Evaluation of the developmental toxicity of perfluorooctanesulfonate in the Anuran,Silurana tropicalis

A 150‐day post‐metamorphosis (dpm) partial lifecycle study exposing Silurana tropicalis to <0.03 (control), 0.06, 0.13 0.25, 0.5 and 1.0 mg/L perfluorooctanesulfonate (PFOS) was conducted. A subset of specimens from the control and each treatment were evaluated at metamorphic completion. A significant increase in the median metamorphosis time was observed in the 1.0 mg/L PFOS treatment relative to the control. A modest increase in the occurrence, but not severity, of mild follicular hypertrophy was found in thyroid glands from organisms exposed to the 0.62 and 1.1 mg/L PFOS treatments. At 150 dpm, a concentration‐dependent increase in whole body PFOS residues was measured ranging from 29.6 to 163.5 mg/kg in the 0.05 and 1.1 mg/L PFOS treatments. Decreased body weight and snout‐vent length were noted in specimens exposed to 1.1 mg PFOS/L at the completion of metamorphosis. Body weight was reduced in the 1.1 mg/L PFOS concentration; however, snout‐vent length was not affected by PFOS exposure at 150 dpm. An increased proportion of phenotypic males were noted in the 0.62 and 1.1 mg/L PFOS treatments. Abnormal ovary development characterized by size asymmetry, necrosis and formation of excessive fibrous connective tissue was identified in females exposed to 0.29 and 1.1 mg PFOS/L. Asymmetrically misshaped testes were found at 1.1 mg/L PFOS. Results suggested that PFOS is capable of interfering with S. tropicalis growth before metamorphic completion and growth and gonad development during juvenile development.     

Subchronic effects of perfluorooctanesulfonate exposure on inflammation in adult male C57BL/6 mice

Previous studies indicate that exposure to perfluorooctanesulfonate (PFOS), a ubiquitous and highly persistent environmental contaminant, induces immunotoxicity in mice. However, few studies have specifically assessed the effects of PFOS on inflammation. This study utilized a standard 60‐day oral exposure period to assess the effects of PFOS on the response of inflammatory cytokines [tumor necrosis factor α (TNF‐α), interleukin‐1 β (IL‐1β), and interleukin‐6 (IL‐6)]. Adult male C57BL/6 mice were dosed daily by oral gavage with PFOS at 0, 0.0083, 0.0167, 0.0833, 0.4167, 0.8333 or 2.0833 mg/kg/day to yield a targeted Total Administered Dose (TAD) over 60 days of 0, 0.5, 1, 5, 25, 50, or 125 mg PFOS/kg, respectively. The percentage of peritoneal macrophages (CD11b⁺ cells) was significantly increased at concentrations ≥1 mg PFOS/kg TAD in a dose‐dependent manner. Ex vivo IL‐1β production by peritoneal macrophages was elevated substantially at concentrations of ≥5 mg PFOS/kg TAD. Moreover, PFOS exposure markedly enhanced the ex vivo production of TNF‐α, IL‐1β and IL‐6 by peritoneal and splenic macrophages when stimulated either in vitro or in vivo with lipopolysaccharide (LPS). The serum levels of these inflammatory cytokines observed in response to in vivo stimulation with LPS were elevated substantially by exposure to PFOS. PFOS exposure elevated the expression of pro‐inflammatory cytokines TNF‐α, IL‐1β, IL‐6, and proto‐oncogene, c‐myc, in the spleen. These data suggest that exposure to PFOS modulates the inflammatory response, and further research is needed to determine the mechanism of action. © 2010 Wiley Periodicals, Inc. Environ Toxicol, 2012.     

Effects of di-isononyl phthalate, di-2-ethylhexyl phthalate, and clofibrate in cynomolgus monkeys.

