A Study of the Developmental Toxicity Potential of Pentachlorophenol in the Rat

2001 ◽  
Vol 20 (6) ◽  
pp. 353-362 ◽  
Author(s):  
Bruce K. Bernard ◽  
Alan M. Hoberman

Pentachlorophenol (penta, CAS #87–86–5) is primarily used as a wood preservative. As part of the USEPA pesticide reregistration process, the developmental toxicity (embryo-fetal toxicity and teratogenic potential) of commercially available penta was studied following oral gavage to presumed pregnant female Sprague-Dawley rats (Crl:CD BR VAF/Plus Subdivision F, 83–3). Both study design and penta purity met the requirements of the USEPA. Doses of 0 (corn oil), 10, 30, and 80 mg/kg/day were administered to the rats at concentrations of 0, 2, 6, and 16 mg/ml, respectively from day 6 to day 15 of presumed gestation. The dosage volume was 5 ml/kg, adjusted on each day of dosage based on individual body weights recorded immediately before intubation. The rats were sacrificed on day 20 of presumed gestation and necropsied. The number of corpora lutea in each ovary was recorded. The uterus was examined for pregnancy, number and distribution of implantations, early and late resorptions and live and dead fetuses. Each fetus was weighed, sexed, and examined for gross external, soft tissue and skeletal alterations. The no-observable-adverse-effect-level (NOAEL) for maternal toxicity in rats was determined to be 30 mg/kg/day of penta. The developmental NOAEL for penta in rats was also found to be 30 mg/kg/day. The lowest-observable-adverse-effect-level (LOAEL) for penta developmental toxicity (80 mg/kg/day) was associated with increased resorptions, reduced live litter size and fetal body weights, and caused increased malformations and variations. These NOAELs, derived using USEPA approved study designs, are higher than those previously reported using penta that is no longer commercially available in studies with non-approved experimental designs. Penta should not be identified as a selective developmental toxicant in the rat because adverse effects on development of rat conceptuses occurred only at maternally toxic dosages.

2007 ◽  
Vol 26 (4) ◽  
pp. 365-371 ◽  
Author(s):  
John T. Houpt ◽  
Lee C. B. Crouse ◽  
Richard A. Angerhofer ◽  
Glenn J. Leach ◽  
Gunda Reddy

Thiodiglycol (TG), a hydrolysis product of sulfur mustard (HD), is a potential contaminant of soil and water at certain military sites. To establish developmental toxicity criteria for TG, an oral developmental toxicity study was conducted in Sprague-Dawley rats. Neat thiodiglycol (99.9 %) was administered orally to mated female rats from gestation days (GDs) 5 through 19. The day of positive mating was considered day 0. A pilot study was conducted with TG at dose levels 250, 500, 1000, 2000, or 5000 mg/kg to select suitable doses for the main study. In the main study, three groups of rats (25/group) received TG by gavage at dose levels of 430, 1290, or 3870 mg/kg/day. A fourth group served as a sham control. On day 20 of gestation, all females were euthanized and a cesarean section performed. Litters were examined for soft tissue and skeletal alterations. Maternal toxicity was limited to dams receiving TG at 3870 mg/kg/day. At this dose, body weights and food consumption were reduced during certain periods of gestation. Fetuses derived from those dams exhibited a nonstatistically significant increased incidence of variations when compared to controls. Fetal body weights in the 3870 mg/kg/day group were significantly lower than controls. There was no increased incidence of anomalies when thiodiglycol-treated fetuses were compared to controls. It was concluded that TG did not produce terata. Developmental toxicity (decreased fetal weights and associated delays in development) occurred only at the maternally toxic dose of 3870 mg/kg. It appears that 1290 mg/kg/day could be considered no observed adverse effect level (NOAEL) for oral developmental toxicity. The lowest observed adverse effect level (LOAEL) was 3870 mg/kg for maternal toxicity.


