Effects of thalidomide on developmental, peri- and postnatal function in female New Zealand white rabbits and offspring.

The present study determined effects of thalidomide on three successive generations of New Zealand White rabbits after oral dosing to F0 maternal rabbits during the later third of gestation (post major organogenesis) and lactation. One hundred and twenty four time-mated F0 rabbits (31/dose) were gavaged with 0, 30, 150, or 500 mg/kg thalidomide from gestation day 18 (DG 18) to lactation day 28 (DP or day postpartum 28) for approximately 42 days. At 6 months, 12 F1 males and 12 F1 females were randomly paired within each dose group and mated. Reproductive evaluation and/or gross necropsy of the thoracic, abdominal, and pelvic viscera was performed on day 29 postpartum (DP 29) for F0 rabbits, on DP 49 for F1 pups not selected for continued evaluation, after completion of mating for F1 rabbits, and on DG 29 for F1 rabbits on continued evaluation of F2 litter. There was no thalidomide-related mortality in F0 and F1 rabbits. One F0 doe at 30 and 150 mg/kg and 2 at 500 mg/kg aborted. Maternal F0 rabbits had reductions in feed consumption but not body weight gain during the gestation and lactation periods for 150 and 500 mg/kg. The numbers of does with stillborn and all pups dying from DP 1-4 was increased at 150 and 500 mg/kg. Mean number of liveborn (litter size) and percentage of live pups were decreased at 500 mg/kg. A significantly increased number of pups died at 150 and 500 mg/kg, resulting in a reduced viability index and decreased litter size. There were some F1 male and female body weight reductions at 150 and 500 mg/kg postweaning with no change in feed consumption. F1 Caesarean-sectioning and litter observations were normal. Fertility of F1 offspring was not affected by maternal doses of thalidomide, but the pregnancy index may have been reduced by the 500 mg/kg maternal thalidomide dose. There was an apparent dose-related increase in splayed limbs in F1 pups. Splaying has been reported in New Zealand White rabbits and may be a recessive trait. The splay could be caused by the nerve and muscle fiber degeneration and skeletal muscle atrophy observed in some pups. It could also be due to the decrease in litter size, resulting in fewer pups per litter for nursing, leading to rapid weight gain and a failure of the pups to support this weight. No F2 fetal gross external alterations were observed. In summary, pregnant rabbits orally dosed with up to 500 mg/kg thalidomide from gestation day 18 to lactation day 28 had increased abortion, changes in some natural delivery and litter parameters, and limb splay in some F1 pups. No gross external changes were observed in F1 and F2 pups.     

Octyl methoxycinnamate: two generation reproduction toxicity in Wistar rats by dietary administration.

Wistar rats continuously received octyl methoxycinnamate (OMC) in the diet through two successive generations at nominal doses of 0, 150, 450 or 1000 mg/kg bw/day. OMC had no adverse effects on estrous cycles, mating behavior, conception, parturition, lactation and weaning, sperm and follicle parameters, macropathology and histopathology of the sexual organs. 1000 mg/kg bw/day reduced parental food consumption and body weight (-14% to -16% in males, -4% to -5% females), increased liver weight, produced hepatic cytoplasmic eosinophilia and erosion/ulceration of glandular stomach mucosa. and led to a slightly decreased implantation rate in the top dose F0 and F1 dams. The high dose F1 and F2 pups had reduced lactation weight gain and organ weights and delayed sexual maturation landmarks. There was no evidence of a selective influence of the test compound on pups' sexual landmarks. The NOAEL (no observed adverse effect level) is 450 mg/kg bw/day for fertility and reproductive performance, for systemic parental and developmental toxicity.     

