Embryolethal and teratogenic effects of bromofenofos in rats

Bromofenofos, an organophosphorus anthelmintic, was administered by gavage to rats as a single dose (50 mg/kg) on one of days 6 through 14 of pregnancy. The dams were killed on day 21, and the fetuses were removed, weighed and examined by routine teratological methods. A significant increase in fetal resorptions occurred after administration on days 9 through 13, with a maximum on day 10. Approximately 72% of the implants were resorbed after administration on day 10. Fetal body weights were significantly decreased when dams were treated on day 8 or later. The greatest decrease in fetal body weights was observed on day 10, when the fetuses weighed less than the controls by about 44% on the average. The incidence of fetuses with gross, skeletal and internal malformations was significantly increased on days 8 through 10, on days 8 through 11 and on days 8 and 9, respectively. Although various types of malformations were observed, most of them occurred on day 8, when no significant increase in fetal resorptions did occur. Cleft lip, short tail, brachygnathia, anal atresia, absence of genital tubercle, fused pelvic legs and perineal testicles were seen on day 8 as gross malformations. Skeletal malformations mainly affected the vertebrae and ribs. Major internal malformations on day 8 were hydronephrosis, hydroureter, anophthalmia, cleft palate, agenesis of the bladder and renal agenesis. Anophthalmia and/or microphthalmia were observed on days 8 through 10, with the highest incidence on day 9. To further determine the no-effect levels for embryolethal and teratogenic effects, a single dose of 10, 20, 30 or 40 mg/kg was administered by gavage to rats on days 8 or 10 of pregnancy. The no-effect levels of single oral dose for embryolethal and teratogenic effects were considered to be 40 and 30 mg/kg, respectively.     

Embryolethality of bromofenofos in rats

Bromofenofos, an organophosphorus anthelmintic, was suspended in deionized water and administered once daily to pregnant rats by gastric intubation on days 8 through 15 of pregnancy in doses of 0, 2.5, 5, 10 and 20 mg/kg. The dams were killed on day 21 of pregnancy, and the number of implants, resorptions and live fetuses was counted. All fetuses were weighed and examined by routine teratological methods. As the results showed, this compound was highly embryolethal in the 20 mg/kg group; approx. 91% of the implants were resorbed at this dose level. Although none of the fetuses were externally malformed in any group, the incidence of skeletal and internal malformations was significantly increased in fetuses in the 20 mg/kg group. Skeletal malformations observed at this dose level were bipartite vertebral centra and wavy ribs. Internal malformations involved anophthalmia, hydronephrosis and hypoplasia of the uterus.     

In vivo preliminary investigations of the effects of the benzimidazole anthelmintic drug flubendazole on rat embryos and fetuses

Flubendazole, in a new formulation with high systemic bioavailability, has been proposed as a macrofilaricide against filarial diseases.To investigate embryotoxic activity, the new flubendazole formulation was administered orally to Sprague Dawley rats at 2, 3.46, 6.32 mg/kg/day on gestation day (GD) 9.5 and 10.5. Embryos/fetuses were evaluated on GD 11.5, 12.5 or 20.At 6.32 mg/kg/day (C_max = 0.801 μg/mL after single administration), flubendazole initially induced an arrest of embryonic development followed by a generalized cell death that led to 100% embryolethality by GD 12.5.At 3.46 mg/kg/day (C_max = 0.539 μg/mL after single administration), flubendazole markedly reduced embryonic development by GD 12.5 without causing cell death. On GD 20, 80% of fetuses showed malformations.At 2 mg/kg/day (C_max = 0.389 μg/mL after single administration), it did not interfere with rat embryofetal development.     