The effects of the peroxisome proliferators di-isononyl phthalate (DINP) and di-2-ethylhexyl phthalate (DEHP) were evaluated in young adult male cynomolgus monkeys after 14 days of treatment, with emphasis on detecting hepatic and other effects seen in rats and mice after treatment with high doses of phthalates. Groups of 4 monkeys received DINP (500 mg/kg/day), DEHP (500 mg/kg/day), or vehicle (0.5% methyl cellulose, 10 ml/kg) by intragastric intubation for 14 consecutive days. Clofibrate (250 mg/kg/day), a hypolipidemic drug used for cholesterol reduction in human patients was used as a reference substance. None of the test substances had any effect on body weight or liver weights. Histopathological examination of tissues from these animals revealed no distinctive treatment-related effects in the liver, kidney, or testes. There were also no changes in any of the hepatic markers for peroxisomal proliferation, including peroxisomal beta-oxidation (PBOX) or replicative DNA synthesis. Additionally, in situ dye transfer studies using fresh liver slices revealed that DINP, DEHP, and clofibrate had no effect on gap junctional intercellular communication (GJIC). None of the test substances produced any toxicologically important changes in urinalysis, hematology, or clinical chemistry; however, clofibrate produced some emesis, small increases in serum triglyceride, decreased calcium, and decreased weights of testes/epididymides and thyroid/parathyroid. The toxicological significance of these small changes is questionable. The absence of observable hepatic effects in monkeys at doses that produce hepatic effects in rodents suggests that DINP, DEHP, and clofibrate would also not elicit in primates other effects such as liver cancer. These data, along with results from in vitro hepatocyte studies, indicate that rodents are not good animal models for predicting the hepatic effects of phthalates in primates, including humans.     

Subchronic toxicity study of sodium o-phenylphenate in mice

A 13-week subchronic oral toxicity study of sodium o-phenylphenate (SOPP) was conducted in B6C3F₁ mice. Body weight gain was significantly depressed in 1.0 and 2.0% SOPP-treated males and in both sexes treated with 4.0%. Urinalysis showed an increase in pH and a decrease of specific gravity in the 4.0% group of both sexes. Relative liver wights of both sexes receiving 1.0, 2.0 and 4.0% SOPP were significantly greater than those of the controls. No treatment-related histopathologic findings were noted. On scanning electron microscopic (SEM) examination, the bladder epithelium of mice given 2.0% SOPP appeared normal at any of the time periods investigated. This study showed that while 4.0% SOPP was very toxic to both sexes, 2.0% SOPP did not cause statistically significant changes in organ weights.     

Toxicity of ammonium perfluorooctanoate in male cynomolgus monkeys after oral dosing for 6 months.

Ammonium perfluorooctanoate (APFO) is a processing aid in the production of fluoropolymers that has been shown to have a long half-life in human blood. To understand the potential toxicological response of primates, groups of male cynomolgus monkeys were given daily po (capsule) doses of either 0, 3, 10, or 30 (reduced to 20) mg/kg/day for 26 weeks. Two monkeys from each of the control and 10 mg/kg/day dose groups were observed for 90 days after the last dose. Clinical observations, clinical chemistry, determination of key hormones, gross and microscopic pathology, cell proliferation, peroxisomal proliferation, bile-acid determination, and serum and liver perfluorooctanoate (PFOA) concentrations were monitored. Toxicity, including weight loss and reduced food consumption, was noted early in the study at the 30 mg/kg/day dose; therefore, the dose was reduced to 20 mg/kg/day. The same signs of toxicity developed in 3 monkeys at 20 mg/kg/day, after which treatment of these monkeys was discontinued. One 30/20 mg/kg/day monkey developed the signs of toxicity noted above and a possible dosing injury, and this monkey was sacrificed in extremis on Day 29. A 3 mg/kg/day dose-group monkey was sacrificed in extremis on Day 137 for reasons not clearly related to APFO treatment. Dose-dependent increases in liver weight as a result of mitochondrial proliferation occurred in all APFO-treated groups. Histopathologic evidence of liver injury was not observed at either 3 or 10 mg/kg/day. Evidence of liver damage was seen in the monkey sacrificed in moribund condition at the highest dose. Body weights were decreased at 30/20 mg/kg. PFOA concentrations in serum and liver were highly variable, were not linearly proportional to dose, and cleared to background levels within 90 days after the last dose. A no observable effect level was not established in this study, and the low dose of 3 mg/kg/day was considered the lowest observable effect level based on increased liver weight and uncertainty as to the etiology leading to the moribund sacrifice of one low-dose monkey on Day 137. Other than those noted above, there were no APFO-related macroscopic or microscopic changes, changes in clinical chemistry, hormones, or urinalysis, or hematological effects. In particular, effects that have been associated with the development of pancreatic and testicular toxicity in rats were not observed in this study.     