Two-generation reproductive toxicity study of the flame retardant hexabromocyclododecane in rats

Male and female rats were fed a diet containing flame retardant hexabromocyclododecane (HBCD) at 0, 150, 1500 or 15,000 ppm throughout the study beginning at the onset of a 10-week pre-mating period and continuing through the mating, gestation and lactation periods for two generations. The mean daily intakes of HBCD during the whole period of administration were 10.2, 101 and 1008 mg/kg bw in F0 males, 14.0, 141 and 1363 mg/kg bw in F0 females, 11.4, 115 and 1142 mg/kg bw in F1 males, and 14.3, 138 and 1363 mg/kg bw in F1 females for 150, 1500 and 15,000 ppm, respectively. The incidence of rats with decreased thyroid follicles size was increased in F0 and F1 males and females at 1500 ppm and higher. Serum TSH levels were increased in F0 and F1 females at 1500 ppm and higher, and serum T4 levels were decreased in F0 males and females at 15,000 ppm. The number of the primordial follicles in the ovary of F1 females was reduced at 1500 ppm and higher. There were increases in the absolute and relative weights of the liver in male adults and male and female weanlings at 1500 ppm and higher, and in female adults at 15,000 ppm, and of the thyroid in male and female adults at 15,000 ppm. Decreased body weight and body weight gain associated with reduced food consumption were found in F1 males and females at 15,000 ppm. Decreases were found in the viability index of F2 pups and the body weight of male F1 and F2 pups and female F2 pups at 15,000 ppm. In F2 pups, there were low incidences of the completion of eye opening in males at 15,000 ppm and in females at 1500 ppm and higher, and of completed mid-air righting in females at 15,000 ppm. The data indicate that the NOAEL of HBCD in this study was 150 ppm (10.2mg/kg bw/day). The estimated human intake of HBCD is well below the NOAEL in the present study.     

Tetrahydrofuran: two-generation reproduction toxicity in Wistar rats by continuous administration in the drinking water.

In a two-generation reproduction toxicity study, 25 male and 25 female Wistar rats per dose group and generation were exposed continuously to tetrahydrofuran in the drinking water for at least 70 days prior to and during mating, gestation, parturition and lactation to weaning, at concentrations of 0, 1000, 3000 or 9000 ppm (approximately 100, 300 and 700 mg/kg/day in males and females premating, 100, 300 and 800 mg/kg/day in females during gestation, and 200, 500 and 1300 mg/kg/day in females during lactation) through two successive generations. In both generations and sexes, water consumption was dose-relatedly reduced at all doses; food consumption and body weight were reduced at 9000 ppm. Necropsy kidney weights were increased in 9000 ppm F0 males. Pup body weight gain during lactation was reduced in both generations (F1 and F2 pups) and eye opening delayed in the first generation (F1 pups) at 9000 ppm; there were no treatment-related malformations. The NOAEL of tetrahydrofuran in drinking water is 9000 ppm for parental fertility and reproductive performance, and 3000 ppm for systemic parental and developmental toxicity.     

In Utero and Lactational Exposure to Fluoxetine in Wistar Rats: Pregnancy Outcomes and Sexual Development

This study evaluated the reproductive effects of fluoxetine exposure in utero and during lactation on pregnancy outcomes and the sexual development of offspring. Pregnant Wistar rats were treated daily with fluoxetine (0.4, 1.7 and 17 mg/kg/day) or distilled water by gavage from gestation day (GD) 7 to lactation day (LD) 21. A significant reduction in maternal body weight was observed during pregnancy and lactation in dams exposed to 17 mg/kg fluoxetine. Hormone analysis revealed an increase in progestagen and glucocorticoid metabolites on GD 15 and oestrogen and progestagen metabolites on LD 7 in dams treated with 17 mg/kg fluoxetine. Oestrogen metabolites also were increased on LD 7 in dams treated with 0.4 mg/kg fluoxetine. Besides that, an increase in the weight of the adrenal glands and a reduction in uterine weight in dams exposed to highest dose of fluoxetine were observed. Finally, pup birthweight and the viability and weaning indices also were reduced in animals exposed to 17 mg/kg fluoxetine. Overall, maternal hormonal changes were only observed at the highest dose tested, which also induced maternal and foetal toxicity. No significant changes were seen in dams or offspring exposed to therapeutic‐like doses.     

