Retention of C60 and C70 fullerenes on reversed-phase high-performance liquid chromatographic stationary phases.

The separation of C60 and C70 fullerenes on four different polysiloxane stationary phases was examined. It was determined that polar solvents can be used as mobile phases effectively for the separation of fullerene molecules. Unlike previously published work, a polymeric octadecyl siloxane (ODS) stationary phase provided higher separation factors for C70/C60 than did monomeric ODS stationary phases or phenyl substituted stationary phases. For example, for a methanol-diethyl ether (50:50, v/v) mobile phase and C60, k' approximately 5.0 separation factors, alpha = 3.3, were achieved with polymeric ODS compared to alpha = 2.2, with a monomeric ODS stationary phase. A linear solvation energy relationship (LSER) was used to model the importance of solvent interactions and stationary phase interaction to solute retention.

Liver microsomal alkoxyphenoxazone O-dealkylases of white Leghorn chickens: response to mixed function oxidase inducers.

1. The cytochrome P-450 substrates, methoxy-, ethoxy-, pentoxy- and benzyloxyphenoxazone were investigated in liver microsomes of phenobarbital- and beta-napththoflavone-induced White Leghorn chickens and compared to the rat mammalian model. 2. Thirty-two-fold increases in benzyloxyphenoxazone O-dealkylase and 27-fold increases in ethoxyphenoxazone O-dealkylase activities were observed in beta-naphthoflavone-treated chickens compared to only an 18-fold increase in ethoxyphenoxazone O-dealkylase activity in beta-naphthoflavone-treated rats. 3. Decreases in pentoxy- and benzyloxyphenoxazone O-dealkylase activities were observed in phenobarbital-treated chickens in contrast to increases of 197-fold in pentoxy- and 98-fold in benzyloxyphenoxazone O-dealkylases in the phenobarbital-treated rats.

The toxicologic investigation of a feed grain contaminated with seeds of the plant species Cassia.

Feed grain suspected of causing death in a group of pigs was evaluated for toxic potential in chickens. The contaminated grain sorghum mixture was examined visually and contained 3.7% Cassia occidentalis and 1.6% Cassia obtusifolia seeds by weight. Thirty-two chicks were fed a sample of this suspect grain sorghum mixture. Chickens receiving the contaminated grain lost weight rapidly, exhibited clinical signs typical of intoxication with Cassia spp., and by day 16 were severely debilitated. Necropsy and histologic and electron microscopic examinations demonstrated a skeletal and cardiac degenerative myopathy consistent with intoxication by Cassia occidentalis. These toxicologic investigations verified the toxic potential of the contaminated sorghum mixture for chickens, and these comparative observations support prior diagnostic efforts implicating Cassia spp. as a cause of illness in swine.

Acute toxicity of 2-thiotriazone in rats.

The acute toxicity of 2-thiotriazone (TTZ) was evaluated in adult and immature rats of both sexes. 2-Thiotriazone produced marked pulmonary toxicity in rats that was both age and sex dependent. TTZ was highly toxic to adult male rats when given as a single dose (oral LD50 = 4.6 mg/kg and ip LD50 = 1.4 mg/kg) with 100% mortality being observed at 10 mg/kg orally and 5 mg/kg intraperitoneally (ip). Female rats were more resistant than males with only 40% mortality at concentrations of 10-100 mg/kg orally. Immature rats (30-40 days of age) of both sexes showed no response when TTZ was administered at concentrations of 10-1000 mg/kg either orally or ip. Gross and histological examination of lung tissue from rats affected by TTZ revealed severe pulmonary edema, effusion, and mottling of the lungs. Significant increases in lung weights were also observed. Studies with diethylmaleate (DEM) and TTZ indicated that DEM pretreatment potentiated the toxic effects of TTZ in adult male, adult female, and immature rats. Lung weights in DEM/TTZ-treated rats were twice that of animals treated with TTZ alone. The results of the present study indicate that TTZ is highly toxic to male rats with the lungs being particularly vulnerable to its effects and that TTZ toxicity is enhanced by DEM pretreatment.

A toxicological investigation of the garden shrub Brunfelsia calcyina var. floribunda (yesterday-today-and-tomorrow) in three species.

