAP, gamma GT and NAG were determined 24 hr later. The results show that the nephrotoxicity of gentamicin + vancomycin is greater than that observed with gentamicin, which again is greater than that observed with vancomycin. Furthermore, circadian variations in renal toxicity were observed, the least occurring at 8 a.m.     

A critical review of the dosage of teicoplanin in Europe and the USA

The glycopeptide antibiotic, teicoplanin, is increasingly used in Europe in the treatment of Gram-positive infection. It is administered as a bolus once daily, it has little potential for nephrotoxicity, and serum monitoring is usually unnecessary. However, poor results were reported in early trials at a daily dose of 200 mg and, more recently, at 400 mg/day in monotherapy of staphylococcal endocarditis. While 400 mg (6 mg/kg day(-1)) is now standard, US trials have tried very high doses in an attempt to improve its efficacy in monotherapy of deep-seated staphylococcal sepsis. European centres continue to use 6 mg/kg day(-1) as the usual maintenance dose and 6-12 mg/kg as the loading dose. For the more difficult cases, teicoplanin is used in combination with other agents. All available published and unpublished literature was reviewed to try to solve these problems. With the exception of endocarditis, failure rates in the 84 European open studies varied more between trials than between the dosages used. In 32 European and eight US randomized trials, a dose of 6 mg/kg day(-1) of teicoplanin was effective, except in staphylococcal endocarditis if teicoplanin was used as monotherapy. In that case, 12 mg/kg day(-1) or more was needed to achieve a cure rate similar to that of vancomycin. Treatment was most successful with trough levels over 20 mg/l. However, lower doses were effective in combination with aminoglycosides, as is common in clinical practice. An open trial suggested that 12 mg/kg day(-1) was needed for treatment of septic arthritis. It is suggested that 6 mg/kg day(-1) of teicoplanin be used for all indications except staphylococcal endocarditis and septic arthritis when it should be given in a dose of 12 mg/kg day(-1) or in combination with other agents.     

Functional and structural alterations of the rat kidney induced by the naturally occurring organonitrile 2S-1-cyano-2-hydroxy-3,4-epithiobutane

The organonitriles, 2S-1-Cyano-2-hydroxy-3,4-epithiobutane (erythro and threo) (CHEB), isolated from the seed of Crambe abyssinica were administered by gavage to male Fischer-344 rats. Rats given 50 mg/kg/day were killed at 24, 48, and 72 hr. The rats given 100 mg/kg/day were killed at 48 and 72 hr. Serum urea nitrogen and creatinine were increased by 48 hr and further elevated by 72 hr. Glomerular filtration rate (GFR) of the 50 mg/kg CHEB rats was elevated at 24 hr but fell to subnormal values by 72 hr. The GFR of the 100-mg/kg group was decreased at 48 and 72 hr. Urine output of the 50-mg/kg group increased continuously through 72 hr, while urine output of the 100-mg/kg group was increased to a lesser degree. Urinary N-acetyl-beta-D-glucosaminidase (NAG) activity (nmol/hr/mg creatinine) was significantly elevated in both groups by 48 hr, and further increased by 72 hr. Twenty-four hours after administration of 50 mg/kg, renal proximal tubular epithelial cells of some rats had fine cytoplasmic vacuolation. At 48 and 72 hr, necrosis and coarse vacuolation of proximal tubular epithelial cells occurred in both dose groups. The necrosis was most severe at the apexes of the medullary rays and the coarse vacuolation extended deeply toward the outer stripe of the outer zone of the medulla. Higher doses and/or longer times of CHEB administration resulted in a more extensive lesion distribution. It is concluded that CHEB induces nephrotoxicity in rats characterized by nonoliguric, acute renal failure, and morphological lesions preferentially involving the pars recta of the proximal tubules.     