The reproductive toxicology of ammonium perfluorooctanoate (APFO) in the rat

Ammonium perfluorooctanoate (APFO) is a surfactant used primarily as an aid in processing various fluoropolymers. Many toxicology and epidemiological studies have been conducted with APFO; however, no specific information regarding functional reproduction was previously available. Therefore, the potential reproductive toxicity of APFO across two generations of offspring was studied using current EPA OPPTS 870.3800 guidelines. Male and female Sprague-Dawley rats were dosed orally with 0, 1, 3, 10, or 30 mg/kg APFO. Parental (P) generation rats ( approximately 6 weeks old) were dosed at least 70 days prior to mating and until sacrificed (after mating for male rats; after weaning for female rats). F(1)-generation rats were dosed similarly, beginning at weaning. The F(2)-generation pups were maintained through 22 days of lactation. Reproductive parameters evaluated in P- and F(1)-generation rats included estrous cycling, sperm number and quality, mating, fertility, natural delivery, and litter viability and growth. Age at sexual maturation in F(1), anogenital distance in F(2), and presence of nipples (males) in F(2)-generation pups were also determined. Feed consumption, body-weight gain, selected organ-weights, gross pathology and appropriate histopathology were evaluated. Reproductive endpoints including mating, fertility, and natural delivery were not affected in either generation. P- and F(1)-generation male rats showed decreased body weight, and liver and kidney weight increases at all doses. The 30 mg/kg F(1)-generation pups had decreased birth weight. Viability was reduced in the 30 mg/kg F(1)-generation pups in apparent relationship to reduced body weight at birth and weaning; however, F(2)-generation pups at 30 mg/kg, although somewhat lighter, did not show a loss in viability. Preputial separation and vaginal opening were somewhat delayed at 30 mg/kg, but these rats went on to show normal reproductive performance. No-observed-adverse-effect-levels were >30 mg/kg for reproductive function of P- and F(1)-generation rats, 10 mg/kg for F(1)-generation pup mortality, birth weight, and sexual maturation, and less than 1mg/kg for male body-weight and organ-weight changes.     

Reproductive and developmental toxicity screening test of tetrahydrofurfuryl alcohol in rats

Twelve male and female rats per group were given tetrahydrofurfuryl alcohol (THFA) by gavage at 0, 15, 50, 150 or 500 mg/kg/day. Males were dosed for 47 days, beginning 14 days before mating, and females were dosed for 42–52 days beginning 14 days before mating to day 4 of lactation throughout the mating and gestation period. Changes in locomotor activity, inhibition of body weight gain, and/or histopathological changes in the thymus, spleen, testes and/or epididymides were observed in males and females at 150 mg/kg and above. No effects of THFA were found on the copulation index, fertility index, or the number of corpora lutea and implantations in pregnant females. At 500 mg/kg, no pregnant females delivered any pups. At 150 mg/kg, gestation length was prolonged, and the total number of pups born and the number of live pups on postnatal days 0 and 4 was markedly decreased. No effects of THFA were found on the sex ratio and body weight of live pups, or the incidence of pups with malformations or variations. Based on these findings, the NOAELs for parental and reproductive/developmental toxicity of THFA were concluded to be 50 mg/kg/day in rats.     

Chronic toxicity of diethyl phthalate-A three generation lactational and gestational exposure study on male Wistar rats

