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PubMed2005

Multigeneration reproductive and developmental toxicity study of bar gene inserted into genetically modified potato on rats.

Each specific protein has an individual gene encoding it, and a foreign gene introduced to a plant can be used to synthesize a new protein. The identification of potential reproductive and developmental toxicity from novel proteins produced by genetically modified (GM) crops is a difficult task. A science-based risk assessment is needed in order to use GM crops as a conventional foodstuff. In this study, the specific characteristics of GM food and low-level chronic exposure were examined using a five-generation animal study. In each generation, rats were fed a solid pellet containing 5% GM potato and non-GM potato for 10 wk prior to mating in order to assess the potential reproductive and developmental toxic effects. In the multigeneration animal study, there were no GM potato-related changes in body weight, food consumption, reproductive performance, and organ weight. Polymerase chain reaction (PCR) was carried out using extracted genomic DNA to examine the possibility of gene persistence in the organ tissues after a long-term exposure to low levels of GM feed. In each generation, the gene responsible for bar was not found in any of the reproductive organs of the GM potato-treated male and female rats, and the litter-related indexes did not show any genetically modified organism (GMO)-related changes. The results suggest that genetically modified crops have no adverse effects on the multigeneration reproductive-developmental ability.

Animals↗

PubMedDate not supplied

Developmental toxicity of metal chelating agents.

Chelation therapy is the basis for the treatment of metal poisoning. A number of chelating agents have been widely used since the 1950s. Since these agents can be potentially given to a metal-intoxicated pregnant woman, their intrinsic developmental toxicities are a matter of concern. While the embryo/fetal toxic effects of some chelators have been reported to occur at doses higher than those currently given in the medical treatment of metal poisoning, according to experimental data the potential use of other metal antidotes is controversial. In those cases, the benefits and risks of usage should be carefully weighed. The developmental toxicity of known chelators of clinical interest is presented here. Chelating agents were divided according to the following structurally related categories: polyaminocarboxylic acids, chelators with vicinal -SH groups, beta-mercapto-alpha-aminoacids, hydroxamic acids, ortho-hydroxycarboxylic acids, and miscellaneous agents. Since it has been demonstrated that the teratogenic potential of most chelators is, at least in part, due to induced trace element deficiencies, the advisability of mineral supplements during chelation treatment is also discussed.

Abnormalities, Drug-Induced↗

PubMed1997

Disposition of netobimin, albendazole, and its metabolites in the pregnant rat: developmental toxicity.

Netobimin (NTB), a benzimidazole prodrug with a good anthelmintic spectrum, was administered orally to female rats at a dose of 59.5 mg NTB/kg, to study its pharmacokinetic behavior and the disposition of its most important metabolites, albendazole (ABZ), albendazole sulfoxide (ABZSO), and albendazole sulfone (ABZSO2). ABZ was found in plasma after 6 hr. Peak plasma concentrations (Cmax) and areas under curves (AUC) of ABZSO were eight- and fourfold higher, respectively, than those of ABZSO2. To study NTB disposition in pregnant rats, three different drug doses (50, 59.5, and 70.7 mg/kg) were given. No significant differences were found between plasma concentrations for each metabolite at the three doses studied. Only ABZ concentrations rose slightly as dose increased. ABZ, ABZSO, and ABZSO2 were found in amniotic sacs and embryos at concentrations that were higher than plasma at the same times. The fetuses obtained after administration of each of the doses of NTB were studied to detect developmental toxicity. A significant correlation was found between rate of developmental toxicity and metabolite concentration. ABZSO embryo concentrations could be the main factor accounting for toxicity.

Albendazole↗

PubMed2002

Evaluation of the developmental toxicity of annatto in the rat.