庆大霉素应用在气腹时的肾毒性实验研究

目的：研究气腹是否会加强大鼠的庆大霉素的肾毒性。方法：收集28只大鼠中24h的尿液。气腹组（n=7),在15mmHg压力下持续2h腹腔注入二氧化碳。庆大霉素组（n=7),静脉注射9mg/kg庆大霉素。气腹结合庆大霉素组（n=7),在气腹前10min给相同剂量的庆大霉素。操作后,收集24h尿液,7d后检测血液肌酐并收集最后24h尿液。对所有的尿液样品进行肌酐和NAG（N-acetyl-beta-glucosaminidase)的定量分析。结果：庆大霉素组和气腹结合庆大霉素这两组表现出第一的NAG排泄明显大于同一天空白组或操作前的量。第一天和第七天尿液的剩余肌氨酸酐和NAG的量同一天空白组和操作前对应的量没有显著的差别。在这些组中第七天的血清肌酐和肌酐清除率没有显著差异。结论：给大鼠静脉注射庆大霉素会使尿液的NAG排出量暂时性增加,NAG排出量在7d内达到稳定。单独2h 15mmHg气腹或合并庆大霉素治疗不会增加大鼠的尿液NAG。而且肯定了庆大霉素加气腹不会使肌酐清除量减少超过60％。这些结果不支持“气腹会加强庆大霉素的肾毒性”的假设。     

Nephrotoxicity following acute administration of N-(3,5-dichlorophenyl)succinimide in rats

The acute renal effects of the fungicide N-(3,5-dichlorophenyl)succinimide (NDPS) were studied in male Sprague-Dawley rats. NDPS (50 mg/ kg, i.p.) increased urine volume and decreased food intake and body weight at 24 h but not 48 h. No change in urine content of the accumulation by renal cortical slices of the organic anion p-aminohippurate (PAH) or the organic cation tetraethylammonium (TEA) was observed with 50 mg/kg NDPS when compared to control animals. Rats receiving 100 or 200 mg/kg NDPS (i.p.) exhibited increased urine volume, proteinuria, glucosuria, decreased food intake and body weight, increased BUN and decreased accumulation of PAH and TEA at both 24 h and 48 h. These effects were generally more pronounced at the 200 mg/kg dose level. Pair-fed control experiments demonstrated that renal effects were NDPS-induced and not related to daily food consumption. No change in water intake was observed with any dose of NDPS used. The results demonstrate that NDPS alters renal function in a dose-dependent manner. In addition, NDPS (50 mg/kg) is capable of producing diuresis without apparent nephrotoxicity while doses of 100 mg/kg or more produce diuresis and nephrotoxicity.     

Teicoplanin vs. vancomycin for the treatment of serious infections: a randomised trial

A prospective, randomised study of 56 patients comparing teicoplanin with vancomycin for suspected or proven severe Grampositive infection was conducted. The majority of infections were soft tissue infections (8 teicoplanin; 16 vancomycin) and by chance a significantly higher number of Hickman catheter-related infections occurred in the vancomycin arm (4 vs. 14, P < 0.01). Teicoplanin was administered as a single daily dose of 400 mg iv or im; 5 patients received 200 mg following the initial dose of 400 mg. Vancomycin was given 1 g every 12 h. Fifty-four patients were evaluable for efficacy (26 teicoplanin, 28 vancomycin). Of these, 18 episodes in 17 patients (teicoplanin) and 19 episodes in 18 patients (vancomycin) gave an evaluable clinical response, the success rates being similar (76% teicoplanin; 68% vancomycin). Staphylococcus aureus was the most common pathogen isolated; all pathogens were susceptible to both glycopeptides with MICs < 4 mg/l. Bacteriological elimination rates were similar in both groups (71% teicoplanin; 78% vancomycin). Significantly more patients given vancomycin experienced adverse events (7 teicoplanin; 16 vancomycin; P = 0.03). This caused treatment to be discontinued in 4 cases, compared with only one receiving teicoplanin. The most common vancomycin-related events were histamine-associated reactions (15 patients), including 2 cases of Red Man Syndrome, and nephrotoxicity (5 patients). There were no histamine-mediated events and only one case of nephrotoxicity with teicoplanin. Teicoplanin and vancomycin show similar clinical and bacteriological efficacy and teicoplanin is significantly less toxic and easier to use in patients with severe infection.     