Diethyl phthalate (DEP) is widely used in the perfume industry as a vehicle for fragrances and in personal care products making human exposure of DEP significant to adults as well as neonatals, as confirmed by levels recorded in blood as well as breast milk samples of human populations in some parts of the world. Therefore, a study was undertaken to understand the toxic effect of DEP over three generations in male Wistar rats. Healthy male and female albino rats of Wistar strain weighing 75–100 g (6–7 weeks old) were randomly assigned to two groups of six each. Group I (Control) male and female rats were fed on normal diet and water ad libitum. Group II (DEP) male and female rats were given DEP dissolved in corn oil mixed with the diet at 50 mg/kg of the diet/day. Hundred days after the treatment, females were mated with males for 10 days. Exposure to DEP was continued throughout mating, gestation until termination at weaning, which was 150 days of total treatment period of the parental generation. The F1 and F2 generation pups were then segregated on the basis of their sex and six male and female pups of both generations were allowed to grow till they were 75–100 g in weight. The treatment was then carried out similar to the parental generation but with reduced dose of 25 mg/kg of the diet/day for F1 generation and 10 mg/kg of the diet/day for F2 generation. Hundred days after the treatment, females were mated with males for 10 days. Exposure to DEP was continued throughout mating, gestation (21 days) until termination at weaning (21 days), which was 150 days of total treatment period of the F1 and F2 generation. Liver and serum ALT, AST and triglycerides were significantly increased over the three generations, which was much more significant in the F2 generation DEP treated group. The serum cholesterol and liver glutathione and glutathione reductase showed a significant decrease over the three generations, which was much more significant in the F2 generation DEP treated group as compared to the parental and F1 generation DEP treated rats. Histology of the liver showed remarkably enhanced fatty degeneration in the F2 generation DEP treated rats as compared to parental and F1 generation DEP treated rats. Vacuolations were much more significant in the F1 generation DEP treated rats as compared to the controls and F2 generation DEP treated rats. It can be concluded from this study, that continuous exposure through food, gestation and lactation over three generation's inspite of dose reduction of DEP leads to an enhanced toxic effect in the latter generations.     

Maternal exposure to triclosan causes fetal development restriction,deregulation of the oestrous cycle,and alters uterine tissue in rat offspring

The aim of the present study was to evaluate the effects of maternal exposure to triclosan (TCS) during pregnancy and lactation on the uterine morphology of rat offspring. For this, 32 Wistar rat dams were distributed into four dose groups (eight mothers per group), and gavage daily, throughout pregnancy and lactation, as follows: Group I–control (GI): corn oil; Group II (GII): TCS diluted in corn oil at a dose of 75 mg/kg/d; Group III (GIII): TCS diluted in corn oil at a dose of 150 mg/kg/d; Group IV (GIV): TCS diluted in corn oil at a dose of 300 mg/kg/d. A female pup of each mother was selected, and at 90 days the pups were euthanized for weighing and collection of the uterus for histomorphometric analysis. The results showed that the mean litter weight was minor in all the groups treated with TCS, when compared with control. The levels thyroid hormones thyroxine (T4) and triiodothyronine (T3) in TCS mother rats were reduced; however the levels of thyroid stimulating hormone (TSH) were increases. The offspring of all groups exposed to TCS presented deregulation of the estrous cycle, compared with control. Analysis of the uterine histological structure demonstrated that all layers of the uterus were affected by the administration of TCS, and the morphometric analysis showed increased uterine layers thickness in the treated groups. We concluded that maternal exposure to TCS during pregnancy and lactation causes intrauterine development restriction, deregulation of the oestrous cycle, and alters uterine tissue in rat offspring.     

Fertility and Perinatal/Postnatal Studies in Rats with the Angiotensin-Converting Enzyme Inhibitor, Quinapril

Fertility and Perinatal/Postnatal Studies in Rats with the Angiotensin-ConvertingEnzyme Inhibitor, Quinapril. DOSTAL, L. A., KIM, S-N., SCHARDEIN,J. L., AND ANDERSON, J. A. (1991). Fundam. Appl. Toxicol. 17,684–695. Quinapril, an inhibitor of angiotensin-convertingenzyme (ACE) and an antihypertensive agent, was evaluated inrats for effects on fertility, reproduction, and perinatal andpostnatal development In a fertility study, male rats were treatedby gavage for 60 days prior to and during mating and femalerats were treated by gavage for 14 days prior to mating, duringmating and gestation, and during lactation with doses of 0,10, 50, or 100 mg quinapril/kg body wt There were no significanteffects on body weight, food consumption, fertility indices,fetal development, or neonatal growth, survival, development,behavior, or reproduction. In a perinatal/postnatal study, administrationof quinapril to females at doses of 25, 75, or 150 mg/kg duringlate gestation and lactation had no effects on parturition,lactation, or postnatal development, but a significant decreasein neonatal body weight during the suckling period was observedat all doses. In a subsequent study, female rats were given150 mg/kg during late gestation, lactation, or late gestationand lactation. No adverse effects were seen in the dams or theoffspring, and no reduction in neonatal body weight was observed.Kidneys from pups whose mothers received quinapril during gestationand/or lactation had minimal juxtaglomerular cell hypertrophy,characteristic of treatment with ACE inhibitors. Low levelsof quinaprilat (the major and pharmacologically active metaboliteof quinapril) were detected in fetal blood and in neonatal blood,indicating offspring exposure to quinapril. Milk quinaprilatconcentrations were 3–5% of the plasma concentrations3–5 hr after dosing. These studies demonstrate no adverseeffects of quinapril on fertility, reproduction, or perinataland postnatal development.     