硝酸甘油致突变及致畸胎实验研究

本文探讨硝酸甘油对胎儿的致突变及致畸胎作用。结果显示保剂量组淋巴细胞微核率无显著差异,染色体畸变率亦无显著差异。致畸形试验表明,除８．５ｍｇ／ｋｇ组仔鼠身长下降外,其余各组仔鼠身长、体重、囟门宽度均无差异,各剂量组妊娠黄体数１活胎娄、死胎数、着床数、吸收胎数均无显著差异。实验结果证明,硝酸甘油对胎儿无致突变性及致畸胎作用。     

Plasma concentration and placental transfer of bromofenofos in rats

Bromofenofos (BF) was administered by gavage once to non-pregnant and pregnant rats at 50 mg/kg and the plasma concentration-time curves of BF and its metabolite dephosphate bromofenofos (DBF) were determined by high-performance liquid chromatography. DBF reached a peak at 9 h, with 113.4 +/- 5.2 micrograms/ml, followed by a subsequent decline with a plasma half-life of approximately 24 h, but BF was not detected at any time. Next, the concentration of DBF in the conceptus was determined in rats administered BF (50 mg/kg) on day 10 of pregnancy. The concentration in the conceptus did not exceed 30% of that in the maternal plasma at all times, with a maximum of 32.3 +/- 3.3 micrograms/g at 12 h. No BF was detected in maternal plasma. Third, BF (50 mg/kg) was administered to rats on day 15 of pregnancy to determine whether DBF could cross the placenta. The concentration of DBF in the placenta was nearly half that in the maternal plasma at all times. The fetal concentration was approximately 20% of the concentration in the maternal plasma by 24 h. DBF was detected in the amniotic fluid at all times, but the concentration was low, with a maximum of 11.1 +/- 1.4 micrograms/ml at 12 h.     

葛花对大鼠胚胎致畸作用的观察

目的 观察葛花对SD大鼠胚胎的致畸作用.方法 受孕的雌性SD大鼠随机不分为低、中、高剂量组及对照组,称重并编号.大鼠受孕第7 ～16天,以葛花受试物灌胃,第20天处死,分析大鼠胚胎发育指标与胎仔发育指标,观察胎鼠外观和骨骼有无异常.结果 样品各剂量组孕鼠体重、体重增重、子宫连胎重与对照组比较,差异均无统计学意义（P＞0.05）;样品各剂量组活胎率、死胎率、吸收胎率与对照组比较,差异均无统计学意义（P＞0.05）;样品各剂量组胎仔胎盘重、体重、身长、尾长与对照组比较,差异均无统计学意义（P＞0.05）;样品各剂量组胎仔外观畸形率、内脏畸形率、骨骼畸形率与对照组比较,差异均无统计学意义（P＞0.05）.结论 安全剂量的葛花对大鼠无母体毒性、胚胎毒性和致畸作用,人体每天葛花摄入量7.5g,属安全推荐量.     

In vivo and in vitro investigations of the effects of the antimalarial drug dihydroartemisinin (DHA) on rat embryos

Artemisinin derivatives are clinically effective and safe antimalarials, but are not recommended during the first trimester of pregnancy because of the resorptions and abnormalities seen in animal reproduction studies. Understanding how, when and what toxicity occurs is crucial to any assessment of clinical relevance. Previously, DHA has been shown in the rat whole embryo culture (WEC) to primarily affect primitive red blood cells (RBCs) causing subsequent tissue damage and dysmorphogenesis. To verify the primary target of DHA in vivo and to detect consequences induced by early damage on embryo development, pregnant female rats were orally treated on gestation days (GD) 9.5 and 10.5 with 7.5 or 15 mg/kg/day DHA and caesarean sectioned on GD11.5, 12.5, 13.5, 15 and 20. A parallel in vitro WEC study evaluated the role of oxidative damage and examined blood islands and primitive RBCs.

In accordance with the WEC results, primitive RBCs from yolk sac hematopoiesis were the target of DHA in vivo. The resulting anemia led to cell damage, which depending on its degree, was either diffuse or focal. Embryonic response to acute anemia varied from complete recovery to malformation and death, depending on the extent of cell death. Malformations occurred only in litters with embryonic deaths. DHA induced low glutathione levels in RBCs, indicating that oxidative stress may be involved in artemisinin toxicity; effects were extremely rapid, with altered RBCs seen as early as GD10.