Lack of hepato- and nephrotoxicity induced by antifungal drug voriconazole in laboratory rats

Voriconazole is a new, potent broad-spectrum triazole systemic antifungal drug, a second-generation azole antifungal that is increasing in popularity, especially for the treatment of invasive aspergillosis and fluconazole-resistant invasive Candida infections. However, it is also known to induce hepatotoxicity clinically. The aim of this study was to investigate the hepatotoxicity and nephrotoxicity potential of voriconazole in vivo in rats. Forty rats were treated intraperitoneally with voriconazole as single (0, 10, l00, and 200 mg/kg) or repeated (0, 10, 50, and l00?mg/kg per day for 14 days) doses. Venous blood was collected for the repeated-dose group on days 1 and 14. Rats were sacrificed 24 hours after the last dose. Body weight, liver weight, and kidney weight of rats were recorded. Livers and kidneys samples were taken for histological and transmission electron microscopy (TEM) analysis. Results revealed that voriconazole had no effects on serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphotase, gamma glutamyl transpeptidase, blood urea nitrogen, and creatinine for both the single- and repeated-dose groups. However, histologically, in the repeated 50- and 100-mg/kg voriconazole-treated rats, mild focal inflammation was observed. Under TEM, only small changes in the 100 mg/kg/day group were revealed. These results collectively demonstrated that voriconazole did not induce significant hepatotoxicity and nephrotoxicity, even at very high doses.     

Protective effect of fleroxacin against the nephrotoxicity of isepamicin in rats

The protective effect of fleroxacin on isepamicin-induced nephrotoxicity was investigated. Wistar rats were administered either fleroxacin 100 mg/kg orally, isepamicin 300 mg/kg subcutaneously, or fleroxacin and isepamicin in combination for 14 d. The animals given 300 mg/kg of isepamicin showed a significant increase in urine N-acetyl-beta-D-glucosaminidase (NAG) levels as compared with the control animals which received saline (p<0.01). However, the increase in NAG level was markedly less when isepamicin was administered in combination with fleroxacin (p<0.01). Fleroxacin alone had no effect on urine NAG activity. Serum creatinine and blood urea nitrogen (BUN) levels were significantly higher in animals treated with isepamicin alone than in the control animals (p<0.01) or animals receiving the isepamicin fleroxacin combination (p<0.01). Histopathologically, fleroxacin induced very few cellular alterations, but considerably reduced the manifestation of typical signs of isepamicin nephrotoxicity. This investigation demonstrates that fleroxacin protects animals against isepamicin-induced nephrotoxicity.     

Effects of various pretreatments on the acute nephrotoxic potential of styrene in Fischer-344 rats

The effects of various inducers and inhibitors of hepatic microsomal mixed-function oxidase (MFO) system and diethylmaleate treatment on styrene-induced acute nephrotoxicity in male Fischer-344 rats were studied. Groups of rats were pretreated with either 3-methylcholanthrene (15 mg/kg, i.p., 3 days), or phenobarbital (80 mg/kg, i.p., 3 days), or SKF525-A (50 mg/kg, i.p., 1 h), or piperonyl butoxide (300 mg/kg, i.p., 2 h), or diethylmaleate (400 mg/kg, i.p., 90 min) prior to an i.p. administration of styrene (0, 0.6 and 0.9 g/kg) in corn oil. The uptake of p-aminohippurate (PAH) by renal cortical slices, the morphology of renal cortices, as well as urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG) and gamma-glutamyl transpeptidase (gamma-GT) of control and pretreated rats were examined 24 h after styrene. The inducers and inhibitors of MFO system failed to modify further the acute nephrotoxicity of styrene. On the other hand, diethylmaleate pretreatment not only reduced further the uptake of PAH, but also produced further significant increase in the urinary excretion of NAG and gamma-GT observed at the higher dose of styrene. Similarly, ultrastructural studies showed a moderate increase in the severity of kidney damage induced at the higher dose of styrene due to pretreatment with diethylmaleate. These data suggest that tissue glutathione concentrations and hence, corresponding conjugating activity might be important determinants of styrene nephrotoxicity. The results further indicate that a metabolic activation system not involving certain cytochrome P-450 might be responsible in styrene-induced nephrotoxicity.     