Reproduction study in rats of ginseng extract G115

The effect of ginseng extract G115 on reproductive performance was studied in two generations of Sprague-Dawley rats. Animals of both sexes were fed either control diet or diet supplemented with ginseng extract G115 at dose levels of 1.5, 5 or 15 mg/kg body weight/day. Parameters of reproduction and lactation in the treated groups were comparable to those of the controls for two generations of dams and pups. For F1 males and females, no treatment-related effects were seen in weekly body weights and food consumption, haematological and clinical chemical data, and ophthalmic, gross and histopathological examinations. The gross autopsies of F0 and F2 animals also revealed no significant treatment-related findings.     

Copper-carbohydrate interaction in maternal, fetal and neonate rat

The present study was undertaken to determine whether the same type of interaction between dietary fructose and copper that affects young growing male rats also affects the fetus and the neonate. Female rats were fed copper-deficient (0.6 μg Cu/g) or adequate (6.0 μg/g) diets containing 62% carbohydrate as fructose or starch either for 8 weeks prior to conception, and during mating, gestation and lactation, or just during gestation. Fetuses were killed at days 14, 18 or 21 of gestation and newborn pups were killed at days 0, 10, or 21 postpartum. Regardless of the duration of dietary copper deprivation, feeding the fructose diet deficient in copper during pregnancy resulted in either fetal resorption or mortality of all newborn pups during the first few hours postpartum. In contrast, copper-deficient rats fed the starch-containing diets delivered live pups. However, 40% of their pups died during the first 2 days postpartum and occurred only when dams had been fed the deficient diet for 12–13 weeks. When fed the deficient diet for a total of 3 weeks only, during pregnancy, all copper-deficient rats fed starch delivered live pups and no mortality occurred during the lactation period. Feeding the copper-adequate fructose diet during lactation resulted in a lower hepatic copper concentration of suckling pups compared with starch feeding. Female pups had higher levels of copper and iron than male pups. The data show that fetal resorption and mortality of the neonate pup was dependent on the type of dietary carbohydrate fed to copper-deficient animals during pregnancy.     

Reproductive and developmental toxicity studies on cefepime dihydrochloride administered subcutaneously to rats during the premating, gestation and lactation periods]

Cefepime dihydrochloride (CFPM) was administered subcutaneously daily at doses of 0, 150, 500 and 1,000 mg/kg for 63 days prior to mating and during mating to male Crj: CD (SD) rats and for 14 days prior to mating and during mating, as well as periods of gestation and lactation to female SD rats. Saline and L-arginine hydrochloride (L-arginine) were used as control articles. Daily doses of test and control articles were equally divided and administered twice a day (b.i.d.). The results obtained are summarized as follows: 1. Soft stool was observed for both male and female F0 rats at CFPM 1,000 mg/kg at the first week of administration period. Further, depilation of injection sites was found in 7 males and 12 females at the same dose level. 2. Body weight gains were suppressed in male F0 rats from Day 28 to 63 of administration period at CFPM 1,000 mg/kg. Moreover, food consumption was reduced in F0 female rats during the first week of administration period at all dose levels of CFPM. 3. CFPM failed to affect the reproductive performance in both male and female F0 rats. 4. Kidney weights were increased in both male and female F0 rats and adrenal weights were augmented in male F0 rats at CFPM 1,000 mg/kg. On the other hand, cecal enlargement were observed for F0 dams treated with CFPM. However, these changes were not considered to be unique to this drug, because they have been described with most antibiotics in this species and appears to be results of modifications in gut flora. 5. Prenatal developments in F1 fetuses were not affected by CFPM. 6. CFPM failed to affect delivery status of F0 dams or survival and lactation indices in F1 pups. 7. CFPM did not affect postnatal differentiations, developmental behaviors, learning ability and memory, spontaneous motor activity or emotionality in F1 rats. 8. Body weight gains and food consumption in both male and female F1 rats were not affected by CFPM. 9. CFPM did not alter the organ weights in both male and female F1 rats. 10. There were no significant differences between drug treated animals and controls regarding the reproductive performance and delivery status of F1 rats. 11. Influences on survival indices, body weights and organ weights were not apparently observed for F2 pups even at CFPM 1,000 mg/kg. Based on the reproductive and developmental indices, the no-effect dose level of CFPM under the present experimental condition was estimated to be 1,000 mg/kg/day against dams (F0) and their offspring (F1).     