Annatto, a dye extracted from Bixa orellana seeds, is used as a color additive in butter, cheese and in a variety of other foods as well as in drugs and cosmetics. Toxicological data on annatto and on its main carotenoid pigment bixin are still scarce. In this study we evaluated the developmental toxicity of annatto (28% of bixin). Annatto (0, 31.2, 62.5, 125, 250 and 500 mg/kg body weight/day) was given by gavage to Wistar rats on days 6-15 of pregnancy. Ceasarean sections were performed on day 21. Implantations, living and dead fetuses and resorptions were recorded. Fetuses were weighed and examined for externally-visible anomalies. One-third of fetuses from each litter was examined for visceral anomalies by a microsectioning technique. The remaining fetuses were cleared and stained with Alizarin Red S for skeleton evaluation. No adverse effect of annatto on the mothers was noted. No increase in embryolethality and no reduction of fetal body weight were observed among annatto-exposed rats. Annatto did not induce any increase in the incidence of externally-visible, visceral or skeletal anomalies in the exposed offspring. These findings suggest that annatto was neither maternally toxic nor embryotoxic in the rat. Therefore, the no-observed-adverse-effect level (NOAEL) for annatto-induced maternal and developmental toxicity was 500 mg/kg body weight/day or greater (or > or = 140 mg bixin/kg body weight/day) by the oral route.

Abnormalities, Drug-Induced↗

PubMedDate not supplied

Developmental toxicity of dietary zinc deficiency in New Zealand white rabbits.

Chemically induced maternal Zn deficiency has been shown previously to cause terata and increase embryonic loss in rodents. To examine the potential effects of Zn deficiency in the rabbit, a major developmental toxicity test species, rabbit dams were fed an ethylenediamine-tetraacetic acid-washed alfalfa-based Zn-deficient diet (-Zn) or the same diet replete with 80 ppm Zn (control) from Gestation Day (GD) 0 through 20. A third group of animals was pair fed to match the mean daily feed consumption levels of the < 2 ppm Zn group. By GD 7, maternal serum Zn levels of the -Zn dams were decreased 56% and reached a nadir with a 75% decrease of serum Zn by GD 14. Zinc concentrations in the visceral yolk sac and visceral yolk sac-exoceolomic fluid were decreased 30% and 50%, respectively, by GD 11. Although GD 11 embryonic Zn levels were not affected, the embryos from Zn-deficient dams exhibited decreased head length, somite number, and total protein. On GD 28, a significant increase in resorptions/litter was noted in the -Zn group, and the incidence of totally resorbed litters of the -Zn group was greater than laboratory historical control values. No terata were observed in GD 28 fetuses. This study indicates that Zn deficiency occurring during the standard dosing period of guideline rabbit developmental toxicity studies may be associated with a modest increase in resorption rate and a transient inhibition of embryonic growth, but in contrast to rodent species, does not appear to be teratogenic.

Animals↗

PubMed1990

Evaluation of the developmental toxicity of 2,3-dimercapto-1-propanesulfonate (DMPS) in mice. Effect on mineral metabolism.

The sodium salt of 2,3-dimercapto-1-propanesulfonic acid (DMPS), a potent chelating agent used in the treatment of inorganic and organic heavy metal intoxications was evaluated for developmental toxicity in pregnant Swiss mice. DMPS was administered by gavage at doses of 0, 75, 150 and 300 mg/kg per day on gestational days 6-15. Females were evaluated for body weight gain, food consumption, appearance and behavior, survival rates and reproduction data. Cesarean sections were performed on gestation day 18. There were no maternal toxic effects, and no treatment-related changes were recorded in the number of total implants, resorption, the number of live and dead fetuses, fetal body weight or fetal sex distribution data. Gross external, soft tissue and skeletal examination of the DMPS-treated fetuses did not show significant differences at any dose in comparison with the controls. Mineral analysis of maternal and fetal tissues revealed slight effects of DMPS on metabolism of calcium, magnesium, zinc, copper and iron. The results of this study in mice indicate that DMPS is not a developmental toxicant at levels up to 300 mg/kg per day.

Abnormalities, Drug-Induced↗

PubMed1999

Developmental toxicity studies of four fragrances in rats.