Brunfelsia calcyina var. floribunda is an ornamental evergreen shrub found in the United States. A diagnosis of the fatal intoxication of a canine due to consumption of plant material (primarily berries) was made. The significant features of the clinical constellation were similar to those seen with substances interfering with the neurotransmission process, such as lathyrus or strychnine. Necropsy findings on the canine were unrevealing. Toxicologic studies performed on mice and rats with ground shrub material demonstrated that all parts of this plant are toxic, but unequally so. All plant preparations produced signs similar to those of a spinal convulsant. There were no distinguishing gross pathologic or histopathologic findings associated with the toxicoses induced in the laboratory animals with preparations from this plant. The toxic principles from this shrub are water soluble and very stable. The ability of aqueous extracts stored at 4 C to produce the clinical syndrome and subsequent lethality remained unchanged over a period of 4 months. Exposures are not always fatal. They most often occur in the canine and there is a significant hazard for small children.

Comparison of the effects of Sesbania drummondii on the hepatic microsomal monooxygenase systems of chickens and rats.

Sesbania drummondii, a toxic leguminous shrub found throughout the southeastern United States, induces different responses in chicken vs rat hepatic microsomal monooxygenase systems. Groups of 4- to 8-week-old Sprague-Dawley rats and White Leghorn chickens were given extracts of S drummondii by gavage for 3 days. Doses, which were 0.4 and 0.8% of daily body weights, respectively, for the rats and chickens, were adjusted to induce similar clinical lesions in the 2 species. The hepatic microsomal monooxygenase systems of control and treated animals were compared, using cytochrome P-450 content, cytochrome b5 content, NADH- and NADPH-cytochrome c-reductase activity, and 6 cytochrome P-450 mediated enzyme activities. Increases of twofold in the cytochrome P-450 content, NADPH-cytochrome c-reductase, aminopyrine-N-demethylase, aniline hydroxylase, ethoxycoumarin-O-deethylase, and aryl hydrocarbon hydroxylase activities; fourfold in the aldrin epoxidase activity; and 15-fold in the ethoxyresorufin-O-deethylase activity were observed in the S drummondii-treated chickens. In contrast, the treated rats had nearly twofold decreases in these values, suggesting a species-specific effect of S drummondii on microsomal monooxygenase systems, ie, induced with S drummondii.

Simple aliphatic diamines: acute neurotoxicity.

The acute neurotoxicity of a homologous series of diamines (ethylenediamine to 1,6-diaminohexane) was tested by injection into the lateral ventricle of conscious rats, documented as changes in behavior and electroencephalogram (EEG). Three distinct response patterns were seen ranging from prostration and EEG depression, to EEG seizures and convulsions, to a mixture of the patterns. All compounds were acutely lethal after micromole doses.

Toxicity of polycyclic aromatic hydrocarbons. VI. Effects of 1-nitropyrene on serum enzyme levels in rats, and protection against it by beta-naphthoflavone and dimethyl sulfoxide.

Male Sprague-Dawley rats were pretreated i.p. with corn oil or DMSO (1.5 ml/kg/day), or with beta-naphthoflavone (BNF, 40 mg/kg/day) in corn oil or DMSO for 3 days. 1-Nitropyrene (1-NP, 150 mg/kg) in DMSO was injected i.p. 24 hr after pretreatment. A significant increase in the levels of several serum enzymes was seen in rats pretreated with corn oil alone 24 hr after 1-NP injection. The increase in enzyme activities was significantly reduced by a 3-day pretreatment with DMSO or BNF.

Toxicity of aromatic hydrocarbons. VII. Hepatotoxicity of 9-nitrophenanthrene, and protection against it by beta-naphthoflavone.

Male Sprague-Dawley rats were treated with a single i.p. injection of DMSO (3.0 ml/kg) or 9-nitrophenanthrene (9-NP, mg/kg) in DMSO. 9-NP produced a significant elevation of serum aspartate aminotransferase, alanine aminotransferase, sorbitol dehydrogenase, and gamma-glutamyl transpeptidase (GGTP) levels relative to DMSO-injected rats 24 hr after injection. With the exception of GGTP, the increase in enzyme activities induced by 9-NP was significantly reduced by a 3-day pretreatment with beta-naphthoflavone (BNF; 40 mg/kg/day) in DMSO. The effect of 9-NP on GGTP levels was enhanced by BNF pretreatment.

The oxidative metabolism of fenbendazole: a comparative study.