Combined repeated-dose and reproductive/developmental toxicity screening test of benzene, 1,1′-oxybis-, tetrapropylene derivs. in rats

We have conducted animal toxicity tests of chemicals for a chemical safety program implemented by the Ministry of Economy, Trade and Industry of Japan. Here we conducted a combined repeated-dose and reproductive/developmental toxicity screening test of benzene, 1,1′-oxybis-, tetrapropylene derivs. (BOTD). BOTD was administered to 9-week-old Crl:CD(SD) male and female rats by gavage at 0, 40, 200, or 1000?mg/kg/day. Males were treated for 42 days including mating period. Females were treated for 42–53 days through the premating, mating, pregnancy, and until Day 4 of lactation periods. Increases in prothrombin time and activated partial thromboplastin time values were observed only in males at 200 and 1000?mg/kg/day. Hypertrophy of centrilobular hepatocytes was observed with increased liver weight in both sexes at 200 and 1000?mg/kg/day, but there was no histologic evidence of hepatotoxicity. Diffuse hypertrophy of follicular cells in thyroid glands was observed in females at 200?mg/kg/day and in both sexes at 1000?mg/kg/day, with an increased blood cholesterol level in females at 1000?mg/kg/day. The conception index was decreased for females at 1000?mg/kg/day; and no abnormalities were detected in the reproductive indices of implantation, delivery, or pups’ condition, although a slight increase in the pups’ body weight was noted at birth. Our data indicate a no-observed-adverse-effect level of 40?mg/kg/day for repeated-dose toxicity on the basis of the prolongation of blood coagulating time, and of 200?mg/kg/day for reproductive/developmental toxicity on the basis of the decreased conception index.     

Safety,efficacy and toxicological evaluation of a novel,patented anti-diabetic extract of Trigonella Foenum-Graecum seed extract (Fenfuro)

Safety and anti-diabetic efficacy of a novel, proprietary Trigonella foenum-graecum seed extract [novel fenugreek extract (FE), Fenfuro?, CR0010810) enriched in furostanolic saponins (>60% w/w, HPLC) were assessed. Concerning safety, we undertook studies dealing with acute oral toxicity, 28-d sub-chronic toxicity and Ames’ bacterial reverse mutation assay that revealed no toxicity. Concerning efficacy, we examined beneficial effects of the extract on rats with type 2 diabetes (T2D). Male Sprague–Dawley rats received a high-fat diet for 2 weeks followed by streptozotocin (STZ, 35?mg/kg i.p.) to produce T2D. Seven days post-STZ, rats showing ≥300?mg/dl fasting plasma glucose level (PGL) were included in the study. FE (150- or 450- mg/kg p.o.) and glipizide (5?mg/kg p.o.) were administered once daily for 20?d and then twice daily for another 10?d (total 30?d). Blood samples were collected at 0, 10, 20 and 30?d of treatment and estimated for fasting plasma triglyceride (PTG), total cholesterol and insulin levels. After 30?d, FE and glipizide-treated diabetic animals were treated in combination with or without metformin (100?mg/kg) twice daily for another 10?d. FE did not influence body weight, feed and water intake. FE (150?mg/kg p.o.) reduced PTG levels in T2D rats by 22%, 24.6% and 29% at 10, 20 and 30?d of treatment, respectively, while glipizide (5?mg/kg p.o.) reduced the PTG levels by 57.4%, 46.2% and 39.4% at these time points. FE (450?mg/kg) treatment in STZ-induced diabetic rats produced significant hypoglycemic activity (approximately 31.5%) as compared to insulin (48.2% with 1 U/kg i.p.). FE (150?mg/kg p.o.) and metformin (100?mg/kg p.o.) combined produced significant reduction (20.7%) of PGL in T2D rats. No adverse effects were observed. We conclude after extensive in vitro and in vivo safety and efficacy studies that FE is safe and effective in treating T2D.     