Four fragrances, 6-acetyl-1,1,2,4,4,7-hexamethyltetraline (AHTN), 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-gamma-2-ben zopyran (HHCB), musk ketone and musk xylene were tested for developmental toxicity in Sprague-Dawley rats (25/group, 3 groups/fragrance, 2 fragrances/corn oil control). Dosages tested were HHCB: 50, 150, 500 mg/kg per day; AHTN: 5, 15, 50 mg/kg per day; musk ketone: 15, 45, 150 mg/kg per day; musk xylene: 20, 60, 200 mg/kg per day. All dosages tested exceeded multiples of the estimated maximal daily human dermal exposure. Treatment (gavage, 5 ml/kg) occurred on GDs 7-17 and Caesarean-sectioning on GD 20. Based on the results of these studies, none of the four fragrances tested were more toxic in the conceptuses than in the dams. Maternal NOAELs were 50, 5, 15 and 20 mg/kg per day for HHCB, AHTN, musk ketone and musk xylene, respectively (150, 50, 45 and 60 mg/kg per day caused clinical signs and reduced weight gain and feed consumption). Developmental NOAELs were 150, 50, 45 and 200 mg/kg per day for HHCB, AHTN, musk ketone and musk xylene, respectively. No adverse effects on embryo-fetal viability, growth or morphology occurred at the highest dosages of AHTN (50 mg/kg per day) or musk xylene (200 mg/kg per day). Developmental toxicity occurred at the high-dosages of HHCB (axial skeletal malformations at 500 mg/kg per day) and musk ketone (increased postimplantation loss and reduced fetal body weight at 150 mg/kg per day). The results of this study indicate that under conditions of normal use, the tested fragrances do not pose a risk to human conceptuses.

Animals↗

PubMed1998

Prevention of maternal and developmental toxicity in rats via dietary inclusion of common aflatoxin sorbents: potential for hidden risks.

In earlier work, we have reported that a phyllosilicate clay (HSCAS or NovaSil) can tightly and selectively bind the aflatoxins in vitro and in vivo. Since then, a variety of untested clay and zeolitic minerals have been added to poultry and livestock feeds as potential "aflatoxin binders." However, the efficacy and safety of these products have not been determined. A common zeolite that has been frequently added to animal feed is clinoptilolite. Our objectives in this study were twofold: (1) to utilize the pregnant rat as an in vivo model to compare the potential of HSCAS and clinoptilolite to prevent the developmental toxicity of aflatoxin B1 (AfB1), and (2) to determine the effect of these two sorbents on the metabolism and bioavailability of AfB1. Clay and zeolitic minerals (HSCAS or clinoptilolite) were added to the diet at a level of 0.5% (w/w) and fed to pregnant Sprague-Dawley rats throughout pregnancy (i.e., day 0 to 20). Treatment groups (HSCAS or clinoptilolite) alone and in combination with AfB1 were exposed to sorbents in the feed as well as by gavage. Untreated and AfB1 control animals were fed the basal diet without added sorbent. Between gestation days 6 and 13, animals maintained on diets containing sorbent were gavaged with corn oil in combination with an amount of the respective sorbent equivalent to 0.5% of the estimated maximum daily intake of feed. Animals receiving AfB1 were dosed orally (between days 6 and 13) with AfB1 (2 mg/kg body wt) either alone or concomitantly with a similar quantity of the respective sorbent. Evaluations of toxicity were performed on day 20. These included: maternal (mortality, body weights, feed intake, and litter weights), developmental (embryonic resorptions and fetal body weights), and histological (maternal livers and kidneys). Sorbents alone were not toxic; AfB1 alone and with clinoptilolite resulted in significant maternal and developmental toxicity. Animals treated with HSCAS (plus AfB1) were comparable to controls. Importantly, clinoptilolite (plus AfB1) resulted in severe maternal liver lesions (more severe than AfB1 alone), suggesting that this zeolite may interact with dietary components that modulate aflatoxicosis. In metabolism studies, adult male Sprague-Dawley rats, maintained on diets containing 0.5% (w/w) HSCAS or clinoptilolite, were dosed orally with 2.0 mg AfB1/kg body wt. The concentration of the major urinary metabolite (AfM1) was considerably decreased in the presence of HSCAS. These results suggest that the mechanism of protection of AfB1-induced maternal and developmental toxicities in the rat may involve adsorption and reduction of AfB1 bioavailability in vivo. Importantly, this study demonstrates the potential for significant hidden risks associated with the inclusion of nonselective aflatoxin binders in feeds. Aflatoxin sorbents should be rigorously tested individually and thoroughly characterized in vivo, paying particular attention to their effectiveness and safety in sensitive animal models and their potential for deleterious interactions.

Aflatoxin B1↗

PubMed2000

Conduct and interpretation of a dermal developmental toxicity study with KBR 3023 (a prospective insect repellent) in the Sprague-Dawley rat and Himalayan rabbit.