Acute toxicity of oral diquat (1,1'-ethylene-2,2'-bipyridinium) in cynomolgus monkeys.

Single doses of 100, 200, 300, and 400 mg diquat ion/kg body wt were administered by stomach tube to cynomolgus monkeys. Within 4 days of dosing deaths occurred in $\text{1}\text{2}$, $\text{0}\text{4}$, $\text{1}\text{2}$, and $\text{2}\text{2}$ monkeys, respectively. All animals developed diarrhea and the most severely affected became comatose. The most important histopathological changes were necrosis of the epithelium and villi of the gastrointestinal tract and of the epithelium of the proximal and distal convoluted tubules of the kidneys.     

Pharmacokinetics of perfluorooctanoate in cynomolgus monkeys.

The pharmacokinetics of perfluorooctanoate (PFOA) in cynomolgus monkeys were studied in a six-month oral capsule dosing study of ammonium perfluorooctanoate (APFO) and in a single-dose iv study. In the oral study, samples of serum, urine, and feces were collected every two weeks from monkeys given daily doses of either 0, 3, 10, or 20 mg APFO/kg. Steady-state was reached within four weeks in serum, urine, and feces. Serum PFOA followed first-order elimination kinetics after the last dose, with a half-life of approximately 20 days. Urine was the primary elimination route. Mean serum PFOA concentrations at steady state in the 3, 10, and 20 mg/kg-day dose groups, respectively, were 81, 99, and 156 microg/ml in serum; 53, 166, and 181 microg/ml in urine; and, 7, 28, and 50 microg/g in feces. Mean liver concentrations reached 16, 14, and 50 microg/g in the 3, 10, and 20 mg/kg groups, respectively. In the iv study, three monkeys per sex were given a single dose of 10 mg/kg potassium PFOA. Samples were collected through 123 days. The terminal half-life of PFOA in serum was 13.6, 13.7, and 35.3 days in the three male monkeys and 26.8, 29.3, and 41.7 days in the three females. Volume of distribution at steady state was 181 +/- 12 and 198 +/- 69 ml/kg for males and females, respectively. Based on the result of both the oral and iv studies, the elimination half-life is approximately 14-42 days, and urine is the primary route of excretion.     

Developmental toxicity assessment of tanezumab,an anti-nerve growth factor monoclonal antibody,in cynomolgus monkeys (Macaca fascicularis)

Two intravenous studies with tanezumab, an anti-nerve growth factor monoclonal antibody, were conducted in pregnant cynomolgus monkeys to assess potential effects on pregnancy and pre- and postnatal development. Study 1 evaluated infants up to 12 months of age following weekly maternal dosing (0, 0.5, 4 or 30 mg/kg; 18 per group) from gestation day (GD) 20 through parturition. Study 2 evaluated infants 2 months postnatally following weekly maternal dosing (0, 0.5 or 30 mg/kg; 20–21 per group) from GD 20 through 48. In the absence of maternal toxicity, tanezumab increased stillbirth and post-birth infant mortality/morbidity, decreased infant growth and resulted in microscopic changes in the peripheral sympathetic and sensory nervous system of the infants at all doses. Decreased primary antibody responses and increased incidences in skin changes in infants were also observed. The no-observed-adverse-effect-level for maternal toxicity was 30 mg/kg and <0.5 mg/kg for developmental toxicity.     

Twenty-six-week repeat-dose toxicity study of a recombinant human granulocyte colony-stimulating factor derivative (nartograstim) in cynomolgus monkeys.