2006 ◽  
Vol 25 (5) ◽  
pp. 423-428 ◽  
Author(s):  
Aurelia Lapczynski ◽  
Daniel A. Isola ◽  
Mildred S. Christian ◽  
Robert M. Diener ◽  
Anne Marie Api

The developmental toxicity of acetyl cedrene (AC), a widely used fragrance ingredient, was evaluated in pregnant Sprague-Dawley rats (25/group). Gavaged dosages of 0 (corn oil), 25, 50, or 100 mg/kg/day were administered on days 7 through 17 of gestation (GDs 7 to 17). First and last day dosing suspensions were analyzed for AC content. All rats were observed daily for viability, clinical signs, abortions, and premature deliveries. Body weights were recorded at frequent intervals. Cesarean-sectioning and necropsy examinations were performed on GD 21. Uteri were examined for number and distribution of implantations, live and dead fetuses, and early and late resorptions. The number of corpora lutea in each ovary was also recorded. Fetuses were weighed and examined for gender and gross external changes and soft tissue or skeletal alterations. Totals of 25, 23, 21, and 24 rats became pregnant in the 0 (control), 25, 50 and 100 mg/kg/day groups, respectively, and analysis of dosage preparations verified that administered dosages reflected calculated dosages ±10%. No deaths or premature deliveries occurred in the study. Clinical signs included excessive salivation, which was attributed to the administration of AC. When compared to controls, significant reductions in feed consumption and body weight gains occurred only at 100 mg/kg/day. Both absolute (g/day) and relative (g/kg/day) feed consumption values were significantly decreased on GDs 7 to 12. Relative values were decreased significantly on GDs 15 to 18. Body weight gains were significantly reduced on GDs 7 to 10. Mean maternal body weights remained significantly lower than controls on GDs 9 to 14, but a marked compensatory increase in feed consumption on GDs 15 to 18 prevented further deterioration in body weight gains. No cesarean-sectioning or litter parameters were affected by dosages of AC and necropsy of the dams after cesarean section did not reveal any gross changes attributable to AC. No gross external, soft tissue, or skeletal fetal alterations (malformations or variations) were attributed by dosages AC. The average number of ossifications sites per fetus per litter did not differ among the groups. Based on these data, maternal and developmental no-observable-adverse-effect levels (NOAELs) of 50 and 100 mg/kg/day, respectively, were established for AC.


2006 ◽  
Vol 25 (2) ◽  
pp. 127-132 ◽  
Author(s):  
Anne Marie Api ◽  
Elise M. Lewis ◽  
Alan M. Hoberman ◽  
Mildred S. Christian ◽  
Robert M. Diener

The developmental toxicity of α-methyl-3,4-methylene-dioxyhydrocinnamic aldehyde (MMDHCA), a widely used fragrance ingredient, was evaluated for developmental toxicity in Sprague-Dawley rats (25/group; cesarean-sectioning identified 21 to 25 pregnant rats/group). Oral dosages of 0 (corn oil), 62, 125, or 250 mg/kg/day were administered by gavage on days 7 through 17 of gestation (GDs 7 through 17). Rats were observed for viability, clinical signs, body weights, and feed consumption. Necropsy and cesarean sectioning occurred on GD 21. Uteri were examined for number and distribution of implantations, live and dead fetuses, and early and late resorptions. Numbers of corpora lutea were also recorded. Fetuses were weighed and examined for gender, gross external changes, and soft tissue or skeletal alterations. Analysis of dosage preparations verified calculated dosages ±10%. No deaths occurred. Excessive salivation occurred in all groups, but the incidence was increased at 250 mg/kg/day. The 250 mg/kg/day dosage also was associated with a significant increase in the incidences of a clear, red or yellow perioral and/or red perivaginal substance and significant reductions in mean feed consumption and body weight gains (11.6% and 7.4%, respectively) during the entire dosage period. No gross changes attributable to MMDHCA were observed at necropsy. Cesarean section or litter parameters, as well as fetal alterations, were not affected by MMDHCA at 250 mg/kg/day or either of the lower dosages tested. Based on these data, maternal and developmental no-observable-effect levels (NOAELs) of 125 and >250 mg/kg/day, respectively, were established for MMDHCA. It is concluded that MMDHCA is not a developmental toxicant in rats under the conditions of this study and dosing regimen.