KBR 3023, 1-(1-methyl-propoxycarbonyl)-2-(2-hydroxyethyl)piperidine, a prospective insect repellent being developed by Bayer Corporation, was evaluated for developmental toxicity in the Sprague-Dawley rat and Himalayan rabbit. As the intended human usage of the test compound is topical, the test systems were exposed to the compound via the dermal route. Specifically, the animals were fitted with Elizabethan collars, to reduce the likelihood of oral ingestion, and dermally administered either 0, 50, 200, or 400 mg KBR 3023/kg (rat), and 0, 50, 100, or 200 mg KBR 3023/kg (rabbit) on gestation days 0-19 (rat) and 0-28 (rabbit). Maternal toxicity, as demonstrated by clinical signs and changes in body weight gain and food consumption during gestation, was characterized. Animals were sacrificed on gestation day 20 (rat) and 29 (rabbit), at which time fetuses were removed by cesarean section and a gross maternal necropsy was performed. All fetuses were evaluated for external anomalies. With rats, approximately half of each litter was examined for visceral effects; the other half underwent a skeletal examination. With rabbits, all fetuses underwent both visceral and skeletal examinations. No effects were observed on maternal body weight gain or food consumption in either the rat or rabbit. In the rat, dermal effects (scaling/sloughing), were observed at the dose site of all test substance-treated groups from approximately gestation day 7 until termination of the study. Also noted were an increase in both absolute and relative liver weights in rats in the 400-mg/kg dose group. In the rabbit, dermal effects (slight erythema, squamous and cracked skin) were noted at the dose site of virtually all does administered the test compound, from approximately gestation day 7 until termination. Also observed in the rabbits was a potentially compound-related increase in soft stool, particularly at the highest dose level. In both species, there were no statistically significant effects on any reproductive parameters, or any embryonic endpoints, including pre/post-implantation loss and resorptions. There were no statistically significant effects on litter size or fetal or placental weights. No test compound-related external, visceral, or skeletal findings were observed. No effect on the individual fetal or litter incidence of total malformations or variations was observed and there was no difference in the incidence of malformations between males and females. KBR 3023 Technical, administered as described in these studies, produced maternal effects in the rat (liver weight) at a dose of 400 mg/kg, and in the rabbit (soft stool) in the 200-mg/kg dose group. No developmental toxicity was observed at any dose level.

Administration, Cutaneous↗

PubMed1996

Developmental toxicity of concanavalin A in rats: association with restricted migration of neural crest cells.

Concanavalin A (Con A), a plant lectin, was injected iv into pregnant rats as a single dose of 5, 10 or 20 mg/kg on gestational day (GD) 8, to investigate developmental toxicity in foetuses at term and to examine histologically embryos between GD 10 and 12. There were high incidences of various malformations in the 10 and 20 mg/kg groups: externally, craniofacial dysplasia and closure defects of the ventral body wall; internally, anophthalmia and cardiovascular malformations; and in the skeleton, anomalies of the anterior region of the vertebrae and ribs. Histological examination revealed that neural crest cells (NCC) in the control embryos appeared to be streaming from the neural crest towards the ventral region on GD 10, 11 and 12, and reached the region of the branchial arches on GD 12. By contrast, those in the Con A-treated embryos were aggregated near the dorsal region on GD 10 and 11, and had not reached the destination even on GD 12. These findings suggest that pathogenesis of developmental toxicity of Con A in rats is associated with disturbance of NCC migration and inhibition of their pluripotentiality at the destination.

Abnormalities, Drug-Induced↗

PubMed2004

[Recent TDI derivation of dioxin based on the reproductive and developmental toxicity].

In 1998, WHO-IPCS re-assessed the TDI of dioxin, which was derived from the body burdens of TCDD exposed to the experimental animals. Then, the international assessment agencies and governmental assessment agencies have conducted the dioxin fs health assessment using the similar method to the WHO-IPCS approach. The key endpoints were reproductive and developmental toxicity caused by in utero and lactational exposure. Each assessment agencies used the similar data set of the toxicity studies, however, there are some differences about the TDI derivation method and the selection of adverse endpoints. This report reviewed the recent reproductive and developmental toxicity studies of the dioxins and summarized the health assessment in the international or governmental agencies, and discussed the appropriate TDI derivation.

Animals↗

PubMed1987

Developmental toxicity of dinocap in the mouse is not due to two isomers of the major active ingredients.