In establishing the relevance of these findings to humans, one should consider differences in the development of rodents and humans. While yolk sac hematopoiesis occurs similarly in the two species, early placentation and extent of exposure differ. In particular, early hematopoiesis takes only 7 days in rats (during which RBCs expand in a clonal fashion) compared with 6 weeks in humans; thus the susceptible period in relation to the duration of exposure to an artemisinin-based treatment may be substantially different.     

Prenatal developmental toxicity study of the basic rubber accelerator, 1,3-di-o-tolylguanidine, in rats

Pregnant rats were given 1,3-di-o-tolylguanidine (DTG) by gavage at 0, 10, 20 or 40 mg/kg bw/day on days 6–19 of pregnancy and the pregnancy outcome was determined on day 20 of pregnancy. At 40 mg/kg bw/day, deaths were observed in four out of 24 females. The incidences of females showing mydriasis at 20 and 40 mg/kg bw/day and showing decreased locomotor activity at 40 mg/kg bw/day were significantly increased. Alopecia, bradypnea, prone position and tremor were also observed at 40 mg/kg bw/day. The maternal body weight gain at 20 and 40 mg/kg bw/day and food consumption at 40 mg/kg bw/day were significantly reduced. A significantly decreased weight of the gravid uterus, increased incidence of postimplantation loss, decreased number of live fetuses, and lowered weights of fetuses and placentae were found at 40 mg/kg bw/day. The incidences of the total number of fetuses with external malformations at 40 mg/kg bw/day and with skeletal malformations at 20 and 40 mg/kg bw/day were significantly increased. Significantly higher incidences of fetuses with brachydactyly and short tail and defects of caudal vertebrae, phalanges and metacarpals were observed at 40 mg/kg bw/day. Delayed ossification was also noted at 40 mg/kg bw/day. The data indicate that DTG is teratogenic at maternal toxic doses and the NOAELs of DTG for maternal and developmental toxicity are 10 mg/kg bw/day in rats.     

Dose-response relationship of cadmium embryotoxicity in cultured mouse embryos

Mouse embryos were exposed in vitro to 1.2 to 2.2 μM cadmium, and effects on embryotoxicity were examined after 39 h of culture. Teratogenic responses similar to in vivo were obtained at 1.2 to 2.2 μM with concomitant reduction in embryonic protein, while embryo deaths were increased from 13.8 to 93.3% at 2.0 to 2.2 μM. The response data of both teratogenicity and growth parameters, including embryonic protein, head lenght, crown-rump lenght, somite number, and protein and diameter of yolk sac, were acceptably fitted to a cadmium is a critical parameter in the manifestation of teratogenic potential, (b) as an estimation of interference in the growth of embryos, embryonic protein is one of the most sensitive endpoints while somite number is an insensitive criterion, and (c) a linear log-probit regression is applicable to the analyses of embryotoxicity data, including growth parameters in whole-embryo culture systems.     

抗生素89－07的胚胎毒和致畸研究

于ＳＤ怀孕大鼠的致畸敏感期（怀孕６～１５ｄ）抗生素８９—０７２０、４０和８０ｍｇ／（ｋｇ·ｄ）ｉｖ连续１０ｄ，实验结果表明母鼠毒性症状出现在８０和４０ｍｇ组，主要表现为母鼠在给药的１～４ｄ（怀孕的６～９ｄ）其平均体重增长低于对照组（Ｐ＜０。０５）且８０ｍｇ组有１只母鼠死亡，７只母鼠呼吸急促，步态异常。但各剂量组均未见有胎仔生长迟缓，外形异常，内脏组织及骨骼检查变异等症状。因此抗生素８９－０７是不具有发育毒性的药物。     

Embryo-lethal and teratogenic effect of the new platinum compound DPR in pregnant mice