The oxidative metabolism of fenbendazole (FBZ) was studied in hepatic fractions prepared from livers of cattle, sheep, goats, chickens, ducks, turkeys, rats, rabbits and catfish. All species produced the sulfoxide metabolite (oxfendazole; FBZ-SO), and p-hydroxyfenbendazole (FBZ-OH) was produced by all species except sheep. The product of demethoxycarbonylation, fenbendazole amine (FBZ-NH2), was not produced by liver preparations of any species. A fourth metabolite, resulting from the further oxidation of oxfendazole, fenbendazole sulfone (FBZ-SO2), was formed in all species but at highly varying rates. The chicken exhibited the highest overall rate of FBZ metabolism, followed by the duck, goat, sheep, steer, catfish, rat, rabbit, and turkey. Considerable variation was evident among avian species, the duck and turkey produced substantially less of the FBZ-OH and FBZ-SO2 metabolites than the chicken. Catfish liver preparations formed equivalent amounts of metabolite at 25 degrees C and 37 degrees C incubation temperatures. The formation of the sulfone metabolite (FBZ-SO2), however, was practically nonexistent in catfish.

Comparison of hepatic drug metabolizing enzyme activities in several agricultural species.

1. Several pathways of drug metabolizing enzyme activity were measured in hepatic fractions of cattle, sheep, goats, chickens, turkeys, ducks, rabbits and rats. The pathways examined included the O-demethylation of p-nitrophenol, microsomal ester hydrolysis of procaine and glucuronidation of p-nitrophenol, and the cytosolic acetylation of sulfamethazine and sulfation of 2-naphthol. 2. For most enzymatic pathways measured, goats were more similar to sheep (wether) than to cattle (steers). The exception was UDP-glucuronyltransferase activity, which was significantly higher for the goat than for any other species studied. 3. Within the avian subset, the chicken and turkey were usually the most similar species. 4. The activities of arylsulfotransferase isozymes III and IV were particularly low for the duck compared to the chicken and turkey. 5. N-acetyltransferase activity was very high for rabbits and very low for sheep and goats.

Hepatic drug metabolizing enzyme activity in the channel catfish, Ictalurus punctatus.

1. Several pathways of drug metabolizing enzymic activity were measured in hepatic fractions of the channel catfish and rat using model substrates. The pathways examined included the O-demethylation of p-nitroanisole, microsomal ester hydrolysis of procaine and glucuronidation of p-nitrophenol, and the cytosolic acetylation of sulfamethazine and sulfation of 2-naphthol. Catfish liver preparations were incubated at both 25 degrees C and 37 degrees C. 2. The oxidative metabolism of p-nitrophenol was only one-eighth that of the rat at 37 degrees C and one-twelfth that of the rat at 25 degrees C. 3. Procaine ester hydrolysis was negligible in catfish microsomal preparations. 4. At 37 degrees C, p-nitrophenol glucuronidation was equivalent in catfish and rat microsomes. 5. Catfish cytosolic preparations exhibited N-acetyltransferase and arylsulfotransferase nearly comparable to those of the rat. 6. Rates of glucuronidation and sulfation were higher at 37 degrees C than at 25 degrees C in hepatic fractions of catfish.

Comparative drug metabolism and disposition in minor species.

The disposition of fenbendazole (FBZ) was studied in vivo in cattle (steers), goats, chickens, ducks, turkeys and rabbits, and in vitro in hepatic enzyme preparations from cattle, sheep, goats, rabbits, rats, chickens, ducks, turkeys and catfish. The major excretory metabolite when FBZ was administered either iv or po (5 mg/kg) was p-hydroxyfenbendazole (FBZ-OH). The sulfoxide (FBZ-SO) and sulfone (FBZ-SO2) appeared in plasma but were recovered in only trace amounts in urine or feces, and the amine (FBZ-NH2) was a minor metabolite appearing only occasionally in plasma. The greatest species differences were seen among the avian species, and differences in metabolite excretion correlated well with the ability of the species to metabolize the drug (especially to FBZ-OH) in vitro. Other in vitro studies measured the rate of oxidative, hydrolytic, and conjugative (glucuronide, acetate, sulfate) pathways in liver preparations.

3-Methylindole-induced nasal mucosal damage in mice.

3-Methylindole (3MI) damages nasal olfactory epithelium in mice. Lesions were studied histologically from 30 minutes to 28 days after intraperitoneal injection of 400 mg 3MI/kg. Cellular swelling was apparent in olfactory epithelium by 6 hours after injection of 3MI, while respiratory epithelium was normal. Necrosis of olfactory epithelium and subepithelial glands was diffuse by 48 hours. Subsequent ulceration resulted in epithelial hyperplasia, squamous metaplasia, fibroplasia, and ossification. Partially occlusive intranasal fibrous and osseous tissue persisted through 28 days after 3MI injection.

Toxicity of polycyclic aromatic hydrocarbons. V. Protective effect of beta-naphthoflavone against hepatotoxicity induced by diphenaldehyde in rats.