Technical-grade dinocap, a complex-mixture fungicide, is teratogenic in the CD-1 mouse, causing cleft palate and otolith defects. In this study we compared the developmental toxicities of 2,4-dinitro-6-(1-methylheptyl)phenyl crotonate and 2,6-dinitro-4-(1-methylheptyl)phenyl crotonate, model isomers of the major active ingredients of technical dinocap, to the known teratogenicity of the technical compound. Individual isomers, both isomers combined, or technical dinocap were administered to pregnant mice on days 7-16 of gestation. Some dams were killed at term and litters were removed, dead fetuses and resorptions were counted, and live fetuses were weighed and preserved in Bodian's fixative for examination for cleft palate. Other treated dams were allowed to give birth: postnatal viability and growth, development of swimming behavior, and otolith formation were evaluated. As in previous studies, technical-grade dinocap caused cleft palate and weight deficits in fetuses at term and increased neonatal mortality and abnormal swimming behavior, torticollis, and deficient otolith formation in surviving pups. Neither of the purified isomers exhibited any developmental toxicity when administered under identical conditions. Thus, it is concluded that these isomers are not the active teratogenic component(s) in technical-grade dinocap.

Animals↗

PubMed2001

Physicochemical and graph theoretical descriptors in developmental toxicity SAR: a comparative study.

Chemical insults to the developing fetus can lead to growth retardation, malformation, death, and functional deficits. The present study seeks to determine if physicochemical and/or graph theoretical parameters can be used to determine a structure-activity relationship (SAR) for developmental toxicity, and if consistency is observed among the selected features. The biological data utilized consists of a diverse series of compounds evaluated within the Chernoff-Kavlock in vivo mouse assay. Physicochemical parameters calculated correspond to electronic, steric, and transport properties. Graph theoretical parameters calculated include the simple, valence, and kappa indices. Both sets of parameters were independently applied to derive SARs in order to compare the quality of the respective models. Multiple random sampling, without replacement, was utilized to obtain ten training/test partitions. Models were built by linear discriminant analysis, decision trees, and neural networks respectively. Comparisons on identical sets of data were carried out to determine if any of the model building procedures had a significant advantage in terms of predictive performance. Furthermore, comparison of the features selected within and across the model building processes led to the determination of model consistency. Our results indicate that consistent features related to developmental toxicity are observed and that both physicochemical and graph theoretical parameters have equal utility.

Animals↗

PubMed1984

Developmental toxicity and psychotoxicity of sodium nitrite in rats.

Sodium nitrite (NaNO2) was fed to male and female rats before and during breeding, to females only during gestation and lactation, and to their offspring after weaning (day 21 after birth) through day 90, at levels of 0, 0.0125, 0.025 or 0.05% (w/w) of the diet. Dams in a fifth group (positive controls) were given 4 mg/kg ip of the anti-mitotic/embryotoxic drug 5-azacytidine on day 16 of gestation. All offspring were reared by their natural dams and were evaluated blind with respect to treatment in a battery of standardized behavioural tests between 3 and 90 days of age. NaNO2 produced no significant reductions in parental body weight or food consumption, though it significantly increased offspring mortality and decreased weight gain at the two highest doses during the preweaning period. Functionally, NaNO2 delayed swimming development and decreased open-field activity. The open-field effect was not linearly dose dependent. In rats killed on day 90 after birth, NaNO2 produced no effects on brain or body weights. 5-Azacytidine produced evidence of substantially greater developmental toxicity than did NaNO2. NaNO2 produced a moderate degree of developmental toxicity, but no evidence was found to suggest that the central nervous system was the target organ for the toxic effects. The inclusion of tests of functional development added useful confirmatory evidence to the overall picture of NaNO2 toxicity.

Aging↗

PubMed1999

A limited developmental toxicity study of pentane by inhalation in the rat.

Pentane (CAS No. 109-66-0) is a widely-used chemical that finds many industrial applications. As part of a program looking at the inhalation toxicity of pentane, we studied the potential effects of the chemical on the developing embryo. This communication reports the findings of a limited study which was used to determine whether a full-scale developmental toxicity study was necessary. Groups of 7 to 8 pregnant rats were exposed by inhalation to pentane, 6 hr/day from gestation days 6 through 15 at concentrations of 0 (control), 1000, 3000 and 10,000 ppm, Maternal body weights, clinical signs and food consumption were measured; foetuses were weighed and examined for gross external development. Skeletal and internal organ evaluations were not performed. There were no effects in either the maternal or fetal rats (at concentrations up to and including 10,000 ppm) that could be associated with pentane exposure. Based on those findings, we did not conduct a full-spectrum developmental toxicity study in rats, but concluded that it is unlikely that the foetus would be adversely affected by pentane exposure.