An rhG-CSF derivative, nartograstim (NTG), at dose levels of 0 (saline), 0.1, 1, 10, and 100 microg/kg, was administered subcutaneously to groups of 3 male and 3 female cynomolgus monkeys once daily for 26 weeks to investigate its toxicity. In Week 4 or later, an increase in leukocyte counts consisting mainly of neutrophils was noted in all NTG dose groups, and was considered to be attributable to the pharmacological action of NTG. The degree of this increase was reduced with repetition of dosing. Increases in granulocytic cells and granulocytic cells/erythrocytic cells (G/E) ratio in the bone marrow, increase in serum ALP activity, and enlarged spleens with increase of neutrophils in the red pulp were observed at 10 microg/kg and higher. Anemia was noted at 10 microg/kg and higher in Week 4 and was accompanied by an increase in reticulocytes and a decrease in total cholesterol level at 100 microg/kg. Anti-NTG antibody was detected in 1 female at 100 microg/kg, but neutralizing antibodies were not detected at any dose levels in Week 4. In Weeks 13 and 26, these antibodies were detected sporadically at all dose levels. However, there were considerable individual variations in antibody titer, and no definite correlation could be found between the dose levels and the antibody titer. Seven NTG-dosed animals including 3 high dose-group animals showed obvious increases in leukocyte counts until Week 26 but no obvious elevation of anti-NTG or neutralizing antibody. In these animals, changes including anemia became slighter but were still observed in Week 26. Under the conditions in this study, 1 microg/kg was concluded to be the no-observed-adverse-effect level (NOAEL) in cynomolgus monkeys.     

Developmental toxicity of dibutyltin dichloride given on three consecutive days during organogenesis in cynomolgus monkeys

We previously reported that the administration of dibutyltin dichloride (DBTCl) by nasogastric intubation during the entire period of organogenesis, days 20–50 of pregnancy, was embryolethal, but not teratogenic, in cynomolgus monkeys. The present study was conducted to further evaluate the developmental toxicity of DBTCl given to pregnant monkeys on 3 consecutive days during organogenesis. Cynomolgus monkeys were given DBTCl at 7.5?mg/kg body weight/day by nasogastric intubation on days 19–21, 21–23, 24–26, 26–28, 29–31, 31–33, or 34–36 of pregnancy, and the pregnancy outcome was determined on day 100 of pregnancy. Embryonic/fetal loss was observed in 1 female given DBTCl on days 19–21, 2 females given DBTCl on days 24–26, and 1 female given DBTCl on days 34–36. There were no effects of DBTCl on developmental parameters in surviving fetuses, including fetal body weight, crown-rump length, tail length, or placental weight. No external, internal, or skeletal malformations were detected in fetuses in any group. DBTCl did not affect the incidence of fetuses with skeletal variation or skeletal ossification of fetuses. These data confirm our previous findings that DBTCl was embryolethal, but not teratogenic, in cynomolgus monkeys.     

Chaperone proteins involved in troglitazone-induced toxicity in human hepatoma cell lines.

Troglitazone (TRO), an effective thiazolidinedione antidiabetic agent, was reported to produce idiosyncratic hepatotoxic effects in some individuals. In contrast, rosiglitazone (RSG), in the same group of agents, has no significant toxic effects and now is widely used. In this study, human hepatoma (HepG2) cell lines were exposed to various doses of TRO as well as RSG (0, 25, 50, and 75 microM) for 48 h. Cell lysates were separated by two-dimensional electrophoresis, and the gels were stained with coomassie brilliant blue to compare the spot profiles. The greatest protein expression at a MW of 75 kDa and isoelectric point of 5 was specifically increased with TRO treatments of 50 and 75 microM. The spot was identified as a mixture of immunoglobulin heavy chain binding protein (BiP) and, to a lesser extent, protein disulfide isomerase-related protein (PDIrp). Immunoblot analyses showed that the BiP protein was dose-dependently increased by TRO treatment and, to a lower degree, by RSG. These effects were also correlated with the high induction of BiP mRNA by TRO (50 and 75 microM) and the lower induction by RSG. However, both treatments showed no significant effects on PDIrp expression. The toxic effects of TRO in relation to the overexpression of BiP were also demonstrated in HLE cells, another human hepatoma cell line. In HLE cells, the inhibition of BiP expression by small interference RNA rendered cells more susceptible to the toxic effects of TRO. These results suggest that the overexpression of BiP is a defense mechanism of the endoplasmic reticulum in response to TRO-induced toxicity.     

Subchronic toxicity and toxicogenomic evaluation of tamoxifen citrate + bexarotene in female rats.