Embryo-lethal and teratogenic effects caused by the cisplatin–procaine complex cis-diaminechloro-[2-(diethylamino) ethyl 4-amino-benzoate, N⁴]-chlorideplatinum(II) monohydrochloride monohydrate (DPR) were examined in CD-1 mice after a single administration of 7, 14, 21 or 28 mg/kg, injected on day 6, 9, 13 or 16 of pregnancy. At day 18 of pregnancy fetuses were removed and carefully examined for external, visceral and skeletal malformations under a dissecting microscope. A significant reduction of maternal weight gain was observed in pregnant mice after the administration of 21 (day 13) or 28 mg/kg (days 9 and 13) DPR. The exposure to DPR during the organogenesis and early histogenesis periods of prenatal development (administration on day 9 or 13) induced a significant reduction of the mean percentage of live fetuses and a significant increase of the mean percentage of dead and resorbed fetuses. A dose-dependent reduction of fetal body weight was observed in surviving specimens exposed to DPR on embryonic day 9, 13 or 16. The analysis of surviving fetuses killed on day 18 of gestation showed that a few, but statistically significant, external malformations and visceral anomalies were observed after administration of 21 or 28 mg/kg DPR on embryonic day 13. External malformations consisted of three hepato-omphalocele and six palatoschisis (one random palatoschisis was also observed at 21 mg/kg DPR given on day 9), while visceral anomalies included only renal pelvis dilatation. Skeletal anomalies affected fetuses independently of the day of treatment and were more frequent at the highest doses of DPR. They consisted of a delay in skull ossifications, vertebral and sternal anomalies, and formation of extra ribs. A low and non-significant incidence of skeletal malformations (assymetric sternum) was noticed in fetuses. Our data demonstrated that DPR can cause embryotoxic effects if administered during the period of organogenesis and early histogenesis. Beside embryo-lethality, DPR induced growth retardation and malformations in surviving fetuses.     

Teratogenic effects of nitroimidazopyridazine on the CNS in fetal Wistar (WU) rats

Teratogenic effects caused by a new nitroimidazopyridazine were examined in Wistar (WU) rats after repeated oral administration of 0, 2.5, 10, and 40 mg/kg, given on days 6–17 post coitum (p.c.) (Day of mating = Day 0) in a regular study on embryo-fetal development according to ICH S5A. At day 20 p.c., fetuses were removed and carefully examined under a dissecting microscope for external, visceral and skeletal malformations. The exposure to the high dose of the test compound during the organogenesis and early histogenesis periods of prenatal development induced prominent CNS malformations (exencephaly, neural tube defects (NTD)) associated with external malformations (hyperflexion of the forelimbs). To support the data from this study additional histological evaluation of the brains was performed with the following results: disorganization of the cerebral cortex associated with ectopic subcommissural organs. Additionally, an in vitro test (whole embryo culture, WEC) showed alterations of the developing neural tube after the incubation of rat embryos with the test compound on gestation days 9.5–11.5. Our data demonstrated that nitroimidazopyridazine caused NTDs and limb malformations during organogenesis. Based on these data the further development of the test compound was stopped.     

Developmental and reproductive toxicity evaluation of toluene vapor in the rat II. Developmental toxicity

The developmental toxicity of toluene was evaluated via whole body inhalation exposure, in pregnant Sprague Dawley rats exposed to toluene (99.9% pure) from gestation day (GD) 6–15 inclusive, 6 h/day, at concentrations of 0, 250, 750, 1500 and 3000 ppm (0, 938, 2812, 5625 and 11250 mg/m³). Doses were selected from a preliminary study performed over a range of concentrations from 0 to 5000 ppm, in which maternal and fetal toxicity were observed at 2000 ppm and above. This study has been cited in various regulatory documents and is presented here to allow greater accessibility to results and conclusions.

Toluene induced clinical signs in pregnant dams (ataxia, hyper-responsivity, increased water intake, decreased food consumption) at 3000 ppm, ataxia and hyper-responsivity at 1500 ppm, and reduced maternal body weight gain at 1500 during the exposure period only and at 3000 ppm from initiation of exposure to GD20. At Caesarean section on GD20, no adverse effects on implantation, number and viability of fetuses, or fetal sex distribution were observed. Litter weight and mean fetal weight was reduced at 3000 ppm and mean fetal weight was reduced at 1500 ppm. Instances of reduced or unossified skeletal elements occurred at the same dose levels. Mean fetal weight was also reduced at 250 ppm but not at 750 ppm. Extensive statistical analysis of fetal body weight data support the conclusion that there is no toxicologically significant dose-related effect on fetal body weight at or below 750 ppm. Low incidences (≤2.5%) of various malformations occurred in the 250, 1500, and 3000 ppm groups; there was no increase in the incidence of specific or total malformations with increased exposure and thus these were not attributed to toluene.