Administration, Inhalation↗

PubMed1995

Developmental toxicity study in rats treated with the anticonvulsant, ralitoline.

The developmental toxicity of the anticonvulsant compound, ralitoline, was investigated in Sprague-Dawley rats administered oral doses of 0, 15, 60, 120, 180, or 240 mg/kg on days 6 through 15 of gestation. An untreated control group and a vehicle control group pair-fed to the high dose group were included. Maternal and fetal parameters were evaluated on day 21 of gestation. Fetuses were examined for external, visceral, and skeletal malformations and variations. Maternal death occurred at 180 and 240 mg/kg. Dose-dependent decreases in body weight, food consumption, and water consumption were observed at 60 mg/kg and above. Body weight gain during treatment was similar in the pair-fed and 240 mg/kg groups. Dose-related CNS signs (hypoactivity, ataxia, prostration, and/or convulsions) were observed at 60 mg/kg and above. Decreased numbers of live fetuses and increased postimplantation loss were observed in a dose-related manner at 120, 180, and 240 mg/kg while no changes occurred in pair-fed controls. Fetal body weights and placental weights were decreased in pair-fed controls and in the 120, 180, and 240 mg/kg groups. The percent fetuses per litter, and the percent litters with external/visceral malformations, were significantly increased at 120, 180, and 240 mg/kg compared with vehicle and pair-fed controls. Dose-related increases in cardiovascular malformations, specifically of the aortic arch (interrupted, stenotic, extra vessel), were apparent at 120 mg/kg and above. The incidence of skeletal variations was increased at 120 mg/kg and above.(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormalities, Drug-Induced↗

PubMed1989

Inhalation developmental toxicity study of propylene oxide in Fischer 344 rats.

The developmental toxicity potential of propylene oxide (PO) was evaluated in Fischer 344 rats following inhalation exposure. Four groups of 25 mated female rats were exposed to 0, 100, 300, and 500 ppm of PO for 6 hr per day on Gestation Days 6 through 15, inclusive. Cesarean sections were performed on all females on Gestation Day 20 and the fetuses removed for morphological evaluation. Exposure to propylene oxide did not adversely affect survival, appearance, or behavior at any of the exposure levels tested. Maternal body weight gain and food consumption were reduced significantly among the females at the 500 ppm level during the exposure period. No exposure-related effects were noted with respect to maternal water consumption, organ weights, cesarean section, or fetal morphological observations with the sole exception of increased frequency of seventh cervical ribs in fetuses at the maternally toxic exposure level of 500 ppm. In summation, the no-observable-adverse-effect level (NOAEL) of propylene oxide, when administered to Fischer 344 rats via whole-body inhalation exposure, was considered to be 300 ppm.

Administration, Inhalation↗

PubMed1988

Developmental toxicity of cobalt in the rat.

To determine the potential developmental toxicity of cobalt, pregnant Sprague-Dawley rats were given by gavage a daily dose of 0, 25, 50; and 100 mg/kg cobalt(II) chloride on d 6-15 of gestation. Females were sacrificed on d 20. Maternal effects included significant reductions in weight gain and food consumption, particularly at 100 mk/kg.d. Hematocrit, hemoglobin concentration, mean corpuscular volume, mean corpuscular hemoglobin, and reticulocytes were increased significantly in the 100-mg/kg.d group. No treatment-related changes were recorded in the number of corpora lutea, total implants, resorptions, the number of live and dead fetuses, fetal size parameters, or fetal sex distribution data. Increased incidence of stunted fetuses per litter was the only adverse finding at 50 and 100 mg/kg.d group. However, this increase was not statistically significant. Examination of fetuses for gross external abnormalities, skeletal malformations, or ossification variations revealed that cobalt did not produce teratogenicity or significant fetotoxicity in the rat at doses as high as 100 mg/kg.d.

Administration, Oral↗