Tamoxifen (TAM) is a nonsteroidal antiestrogen that prevents estrogen receptor-positive breast cancer in rodents and humans. Bexarotene (BEX), a selective agonist for retinoid X receptors, inhibits mammary carcinogenesis in rodents. The present study was conducted to support the preclinical development of TAM (tamoxifen citrate) + BEX for use in breast cancer chemoprevention, and to investigate the influence of these agents on hepatic gene expression. Female CD rats (20 per group) received daily oral (gavage) exposure to TAM (0 or 60 microg/kg/day) and/or BEX (0, 5, 15, or 45 mg/kg/day) for a minimum of 90 days. BEX induced mild, dose-related anemia and dose-related increases in serum alkaline phosphatase, cholesterol, triglycerides, and calcium levels, and increased platelet counts. TAM had no biologically significant effect on any clinical pathology parameter and did not alter the effects of BEX on these endpoints. Microscopic alterations induced by BEX included epidermal hyperplasia, hyperkeratosis (stomach), and cytoplasmic clearing (liver). Microscopic changes in TAM-treated rats were limited to mucous cell hypertrophy in the cervix and vagina. The toxicity of administration of the combination of TAM + BEX can generally be predicted on the basis of the toxicity of each drug as a single agent. BEX induced dose-related alterations in the expression of several genes involved in steroid, drug, and/or fatty acid metabolism; TAM did not alter these effects of BEX. Differential expression of genes involved in drug and lipid metabolism may underlie the observed effects of BEX on cholesterol and triglyceride levels and its effects on liver histology.     

Disposition of a low dose of bisphenol a in male and female cynomolgus monkeys.

Bisphenol A (BPA) is a weak estrogenic compound mass-produced with potential human exposure. Following a single oral or intravenous (iv) dose of 100 microg/kg [ring-14C(U)] radiolabeled bisphenol A (14C-BPA) to male and female cynomolgus monkeys, 79-86% of the administered radioactivity was excreted in urine over 7 days, and most of the urinary excretion was recovered by 24 h after dosing, a large part of this occurring within 12 h. The fecal excretion of radioactivity over 7 days was minimal (1.8-3.1%). Toxicokinetic parameters obtained from plasma 14C-BPA-derived radioactivity during 48 h were C(max) = 104-107 ng-eq/ml between 0.25 and 2 h, and AUC(oral) = 244-265 ng-eq*h/ml after oral dosing. In the case of the iv dose, AUC(iv) was 377-382 ng-eq*h/ml, and the bioavailability was 0.66-0.70. The terminal elimination half-life was larger post-iv dose (t(1/2iv) = 13.5-14.7 h) than post-oral dose (t(1/2oral) = 9.63-9.80 h). After iv dose, the fast-phase half-life (t(1/2f)) of total radioactivity was 0.61-0.67 h. The t(1/2f) of unchanged 14C-BPA for females (0.39 h) was smaller than that for males (0.57 h). These results suggested the distribution of lipophilic 14C-BPA in adipose tissue after iv dose, in contrast to first pass metabolism after oral dose. 14C-BPA-derived radioactivity was strongly bound to plasma protein (f(p) = 0.055). Radio-HPLC analysis suggested the predominant plasma and urinary metabolites were mono- and diglucuronide of 14C-BPA and unchanged 14C-BPA was very low (< or =1.5%) after oral dose. These results indicate that the intestinal absorption and metabolism of BPA was rapid and extensive, and the major metabolites, glucuronide conjugates of 14C-BPA, were rapidly excreted into urine in monkeys.     

Histopathological studies on the toxicity of ochratoxin A in rats. I. Acute oral toxicity

The acute oral toxicity of ochratoxin A was studied in adult male Wistar rats using single or multiple doses. The oral LD50 was estimated to be 28 mg/kg. The most striking pathologic changes following treatment occurred in the duodenum and jejunum, characterized by severe catarrhal or erosive enteritis which appeared within 4 hr after dosing and subsided within 24 hr. Although near-lethal single doses did not elicit any evidence of renal damage, after several consecutive daily doses, massive acidophilic degeneration with necrosis and desquamation of epithelium occurred in the proximal tubules. Necrosis of cells in germinal centers of the spleen and lymph nodes occurred, indicating a sensitivity of lymphatic tissues to the toxin. Hepatotoxicity was minimal, limited principally to depletion of hepatic glycogen.     