Unexpected nephrotoxicity induced by tetrabromobisphenol A in newborn rats

The repeated dose toxicity of tetrabromobisphenol A (TBBPA), a flame retardant, was examined in male and female newborn rats given TBBPA orally at 0, 40, 200, or 600 mg/kg per day for 18 days from 4 days of age until weaning at 21 days of age. Half the rats in each dose group were sacrificed for a full gross necropsy and a histopathology on the organs and the tissues at 22 days of age and the remaining rats were reared without any treatment from post-weaning until 84 days of age to examine the recovery and the delayed occurrence of toxic effects. Treatment with 200 or 600 mg/kg TBBPA-induced nephrotoxicity characterized by the formation of polycystic lesions, and some deaths occurred in the 600 mg/kg group. There was no gender difference of nephrotoxicity and there were no other critical toxicities. At 85 days of age, nephrotoxic lesions were still present in the 200 and 600 mg/kg groups, but no abnormalities indicating delayed occurrence of toxic effects were found in the treated groups. In order to investigate the specificity of the nephrotoxicity induced by TBBPA in newborn rats, TBBPA was given to male and female young rats (5 weeks old) by oral administration at 0, 2000, or 6000 mg/kg per day for 18 days. The kidneys showed no histopathological changes even at the high dose. These results clearly indicate that the nephrotoxicity of TBBPA is specific for newborn rats although the toxic dose level was relatively high. To gain insight into the possible effects on human infants, the mechanism of this unexpected nephrotoxicity of TBBPA in newborn rats should be examined.     

紫背天葵提取物对糖尿病肾病大鼠的作用

目的研究紫背天葵提取物对糖尿病肾病大鼠的作用。方法 SD大鼠一次性腹腔注射链脲佐菌素(STZ),建立糖尿病肾病大鼠模型。紫背天葵提取物(5 g/kg)灌胃4周后,收集大鼠24 h尿液,检测尿液中尿蛋白(UP)、N-乙酰β-D-氨基葡萄糖苷酶(NAG)和β2-微球蛋白(β2-MG)的含量;测定肾脏指数;测定血清中尿素氮(BUN)、肌酐(Cr)和β2-MG的含量。结果紫背天葵提取物能明显降低糖尿病肾病大鼠24 h排尿量、尿蛋白、β2-MG和NAG(P<0.01或0.05);使肾脏指数下降(P<0.05);同时能够降低血清中BUN、Cr和β2-MG含量(P<0.01或0.05)。结论紫背天葵提取物可以改善肾脏滤过功能,明显改善糖尿病肾病大鼠临床症状。     

Nephrotoxicity of hexachloro-1:3-butadiene in the rat: The effect of age,sex, and strain

Adult male rats are less susceptible to hexachloro-1:3-butadiene-induced nephrotoxicity than adult female and young male rats. A single dose of 50 mg/kg hexachloro-1:3-butadiene (HCBD) ip in adult Alderley Park (Wistar-derived) females produced marked renal tubular necrosis and an increased plasma urea by 24 hr. Young male rats were also more susceptible to HCBD-induced nephrotoxicity; a dose of 25 mg/kg produced marked tubular necrosis and an increased plasma urea in 21-day-old rats, while a dose of 200 mg/kg was required to produce a similar response in adult males. p-Aminohippurate accumulation by thin slices of renal cortex from rats treated 24 hr previously with HCBD was reduced in adult but not in young male rats. HCBD was more toxic to young male rats (21 and 29 days old, LD50 57 and 96 mg/kg. respectively) than to adult males (7 weeks old, LD50 360 mg/kg). HCBD administration produced a more marked nephrotoxicity in 21-day-old rats treated with phenobarbital in their drinking water for 7 days than in rats of the same age not treated with phenobarbital. Associated with the increased susceptibility of female rats, renal nonprotein sulfhydryl content (NP-SH) was decreased in female but not in male rats 4 hr after HCBD administration. This decrease suggests conjugation of HCBD by the female rat kidney. The sex and age differences observed in nephrotoxicity due to HCBD are probably related to differences in hepatic and renal enzymes responsible for the detoxification and/or activation of HCBD. Fischer 344 rats were slightly more susceptible and Long Evans rats slightly less susceptible than the Alderley Park strain to HCBD-induced nephrotoxicity, although the differences were not as marked as those seen with age and sex.     

Studies on the nephrotoxicity of aminoglycoside antibiotics and protection from these effects (4). Effects of tobramycin alone and in combination with latamoxef on the stability of rat kidney lysosomal membranes