1990 ◽  
Vol 9 (5) ◽  
pp. 497-506 ◽  
Author(s):  
J. Peter Bercz ◽  
Merrel Robinson ◽  
Lillian Jones ◽  
Norbert P. Page ◽  
Michael J. Parnell ◽  
...  

2,4,6-Trichlorophenol (TCP) has been found in drinking water as a result of its use as a fungicide and due to its inadvertent production in the water purification process. This study was conducted since information on the toxicity from repeated ingestion was inadequate. Male and female Sprague-Dawley rats were gavaged with TCP administered in corn oil (2 ml/kg body weight) for 90 consecutive days at dose levels of 0, 80, 240, and 720 mg/kg per day. Treatment-related effects were observed at the highest dose (720 mg/kg/day) and consisted of salivation, urine stains on the fur, increase in absolute and relative weights of the kidneys, liver, adrenal glands, and testes. At this dose, increases were seen in serum protein, albumin, and alanine aminotransferase (ALT), with a decrease in urinary pH. Some effects observed at 240 mg/kg per day were an increase in the absolute and relative weights of the liver and adrenal glands in females, relative liver weights in males, and an increase in serum albumin in males. No treatment-related effects were observed at 80 mg/kg per day. No mortality or significant effects were observed at any dose level for body weight, food consumption, ophthalmic lesions, hematology, gross pathology, or histopathology. Based on clinical chemistry and organ weight changes, it appears that the liver, kidney, and adrenal glands were target organs for systemic toxicity to TCP in this study, although this was not correlated with histopathology lesions. It was concluded that 240 mg/kg/day represents a lowest observed adverse effect level (LOAEL), although the toxic effects were minimal. The no observed adverse effect level (NOAEL) for subchronic exposure to TCP by the oral route was 80 mg/kg per day.


2002 ◽  
Vol 21 (4) ◽  
pp. 301-318 ◽  
Author(s):  
Bruce K. Bernard ◽  
Alan M. Hoberman ◽  
W. Ray Brown ◽  
Anish K. Ranpuria ◽  
Mildred S. Christian

The potential for pentachlorophenol (penta) to induce general and reproductive/developmental toxicity was evaluated in Crl Sprague-Dawley rats, employing a two-generation reproduction toxicity study. Penta was administered by gavage at doses of 0, 10, 30, and 60 mg/kg/day. In both generations, the parental animals (30/sex/group) were intubated daily for 10 weeks before cohabitation and continuing through cohabitation, gestation, and lactation periods. Intubation of the F1 generation was begun 28 days postpartum. Animals were evaluated daily for mortality and general toxicity (clinical observations, body weights and gains, feed consumption). Organ weights were recorded and histopathological evaluations were made. Specific indices of reproductive function evaluated included estrous cycles, mating and fertility, parturition, lactation, viability, and growth and development of offspring, including sexual maturation, sperm parameters, and numbers of ovarian primordial follicles. All deaths in the parental rats were unrelated to penta. Expected metabolic effects of penta, sporadic increased liver weights associated with hepatocellular centrilob-ular hypertrophy and vacuolation and lipofuscin pigmentation, were evident in the 10-, 30-, and 60-mg/kg/day dose group P1 and F1 animals. Toxicity, in the form of liver pathology (single cell necrosis), reduced body weights and associated reductions in organ weights, and reduced feed consumption were noted in both generations at the 30- and 60-mg/kg/day doses. Developmental toxicity associated with these doses included reduced pup weights and viability. The 60-mg/kg/day dose also resulted in delayed sexual maturation, decreased spermatid counts, small prostates and testes, decreased implantations, reduced fertility, and increased resorptions of embryos. Based on these results, it was concluded that 30 mg/kg/day is the lowest-observable-adverse-effect level (LOAEL) and 10 mg/kg/day is the no-observable-adverse-effect level (NOAEL) for both reproductive and general toxicity. These findings are consistent with results from previously conducted studies wherein reproductive/developmental toxicity was observed only at doses that also induced general toxicity. It differs from previous findings in that the NOAEL for general toxicity is two to three times higher for the more pure product than for products produced and tested previously. In addition, the results did not indicate bioaccu-mulation of penta. Thus, penta did not selectively affect reproduction or development of the offspring of rats at a dose of 10 mg/kg/day, a dose that is 7000 to 20,000 times higher than human exposure.