Role of the Kupffer cell in mediating hepatic toxicity and carcinogenesis.

Kupffer cells are resident macrophages of the liver and play an important role in its normal physiology and homeostasis as well as participating in the acute and chronic responses of the liver to toxic compounds. Activation of Kupffer cells directly or indirectly by toxic agents results in the release of an array of inflammatory mediators, growth factors, and reactive oxygen species. This activation appears to modulate acute hepatocyte injury as well as chronic liver responses including hepatic cancer. Understanding the role Kupffer cells play in these diverse responses is key to understanding mechanisms of liver injury. Idiosyncratic drug-induced liver disease results in morbidity and mortality, impacting severely on the development of new pharmacological agents. Modulation of the response of Kupffer cells by drugs has been suggested as a cause for the idiosyncratic response. Similarly, liver damage seen in chronic ethanol consumption appears to be modulated by Kupffer cell activation. More recent evidence has noted a contributory role of Kupffer cell activation in the process of hepatic carcinogenesis. Several nongenotoxic carcinogens, for example, activate Kupffer cells resulting in the release of cytokines and/or reactive oxygen species that induce hepatocyte cell proliferation and may enhance clonal expansion of preneoplastic cells leading to neoplasia. Kupffer cells therefore appear to play a central role in the hepatic response to toxic and carcinogenic agents. Taken together, the data presented in this symposium illustrate to the toxicologist the central role played by Kupffer cells in mediating hepatotoxicity.     

Subchronic studies in Sprague-Dawley rats to investigate mechanisms of MTBE-induced Leydig cell cancer.

High MTBE exposures caused rat Leydig cell (LC) tumors in inhalation and gavage cancer bioassays. Investigating early endocrine changes consistent with known mechanisms of LC carcinogenesis, we gavaged adult male Sprague-Dawley rats with MTBE in five different subchronic experiments and studied testosterone biosynthesis in isolated rat LCs exposed in vitro to MTBE or a major metabolite, t-butanol. In vitro LC testosterone production declined 29-50% following 3-h exposures to 50-100 mM MTBE or t-butanol. Within hours after gavaging with 1,000 or 1,500 mg/kg MTBE, circulating testosterone declined to 38-49% of control (p < 0.05). If sampled longer after treatment or with lower doses, testosterone reductions were less dramatic or nondetectable even after 28 days of treatment. Accessory organ:brain weight ratios decreased only slightly although showing dose response with 40-800 mg/kg/day after 28 days. High MTBE doses caused slight liver weight and total P450 increases. Reduced aromatase activity in liver and testis microsomes predicted low serum estradiol, but estradiol was 19% higher than corn oil controls concurrent with testosterone reduction 1 h after the last of 14 daily 1,200-mg/kg doses (p < 0.05). Pituitary luteinizing hormone (LH) and prolactin measured in both intact and orchiectomized rats, with testosterone implants in some castrated rats providing stable levels of testosterone, revealed no consistent direct effect on hypothalamic-pituitary function. MTBE-treated rat livers showed no evidence of peroxisome proliferation, a characteristic of some LC carcinogens. Considering recognized mechanisms of Leydig cell cancer in rats, collectively these results suggested reduced LC steroidogenesis enzyme activity as a possible mechanism underlying MTBE LC carcinogenesis.     

Toxicological studies on fosfomycin-Na salt. I. Acute toxicity in mice and rats (author's transl)]

The acute toxicity of sodium fosfomycin (FOM-Na), a new antibiotic in ICR mice and Wistar rats has been investigated. The LD50 values in mice were: 1,230 (male), 1,225 (female) mg/kg by i.v.; 2,175 (m), 2,467 (f) mg/kg by i.p.; 2,625 (m), 2,662 (f) mg/kg by i.m.; 5,100 (m), 6,150 (f) mg/kg by s.c. and 8,020 (m), 7,300 (f) mg/kg by p.o. The LD50 values in rats were: 1,650 (m), 1,560 (f) mg/kg by i.v.; 2,060 (m), 2,000 (f) mg/kg by i.p.; 2,630 (m), 2,460 (f) mg/kg by i.m.; 5,100 (m), 4,320 (f) mg/kg by s.c. and 4,700 (m), 4,550 (f) mg/kg by p.o. Animals dosed only i.v. died within 2 minutes. Signs of toxicity in mice or rats given FOM-Na were similar and included motor activity depression, reduced respiration and occasionally tremors. Surviving mice or rats given FOM-Na developed no pathological changes of the drug specificity.     