Reproductive toxicity studies in rats with rimexolone, a corticoid ophthalmic suspension.

Rimexolone is a potent anti-inflammatory corticosteroid with a lower potential for elevating intraocular pressure, relative to other ophthalmic steroids, and is indicated for postsurgical inflammation and uveitis. Fertility and peri/postnatal toxicities were evaluated at oral gavage doses of 50, 150 or 500 mg/kg, and developmental toxicity at 100, 500, or 1000 mg/kg. In the fertility study, male rats were treated daily beginning 4 weeks prior to mating and females were treated daily beginning 2 weeks prior to mating, and through gestation day 6. Females were necropsied on gestation day 15 and males were necropsied after 10 weeks of exposure. In males, dose-related reductions in mean body weights, body weight gains, and food consumption occurred in all groups. In the 500 mg/kg females, mean body weights were reduced during gestation, and there was an increase in early resorptions and concomitant decrease in viable fetuses at this level. There were no effects on copulation or fertility indices, or on the number of corpora lutea and implantation sites. The no-observed-effect level (NOEL) for fertility and reproductive effects was 150 mg/kg. In the developmental toxicity study, female rats were treated daily from gestation days 6 through 17, necropsied on gestation day 20 and fetuses were evaluated. Maternal toxicity occurred at 500 and 1000 mg/kg as indicated by reduced maternal body weights and body weight gains. However, there was no indication of a developmental effect on fetuses due to rimexolone. The NOEL was 1000 mg/kg for the developing fetuses. In the peri/postnatal toxicity study, female rats were treated daily from gestation day 6 through lactation day 20 and necropsied. F1 developmental and behavioral parameters were evaluated. Selected F1 animals were mated at 12 weeks, allowed to deliver, and necropsied on lactation day 21. At 500 mg/kg, F0 maternal body weights were reduced during gestation and lactation, and F1 pup weights were reduced during lactation and the growth phase. There were no effects on the F1 fertility or reproductive capabilities, or on F2 developmental parameters. The NOEL for the F0 females and F1 offspring was 150 mg/kg. Together, these studies indicate that, unlike some corticosteroids, rimexolone does not produce developmental or reproductive toxicity in rats.     

Developmental Neurotoxicity Evaluation of Orally Administered Isopropanol in Rats

Isopropanol was administered by gavage to timed-mated rats fromGestation Day (GD) 6 through Postnatal Day (PND) 21. Doses administeredwere 0, 200, 700, or 1200 mg/kg/day in a volume of 5 ml/kg.The dams were allowed to deliver and body weights and food consumptionwere recorded during gestation and lactation. Pups were counted,examined, sexed, and weighed on PND 0, 4, 7, 13, 17, 21, 36,49, and 68. Litters were culled to eight pups (4:4 or 5:3 sexratio) on PND 4 and litters without acceptable numbers of maleand female pups were eliminated from the study. Pups were weanedon PND 22, and two pups from each litter and their dams werekilled. Six of these pups from each dose group were perfusedin Situ for histopatho logical examination of the central andperipheral nervous sys tem. Brains of the remaining pups weredivided into four regions and weighed. Maternal liver and kidneyweights were re corded. Weaned pups were assessed for day oftestes descent or vaginal opening and for motor activity onPNDs 13, 17, 21, 47, and 58; auditory startle on PNDs 22 and60; and active avoidance on PNDs 60–64. These pups wereeuthanized and examined on PND 68. One high-dose dam died onPND 15, but there were no other clinical observations or effectson maternal weight, food consumption, or gestation length. Pupsurvival, weight, sex ratio, and sexual maturation were unaffected.There were no biologically significant findings in the behavioraltests, no changes in organ weights, and no pathological findingsthat could be attributed to isopropanol exposure. In conclusion,there was no evidence of developmental neurotoxicity associatedwith isopropanol exposure as high as 1200 mg/kg/day.     