2001 ◽  
Vol 20 (6) ◽  
pp. 345-352 ◽  
Author(s):  
Bruce K. Bernard ◽  
Anish K. Ranpuria ◽  
Alan M. Hoberman

The potential for developmental toxicity of pentachlorophenol (penta) was studied in New Zealand white rabbits at doses of 0 (corn oil), 7.5, 15, and 30 mg/kg/day administered by gavage on days 6 to 18 of gestation. The rabbits were sacrificed on day 29 of presumed gestation and necropsied. Measurements included number of corpora lutea, pregnancy, number and distribution of implantations, early and late resorptions, live and dead fetuses, fetal weight, gender, and gross external, soft tissue, and skeletal alterations. The mid and high doses reduced maternal body weight gain; the high dose caused transient weight loss and reduced feed consumption. There were no effects on embryofetal development at any of the doses evaluated. Based on these data, the maternal no-observable-adverse-effect level (NOAEL) is 7.5 mg/kg/day, while the developmental NOAEL is 30 mg/kg/day. Penta is not a developmental toxicant in a nonrodent animal model.


2007 ◽  
Vol 26 (3) ◽  
pp. 271-276 ◽  
Author(s):  
Valerie T. Politano ◽  
Elise M. Lewis ◽  
Alan M. Hoberman ◽  
Mildred S. Christian ◽  
Robert M. Diener ◽  
...  

Alpha-iso-methylionone, a widely used fragrance ingredient, was evaluated for developmental toxicity in presumed pregnant Sprague-Dawley rats (25/group). Oral dosages of 0, 3, 10, or 30 mg/kg/day alpha-iso-methylionone in corn oil were administered by gavage on gestational days 7 to 17. The presence of spermatozoa and/or a copulatory plug in situ was designated as gestational day. Rats were observed for viability, clinical signs, body weights, and feed consumption. Caesarean sectioning and necropsy occurred on gestational day 21. Uteri were examined for number and distribution of implantations, live and dead fetuses, and early and late resorptions. Numbers of corpora lutea were also recorded. Fetuses were weighed and examined for gender, gross external changes, and soft tissue or skeletal alterations. No maternal or fetal deaths occurred. No fragrance ingredient–related clinical signs were observed. Feed consumption, body weight gains, gross tissue changes at necropsy, and caesarean section or litter parameters, as well as fetal developmental morphology, were unaffected by dosages of alpha-iso-methylionone as high as 30 mg/kg/day. Based on these data, maternal and developmental no observed adverse effect levels of equal to or greater than 30 mg/kg/day were established for alpha-iso-methylionone. It is concluded that alpha-iso-methylionone is not a developmental toxicant in rats at maternal doses of up to 30 mg/kg/day.


2008 ◽  
Vol 27 (2) ◽  
pp. 183-188 ◽  
Author(s):  
Valerie T Politano ◽  
Elise M Lewis ◽  
Alan M Hoberman ◽  
Mildred S Christian ◽  
Robert M Diener ◽  
...  