In this Toluene study, the maternal toxicity NOAEL was 750 ppm with a defined maternal and developmental toxicity LOAEL of 1500 ppm.     

Comparative behavioral profile of cocaine and norcocaine in rats and monkeys

The effects of cocaine and norcocaine were compared using locomotor activity, fixed-ratio 100 (FR 100) and fixed-interval 4 min (FI 4 min) food reinforcement and free feeding paradigms in rat and intravenous self-administration tests in rhesus monkeys. Cocaine was shown to significantly increase locomotor activity at doses of 20 and 40 mg/kg, while norcocaine had no effect at these doses and produced convulsions and death at 60 and 80 mg/kg. Both compounds significantly reduced food consumption at one or more of the doses tested. Cocaine and norcocaine at doses of 20 and 40 mg/kg, produced decreases in FR responding. Cocaine at doses of 10, 20, and 40 mg/kg, produced increases in FI responding; norcocaine had no effect following 10 mg/kg and decreased responding at 20 and 40 mg/kg. Cocaine (0.2 mg/kg/inj) and norcocaine (0.5, 0.2, 0.8 mg/kg/inj) maintained intravenous self-administration in all three monkeys tested. The data indicate that norcocaine is a pharmacologically active metabolite of cocaine which could account for some of the activity heretofore attributed to cocaine. However, the lack of any stimulatory effect of norcocaine or locomotor activity and the lack of increased responding produced by norcocaine on fixed-interval behavior suggest that norcocaine differs qualitatively from cocaine.     

Toxicity of artemisinin [Artemisia annua L.] in two different periods of pregnancy in Wistar rats

Artemisinin compounds are important for treating multidrug-resistant malaria; however, the possible resorption and abnormalities observed in animal reproduction studies may contraindicate artemisinin use during the first trimester. To evaluate whether artemisinin interferes with developmental outcomes at different periods of pregnancy, Wistar rats were treated by gavage with increasing doses of 7, 35 and 70 mg/kg/day from gestational day [GD] 7 to 13 or 14 to 20. Viable embryos and post-implantation losses, and progestagens and testosterone levels, were monitored in the former treatment group and pregnancy and outcomes data, post-implantation losses and male and female developmental endpoints of the offspring were evaluated in the latter treatment group. Results indicate toxicity for both periods of treatment, with lower sensitivity at later stages of pregnancy. The results showed that dosing with 35 or 75 mg/kg of artemisinin caused high percentages of post-implantation losses that correlated with a trend to lower maternal progestagens and a significant maternal testosterone decrease. These findings demonstrate that oral administration of artemisinin can adversely effect post-implantation development and pregnancy in the rat.     

The effect of imipramine administered before and during pregnancy on litter size in the rat

Previous studies have suggested that anti-depressants administered during pregnancy result in an increase in foetal and neonatal morbidity. The present study examined the effects of the anti-depressant imipramine administered before and during pregnancy on litter size in the rat. Imipramine was found to cause a significant reduction in litter size with doses that are used therapeutically.The authors wish to express their thanks to Ciba-Geigy (Australia) Ltd. for supplying imipramine.     