Effect of caffeine on rat offspring from treated dams

Pregnant Sprague—Dawley rats were given caffeine at 1.0,0.5 and 0.25 g/kg diet during gestation and lactation. At birth, half of the pups from control and treated rats at each dose level were exchanged and cross fostered. Two litters were produced by each animal from each of the experimental groups.Caffeine at dietary concentrations of 0.5 and 0.25 g/kg throughout gestation and lactation had no significant effect on birth weight, litter size or development. There was also no effect at these doses following treatment during either gestation alone, or lactation alone. At 1.0 g/kg there was a slight reduction of birth weight, as well as a trend towards lower weight gain in litters from dams fed the test diet throughout gestation and lactation.     

Reproductive toxicity of MCPA (4-chloro-2-methylphenoxyacetic acid) in the rat

The reproductive effects of the administration of 4-chloro-2-methylphenoxyacetic acid (MCPA) to rats were evaluated through two generations, from prior to mating, throughout mating, to gestation and lactation. MCPA was administered in the diet at doses of 0, 50, 150, or 450 ppm to 25 male and female immature rats (F0 parents) for 10 weeks. F0 parents were then mated to produce a first litter (F1a), retained only until weaning, and were subsequently remated to produce a second litter, F1b. Groups of male and female F1b animals were then dosed as were their parents for 10 weeks postweaning, and the breeding was repeated to produce F2a and F2b animals. The study concluded with the F2b weanlings. MCPA was administered continuously throughout the study. Only minimal, non-treatment-related observations were noted, which included rhinorrhea (in both treated and control animals in the F0 generation) and malocclusion and alopecia (in both the F0 and F1b generations). There were no consistent dose-related effects on reproductive function for parental animals of either sex in either generation. Statistically significant differences were noted in body weights and body weight gains in the 450-ppm dose group for both male and female pups in F2a and F2b. There were no treatment-related macroscopic or microscopic observations noted for any animal in this study. The no-observable-effect level (NOEL) for reproductive function in rats administered MCPA continuously for two successive generations was determined to be 450 ppm (approximately 22 mg/kg/day). The NOEL for general systemic toxicity, based on body weight effects in adult animals in the F1b generation was 150 ppm. The NOEL for effects on the offspring of the F1b generation, manifested as reduced pup weights and pup weight gains was also 150 ppm (approximately 8 mg/kg/day). Based upon the results of this study, MCPA, administered for two generations to Crl:CD(SD)BR Albino rats, is considered not to be a reproductive toxicant.     

Cimetidine Does Not Demasculinize Male Rat Offspring Exposed in Utero

Cimetidine Does Not Demasculinize Male Rat Offspring. Exposedin Utero. WALKER, T. F., BOTT, J. H., and BOND, B. C. (1987).Fundam. Appl. Toxicol. 8, 188–197. Cimetidine has weakantiandrogenic activity in rats, but does not affect fertilityin male rats at daily doses up to 950 mg/kg. Literature reportshave claimed that giving cimetidine to pregnant rats in thedrinking water caused feminization of male pups, small sex organs,low libido, and low serum testosterone. In the present studythese effects were tested by giving large groups of pregnantrats 180 mg/kg/day cimetidine in the drinking water from Day12 of pregnancy until the end of lactation, or a combinationof drinking water and gavage treatment. Estimations includedanogenital distance exactly 24 and 120 h after birth; serumtestosterone at 55 and 110 days of age; mating performance at110 days and (after castration and testosterone implantation)at 143 days; and testis, prostate, and seminal vesicle weightsat 55 and 147–148 days. Maternally administered cimetidinewas completely without effect on all the parameters measuredin the male offspring. Thus, giving cimetidine to pregnant ratsdid not affect the masculinity of their male offspring.