Effects of tobramycin (TOB) alone and in combination with latamoxef (LMOX) on the stability of rat kidney lysosomal membranes were investigated. Rats were injected with doses of TOB (90 mg/kg/day, s.c.) alone. LMOX (2,000 mg/kg/day, s.c.) alone or TOB (90 mg/kg/day, s.c.) and LMOX (2,000 mg/kg/day, s.c.) for 5 consecutive days. The rat kidney lysosomes were isolated on the 1st, 3rd and 5th days and incubated in a 0.25 M sucrose solution containing 1 mM EDTA (pH 7.0) at 37 degrees C for 20 min. After incubation, the activity of N-acetyl-beta-D-glucosaminidase (NAG) released from lysosomes was measured, and the percent NAG release was calculated as an index of the stability of lysosomal membranes. The percent releases of NAG from lysosomes of TOB alone-treated rats were 40 and 50% greater than those of normal rats on the 1st and 3rd days, respectively. On the other hand, treatment with TOB and LMOX suppressed the NAG release from lysosomes with TOB alone by about 80 to 100%. There were insignificant slight increases in the percent NAG release in LMOX alone-treated rats on the 3rd and 5th days. In addition, the in vitro study indicated that incubation of the lysosomal fraction from kidneys of normal rats with TOB (30 micrograms/ml) significantly increased the NAG release, compared with that of the non-treated lysosomal fraction. However, the preincubated mixture of TOB (30 micrograms/ml) and LMOX (50 micrograms/ml) in vitro significantly suppressed the release of NAG from lysosomes by 85%. These results suggest that the suppression of the releases of NAG from lysosomes by the combination of TOB with LMOX may contribute to the protective effect of LMOX against TOB nephrotoxicity.     

Protective effects of lutein against vancomycin-induced acute renal injury in mice via upregulation of peroxisome proliferator-activated receptor gamma/nuclear factor erythroid 2-related factor 2 and inhibition nuclear factor-kappaB/caspase 3

Vancomycin, an antibiotic used occasionally as a last line of treatment for methicillin-resistant Staphylococcus aureus, is reportedly associated with nephrotoxicity. This study aimed at evaluating the protective effects of lutein against vancomycin-induced acute renal injury. Peroxisome proliferator-activated receptor gamma (PPARγ) and its associated role in renoprotection by lutein was also examined. Male BALB/c mice were divided into six treatment groups: control with normal saline, lutein (200 mg/kg), vancomycin (250 mg/kg), vancomycin (500 mg/kg), vancomycin (250 mg/kg) with lutein, and vancomycin (500 mg/kg) with lutein groups; they were euthanized after 7 days of treatment. Thereafter, samples of blood, urine, and kidney tissue of the mice were analyzed, followed by the determination of levels of N-acetyl-β-D-glucosaminidase (NAG) in the urine, renal creatine kinase; protein carbonyl, malondialdehyde, and caspase-3 in the kidney; and the expression of PPARγ, nuclear factor erythroid 2-related factor 2 (Nrf2), and nuclear factor-kappaB (NF-κB) in renal tissue. Results showed that the levels of protein carbonyl and malondialdehyde, and the activity of NAG, creatine kinase and caspase-3, were significantly increased in the vancomycin-treatment groups. Moreover, the levels of Nrf2 significantly decreased, while NF-κB expression increased. Lutein ameliorated these effects, and significantly increased PPARγ expression. Furthermore, it attenuated vancomycin-induced histological alterations such as, tissue necrosis and hypertrophy. Therefore, we conclude that lutein protects against vancomycin-induced renal injury by potentially upregulating PPARγ/Nrf2 expression in the renal tissues, and consequently downregulating the pathways: inflammation by NF-κB and apoptosis by caspase-3.     

Effects of 1,3-dichloropropene on the kidney of Fisher 344 rats after pretreatment with diethyl maleate, buthionine sulfoximine, and aminooxyacetic acid

Acute nephrotoxicity of cis/trans-1,3-dichloropropene (DCP) was assessed in male Fisher 344 rats. Pretreatment of rats with corn oil, aminooxyacetic acid (AOA), buthionine sulfoximine (BSO), or diethyl maleate (DEM) was given intraperitoneally 1 h or 4 h prior to injection of DCP. Doses of DCP were 0, 25, 50, and 75 mg/kg intraperitoneally (4-5 animals per dose/pretreatment group). Urine was collected for 24 h. Excretion of creatinine, phosphorus, protein, N-acetylglucosaminidase (NAG), and the major metabolite of DCP, N-acetyl-S-(cis-3-chloroprop-2-enyl)-cysteine (3CNAC), was measured. Excretion of the metabolite, 3CNAC, increased in a dose-related manner from 0 to 50 mg/kg of DCP, but further increases were not seen at the 75 mg/kg dose. The pretreatments produced no alterations in the amounts of metabolite excreted when compared to corn oil controls. Zero-order metabolism or impaired metabolism is suggested to be occurring at high doses of DCP. The AOA pretreatment group showed no increase in the excretion of NAG, whereas other pretreatments (corn oil, BSO, DEM) showed elevations of NAG excretion at the highest DCP doses. AOA inhibits renal beta-lyase, an enzyme that mediates cleavage of mercapturic acid metabolites to toxic products. Since NAG excretion was not elevated in response to DCP with AOA pretreatment and was not raised by pretreatments that deplete glutathione, it is suggested that nephrotoxic effects of DCP may be mediated through the mercapturic acid metabolites on the kidney, rather than due to glutathione depletion per se.     