栗酮对动脉粥样硬化大鼠的治疗作用

目的：观察栗酮对动脉粥样硬化大鼠的治疗作用。方法：采用高脂饲料喂养的方法诱发大鼠动脉粥样硬化模型。造模8周后,选取造模成功大鼠50只随机分为栗酮300、150、75mg/kg剂量组、阳性组（非诺贝特）、模型对照组,每组10只,连续灌胃给药60d,模型对照组给予等体积的蒸馏水,给药同时仍采取高脂饲料喂养。另取10只大鼠为正常对照组,灌胃给予蒸馏水,正常饲料喂养。60d后分别采血检测血清总胆固醇（CHOL）、TG、高密度脂蛋白胆固醇（HDL-C）、低密度脂蛋白胆固醇（LDL-C）、氧化型低密度脂蛋白（Ox-LDL）及取胸主动脉内皮细胞观察细胞凋亡情况,同时取主动脉作病理形态学观察。结果：大鼠连续给栗酮（300mg/kg、150mg/kg）60d血清CHOL、TG、LDL-C、Ox-LDL、细胞凋亡比率较模型对照组明显减低（P〈0.05）,300mg/kg、150mg/kg剂量组大鼠主动脉壁泡沫细胞数目及弹性纤维损伤等病变明显较高脂模型组减轻。结论：栗酮具有明显的降脂及抗动脉壁损伤的作用。     

大蒜油对大鼠实验性脂肪肝的预防作用

目的观察大蒜油对长期喂食高脂饲料引起的大鼠脂肪肝的预防作用。方法于实验第一天一次性注射小剂量四氯化碳并长期喂食高脂饲料复制大鼠脂肪肝模型,大蒜油低、中、高组分别灌胃相应浓度大蒜油,正常对照组、模型组同时灌胃等体积蒸馏水、玉米油,1次/d,连续8周,测定血脂和肝脂,以肝脏的重量、肝脂质含量和肝细胞的脂变程度为主要衡量指标,观察大蒜油预防脂肪肝效果。结果大蒜油各组与模型组相比,肝组织中三酰甘油(TG)、总胆固醇(TC)、游离脂肪酸(FFA)、血清中的葡萄糖(GLU)、TC、TG、FFA、低密度脂蛋白(LDL)含量和谷丙转氨酶(ALT)活力显著降低,病理检查苏丹Ⅲ染色肝细胞脂变减轻。结论大蒜油对大鼠实验性脂肪肝的形成具有预防作用。     

康舒膏对大鼠烫伤的疗效研究

目的:研究由大黄、白芷、川芎等中药经加工后溶于花生油中而制成的康舒膏对大鼠烫伤的疗效.方法:在烫伤的大鼠背部两侧的四个部位分别涂抹生理盐水、花生油、京万红烫伤膏及康舒膏后观察它们的脱痂时间.结果:康舒膏使烫伤处完全脱痂平均时间为(11.48±0.73)d,京万红烫伤膏(11.51±0.87)d,生理盐水(12.88±1.60)d,花生油(12.44±0.73)d.康舒膏和京万红烫伤膏分别与生理盐水和花生油比较差异均有统计学意义(P＜0.05).结论:康舒膏对大鼠烫伤有良好的治疗作用.     

Teratogenic effects of diphenyl diselenide in Wistar rats

Diphenyl diselenide is an organoselenium compound with potential therapeutic use. The present study evaluates the effects of single maternal subcutaneous injection of 50 and 100 mg/kg diphenyl diselenide [(PhSe)₂] at gestational days (GD) 6, 10 or 17 in Wistar rats. The highest dose of (PhSe)₂ was also administered at GD 7–12. External and internal fetal soft-tissue examination was performed at GD 20. No mortality was observed in fetuses or dams at any (PhSe)₂ treatment group. Neither did exposure to (PhSe)₂ cause significant changes to fetal body weight, organ weight, or fetal size when administered at GD 6–8, 10–12 or 17. Exposure to 100 mg/kg (PhSe)₂ at GD 9 produced significant changes in fetal biometry (crown-rump (CR) length) and body weight. No significant increase in the proportion of fetuses with external visible abnormalities was observed in groups exposed to (PhSe)₂. Skeletal anomalies were observed in fetuses in the GD 9–11 treatment groups and included incomplete ossification of cranial bones, misshapen and incomplete ossification of sternebrae, reduced sternebrae number, wavy and extra ribs, incomplete ossification of fore and hindpaw bones and incomplete ossification of sacral and caudal bones. We conclude that maternal administration of (PhSe)₂ during GD 7–12 led to increased incidences of these skeletal variations or anomalies, but did not cause externally visible malformations in rat fetuses.