Male Sprague-Dawley rats were treated ip with beta-naphthoflavone (40 mg/kg/day) in corn oil or in DMSO for three days. Diphenaldehyde (90 mg/kg in DMSO) was injected ip 24 hr after pretreatment. The increase in the levels of aspartate aminotransferase, alanine aminotransferase, sorbitol dehydrogenase, gamma glutamyl transpeptidase, and lactate dehydrogenase was significantly lower in rats pretreated with BNF. This suggests that the BNF-induced P-450 isozyme systems have a protective effect against the acute hepatotoxicity of diphenaldehyde.

Toxicity of polycyclic aromatic hydrocarbons. IV. Effects of diphenaldehyde, a major product of ozonized phenanthrene, in rats.

Diphenaldehyde is the major product of phenanthrene ozonized on silica gel. Male Sprague-Dawley rats were treated with a single ip injection of DMSO (3.0 ml/kg) or diphenaldehyde (90 mg/kg) in DMSO. Diphenaldehyde produced significant alterations in levels of serum aspartate aminotransferase, alanine aminotransferase, sorbitol dehydrogenase, gamma-glutamyl transpeptidase, and lactate dehydrogenase relative to DMSO-injected rats 24 hr after injection. These results, as well as gross observations on necropsy, suggest that diphenaldehyde exhibits significant hepatotoxicity.

Toxicity of polycyclic aromatic hydrocarbons. III. Effects of beta-naphthoflavone pretreatment on hepatotoxicity of compounds produced in the ozonation or NO2-nitration of phenanthrene and pyrene in rats.

Male Sprague-Dawley rats were treated ip with beta-naphthoflavone (BNF, 40 mg/kg/day) in dimethylsulfoxide (DMSO, 26.7 mg BNF/ml) for three days. At 24 hr after the pretreatment DMSO (3.0 ml/kg), phenanthrene (150 mg/kg), ozonized or nitrated products of phenanthrene (150 mg/kg), pyrene (150 mg/kg), or ozonized or nitrated products of pyrene (150 mg/kg) were injected ip. Phenanthrene, pyrene, and their ozonized or nitrated products were dissolved in DMSO (50 mg/ml). No increase in the level of aspartate aminotransferase (AST), alanine aminotransferase (ALT) or sorbitol dehydrogenase (SDH) was seen in the pretreated rats 48 hr after the treatment. This is in contrast to what was seen in previous work without the BNF pretreatment. BNF pretreatment induced a small but significant increase in gamma-glutamyl transpeptidase (GGTP) levels. No treatment group receiving BNF differed from another with respect to GGTP. A decrease in lactate dehydrogenase (LDH) levels was noted in the nitro-PAH treatment groups; the same phenomenon was observed earlier in rats treated with nitro-PAH without BNF treatment. These results suggest that the mixed-function oxidase systems specifically induced by BNF have a protective effect against the hepatotoxicity of the oxonized or nitrated products of phenanthrene and pyrene.

Toxicity of polycyclic aromatic hydrocarbons. II. Effect of NO2-nitrated phenanthrene and pyrene on blood chemistry in rats.

Male Sprague-Dawley rats were treated with a single ip injection of dimethyl sulfoxide (DMSO), phenanthrene, nitrated products of phenanthrene, pyrene, or nitrated products of pyrene. Phenanthrene, pyrene and their nitrated products were dissolved in DMSO. Phenanthrene produced a significant elevation of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels relative to DMSO-injected rats 24 hr after injection. Gamma-glutamyl transpeptidase (GGTP) levels were significantly increased for groups treated with phenanthrene when compared with the DMSO group 72 hr after injection. Nitrated products of phenanthrene produced a significant elevation of serum AST, ALT, sorbitol dehydrogenase (SDH), and GGTP levels when compared with groups treated with DMSO and phenanthrene 24 hr after injection. Four of six rats in the nitrated phenanthrene treatment group died between 48 and 72 hr after the injection. Injection of pyrene caused no significant increases in serum enzyme activities. Significant changes in the serum AST, SDH and LDH levels were observed with the nitrated products of pyrene at 24 hr. Only SDH levels were significantly different when pyrene and its nitrated products were compared. No significant differences were detected at 72 hr with the nitrated products of pyrene. As supported by serum chemistry, this study suggests that the products of the reaction of NO2 with two model polynuclear aromatic hydrocarbons (PAH) are hepatotoxic. Both pyrene and phenanthrene form nitrated products that are more toxic than the parent PAH, but the nitrated products of phenanthrene appear to be more toxic than the nitration products of pyrene.