Studies of acute nephrotoxic potential of trichloroethylene in Fischer 344 rats

Group of male Fischer 344 rats, after pretreatment with phenobarbital (80 mg/kg, ip, 3 d), were treated ip in corn oil with 0, 5.5, 11.0, and 22.0 mmol trichloroethylene (TRI) per kg body weight. Urines were collected 24 h after the treatment and the animals were then sacrificed. The nephrotoxicity of TRI was then studied by measuring certain biochemical parameters characteristic of renal injury and its in vivo metabolism by quantitating the TRI principal urinary metabolites. Treatment of rats with TRI up to 11 mmol/kg did not influence any of the measured biochemical parameters of nephrotoxicity. On the other hand, significant increases in the urinary level of N-acetyl-beta-glucose-D-aminidase (NAG) and glucose as well as serum urea nitrogen were observed at 24 h only at the highest dose level (22 mmol/kg) or TRI. Urinary excretions of both trichloroethanol and trichloroacetic acid reached an apparent saturation at the highest dose level of TRI. In inhalation studies, urinary levels of gamma-glutamyltranspeptidase, NAG, glucose, proteins, and serum urea nitrogen were significantly increased at 24 h when rats were exposed to either 1000 or 2000 ppm TRI for 6 h. The capacity of renal cortical slices to accumulate p-aminohippurate was significantly reduced 24 h after the exposure to 22 mmol TRI/kg (ip), or to 1000 or 2000 ppm TRI. These results have demonstrated that TRI exerts its acute nephrotoxic potential at a very high dose level and produces nephrotoxic insult at the proximal tubular and possibly glomerular regions of the rat kidney, whether exposed by inhalation or by an ip route. These data further indicate an involvement of a capacity-limited metabolism in the expression of acute nephrotoxicity due to TRI in Fischer 344 rats.     

Renal toxicity of propyleneimine: assessment by non-invasive techniques in the rat

The nephrotoxicity of three different dose levels of propyleneimine (10, 20 and 30 microliter/kg body wt) administered intraperitoneally to rats was studied and 20 microliters/kg body weight was found to be the most appropriate sublethal dose. Injection of propyleneimine (10 microliters/kg body wt) produced a small rise in N-acetyl-beta-D-glucosaminidase (NAG) activity, minor histological damage but no change in urine volume. Six rats were injected with 20 microliters/kg body weight, and urine was collected over the following 16 days. An immediate increase in urine volume, osmolality together with a concomitant decrease in specific gravity, was accompanied by a small increase in creatinine excretion and a more marked increase in the sodium and potassium content of urine after the administration of the nephrotoxin. NAG activity increased immediately and peaked on day 3, the activity remained elevated until day 12 when it fell to near normal levels. The activity of both beta-D-galactosidase and beta-D-glucosidase increased 9 days after administration of the nephrotoxin. In contrast, no consistent change was found in the excretion of the brush border marker enzymes, leucine aminopeptidase (LAP), alanine aminopeptidase (AAP) or alkaline phosphatase (ALP). Proteinuria increased sharply the day after injection and remained abnormal. Increased urinary albumin excretion and the predominance of low molecular weight proteins was demonstrated by sodium dodecyl sulphate (SDS) polyacrylamide gel electrophoresis. Evidence is presented that propyleneimine exerts its early toxic effect on the renal papilla.     