Toxicological studies on fosfomycin-Na salt. II. Subacute toxicity in rats and rabbits (author's transl)]

FOM-Na solution in distilled water for injection, J.P., with its pH adjusted to 7.0 +/- 0.2 with diluted hydrochloric acid, was administered to rats and rabbits for subacute toxicity test. The results revealed the following: 1. It was intraperitoneally administered to Wistar rats each weighing 100 +/- 10 g at their age of 5 weeks, and intravenously into auricular veins of male albino rabbits each weighing about 3 kg, for 35 successive days except Sundays through one administration per day. There was no death in rats of both sexes with the doses less than 1,000 mg/kg, while 3/10 males and 5/10 females died with the dose of 2,000 mg/kg. In terms of general conditions, both stretched physical position and vocalization were noted, which were presumed to be attributable to the stimuli of the administration. In the postmortem examination mutual adhesion of organs in the peritoneum was noted, while in the lightmicroscopic examinations histological proliferation and adhesion were found out in the hepatic capsules or serous membrane of the intestine etc., but no abnormalities were detected in the other organs. In the mean body weights, there were no significant differences between the control group and the groups of males with doses less than 500 mg/kg and females with doses less than 1,000 mg/kg whereas in the groups of males with doses more than 1,000 mg/kg and the females with a dose of 2,000 mg/kg, a trend of reduced weight gain was noted in comparison with the control group. The feed intake also was reduced as the dose was elevated. In terms of the male group hematology, the In. P increased with doses higher than 250 mg/kg, while BUN was reduced in the groups with a dose of 250 mg/kg and doses higher than 1,000 mg/kg, and Na was reduced in the groups with doses from 125 up to 500 mg/kg. In the female groups, the loss of Hgb and rise in the Cl were noted in the doses higher than 500 mg/kg while the loss of WBC was noted in almost all the treated groups. However, none of these changes was suggestive of specific abnormalities when compared with the photomicroscopic findings and our hematological background data. 2. There were no significant changes in the general conditions of any group of rabbits. Their mean body weights and their mean feed intakes proceeded almost similarly with those of the control group. In the hematological and histopathological tests also, no specific abnormal finding was experienced, which were deemed to be attributable to the administration of FOM-Na.     

Fumonisin B(1) is hepatotoxic and nephrotoxic in milk-fed calves.

Fumonisins are a group of mycotoxins that alter sphingolipid biosynthesis and induce leukoencephalomalacia in horses and pulmonary edema in pigs. Experimental administration of fumonisin induces hepatotoxicity in all species, including cattle, as well as nephrotoxicity in rats, rabbits, and sheep. We investigated the hepatotoxicity and nephrotoxicity of fumonisin B(1) to calves. Ten milk-fed male Holstein calves aged 7 to 14 days were instrumented to obtain blood and urine. Treated calves (n = 5) were administered fumonisin B(1) at 1 mg/kg, iv, daily and controls (n = 5) 10 ml 0.9% NaCl, iv, daily until euthanized on day 7. Fumonisin B(1)-treated calves were lethargic and had decreased appetite from day 4 onward, serum biochemical evidence of severe liver and bile duct injury, and impaired hepatic function. Treated calves also had biochemical evidence of renal injury that functionally involved the proximal convoluted tubules. Sphinganine and sphingosine concentrations in liver, kidney, lung, heart, and skeletal muscle were increased in treated calves. Sphinganine, but not sphingosine, concentration was increased in brains of treated calves. In fumonisin B(1)-treated calves, hepatic lesions were characterized by disorganized hepatic cords, varying severity of hepatocyte apoptosis, hepatocyte proliferation, and proliferation of bile ductular cells. Renal lesions in treated calves consisted of vacuolar change, apoptosis, karyomegaly, and proliferation of proximal renal tubular cells, as well as dilation of proximal renal tubules, which contained cellular debris and protein. This is the first report of fumonisin B(1)-induced renal injury and organ sphingolipid alterations in cattle.