Lack of hepato- and nephrotoxicity induced by antifungal drug voriconazole in laboratory rats

Voriconazole is a new, potent broad-spectrum triazole systemic antifungal drug, a second-generation azole antifungal that is increasing in popularity, especially for the treatment of invasive aspergillosis and fluconazole-resistant invasive Candida infections. However, it is also known to induce hepatotoxicity clinically. The aim of this study was to investigate the hepatotoxicity and nephrotoxicity potential of voriconazole in vivo in rats. Forty rats were treated intraperitoneally with voriconazole as single (0, 10, l00, and 200?mg/kg) or repeated (0, 10, 50, and l00?mg/kg per day for 14 days) doses. Venous blood was collected for the repeated-dose group on days 1 and 14. Rats were sacrificed 24 hours after the last dose. Body weight, liver weight, and kidney weight of rats were recorded. Livers and kidneys samples were taken for histological and transmission electron microscopy (TEM) analysis. Results revealed that voriconazole had no effects on serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphotase, gamma glutamyl transpeptidase, blood urea nitrogen, and creatinine for both the single- and repeated-dose groups. However, histologically, in the repeated 50- and 100-mg/kg voriconazole-treated rats, mild focal inflammation was observed. Under TEM, only small changes in the 100?mg/kg/day group were revealed. These results collectively demonstrated that voriconazole did not induce significant hepatotoxicity and nephrotoxicity, even at very high doses.     

Nephrotoxicity of dactimicin, a novel pseudo-disaccharide aminoglycoside possessing the N-formimidoyl group, compared with that of astromicin, amikacin and other aminoglycoside antibiotics in animals

The nephrotoxicity of dactimicin, the first aminoglycoside possessing the N-formimidoyl group, was compared with that of astromicin and, in part, amikacin, ribostamycin, kanamycin and gentamicin as reference aminoglycoside antibiotics. When a dose of 200 mg/kg was given intramuscularly to dehydrated mice, dactimicin caused no change of BUN and serum creatinine, while reference aminoglycosides caused significant elevations of the parameters. In the urinalysis of rats at doses of 40 and 80 mg/kg per day for 11 days or 21 days, dactimicin caused little changes in urinary parameters except for nucleated cells and NAG. In a detailed comparison between dactimicin and astromicin at 20, 40, 80, 120, 180 and 270 mg/kg for 11 or 30 days, dactimicin induced fewer changes in nucleated cells and NAG at high dosages. While dactimicin and astromicin caused no significant changes in BUN and serum creatinine at dosages of 20-270 mg/kg, histological observations using light and electron microscopes revealed that dactimicin consistently showed fewer lesions on the proximal tubular cells than those of astromicin for all dosages. When injected intramuscularly in rats, dactimicin and astromicin showed a similar distribution in the blood and main organs, except for the kidney, in which renal accumulation of dactimicin was about 60% of that of astromicin. Dactimicin slowly degraded in vitro and in vivo to give fortimicin B as a main product which was accumulated in the kidney. Through comparative studies with astromicin, it was disclosed that the N-formimidoyl group of dactimicin did not increase but decreased the nephrotoxicity, probably by suppressing reabsorption of dactimicin via proximal tubular cells.     

Comparative nephrotoxicity of ribostamycin and gentamicin in rats evaluated by urinalysis

The nephrotoxicity of ribostamycin and gentamicin was compared by urinalysis using 18 parameters. When a dose of 40 mg/kg per day was administered intramuscularly to Fischer rats for 14 days, ribostamycin caused little change of parameters in urine volume, urine osmolality, urine protein, maltase and beta 2-microglobulin. A slight increase with ribostamycin was observed in alpha-fucosidase, beta-N-acetylglucosaminidase, leucine aminopeptidase, lactic dehydrogenase (LDH) and potassium, and a moderate increase was observed in acid phosphatase and alkaline phosphatase. On the other hand, gentamicin caused a large alteration in most parameters. Both antibiotics caused a change of the isoenzyme pattern of LDH1-5, but the pattern with ribostamycin was much closer to the normal pattern than with gentamicin. When a dose of 80 mg/kg of ribostamycin was compared with 10 mg/kg of gentamicin, alteration of urinary parameters was almost comparable. Histopathological observations of the kidney specimens of rats given 40 mg/kg per day showed no histological damage with ribostamycin except for a slight increase and enlargement of lysosomes of the proximal epithelial cells. However, significant histological damage was observed with gentamicin, consistent with the results obtained from urinalysis. Renal accumulation of ribostamycin at a single dose of 20 mg/kg was three times less than that of gentamicin. Ribostamycin caused slightly less nephrotoxicity in rats than kanamycin and far less than dibekacin at an equal dosage of 40 mg/kg per day for 14 days.