The developmental toxicity of linalool, a widely used fragrance ingredient, was evaluated in presumed pregnant Sprague-Dawley rats (25/group). Oral dosages of 0, 250, 500, or 1000 mg/kg/day linalool were administered by gavage on gestational days 7 to 17. The presence of spermatozoa and/or a copulatory plug in situ was designated as gestational day 0. Rats were observed for viability, clinical signs, body weights, and feed consumption. Caesarean sectioning and necropsy occurred on gestational day 21. Uteri were examined for number and distribution of implantations, live and dead fetuses, and early and late resorptions. Numbers of corpora lutea were also recorded. Fetuses were weighed and examined for gender, gross external changes, and soft tissue or skeletal alterations. There were no maternal deaths, clinical signs, or gross lesions that were considered related to linalool. During the dosage period, mean relative feed consumption was significantly reduced by 7% and mean body weight gains were reduced by 11% at 1000 mg/kg/day. During the postdosage period, feed consumption values at 1000 mg/kg/day were significantly higher than vehicle control values, which corresponded to the increase in body weight gains during this period. Caesarean section and litter parameters, as well as fetal alterations, were not affected by linalool at any of the three dosages tested. On the basis of these data, the maternal no observed adverse effect level (NOAEL) of linalool is 500 mg/kg/day, whereas the developmental NOAEL is ≥ 1000 mg/kg/day. It is concluded that linalool is not a developmental toxicant in rats at maternal doses of up to 1000 mg/kg/day.


2008 ◽  
Vol 27 (3) ◽  
pp. 295-300 ◽  
Author(s):  
Valerie T. Politano ◽  
Elise M. Lewis ◽  
Alan M. Hoberman ◽  
Mildred S. Christian ◽  
Robert M. Diener ◽  
...  

Methyl dihydrojasmonate (MDJ) is a widely used fragrance ingredient. MDJ was evaluated for developmental toxicity in presumed pregnant Sprague-Dawley rats (25/group) at oral dosages of 0, 40, 80 or 120 mg/kg/day in corn oil administered on gestational days 7–20. Dams were observed for viability, clinical signs, body weights, and feed consumption. Caesarean-sectioning and necropsy occurred on gestational day 21. Fetuses were weighed and examined for gender, gross external changes, and soft tissue or skeletal alterations. No maternal or fetal deaths occurred. MDJ-related maternal clinical signs included an increased incidence of sparse hair coat and ungroomed appearance at 120 mg/kg/day. Two dams in this group also had tan areas in the liver and a pale spleen. The 120 mg/kg/day dosage also caused reduced mean maternal body weight gains and body weights during the dosage period and reduced absolute and relative maternal feed consumption for the entire dosage period. No Caesarean-sectioning or litter parameters were affected by dosages of MDJ as high as 120 mg/kg/day, although at the highest dosage a tendency toward slightly reduced, but not statistically significant, fetal mean body weight was observed. No fetal gross external, soft tissue or skeletal changes were attributable to dosages of MDJ as high as 120 mg/kg/day. Based on these data, maternal No-Observable-Adverse-Effect-Level (NOAEL) of 80 and developmental NOAEL of equal to or greater than 120 mg/kg/day were established for MDJ. It is concluded that MDJ is not a developmental toxicant in rats under the conditions of this study.


2012 ◽  
Vol 31 (3) ◽  
pp. 250-256 ◽  
Author(s):  
Darol E. Dodd ◽  
Linda J. Pluta ◽  
Mark A. Sochaski ◽  
Kathleen A. Funk ◽  
Russell S. Thomas

Male Sprague-Dawley rats were exposed to 1,2,4-tribromobenzene (TBB) by gavage for 5 days, 2, 4, and 13 weeks at 0, 2.5, 5, 10, 25, or 75 mg/kg per d. There were no TBB exposure-related clinical signs of toxicity or changes in body weight. Liver weight increases were dose and exposure time related and statistically significant at ≥10 mg/kg per d. Incidence and severity of centrilobular cytoplasmic alteration and hepatocyte hypertrophy were dose and time related. The 75 mg/kg per d group had minimally increased mitoses within hepatocytes (5 days only). Hepatocyte vacuolation was observed (13 weeks) and was considered TBB exposure related at ≥25 mg/kg per d. Concentrations of blood TBB increased linearly with dose and at 13 weeks, ranged from 0.5 to 17 µg/mL (2.5-75 mg/kg per d). In conclusion, rats administered TBB doses of 10-75 mg/kg per d for 13 weeks had mild liver effects. A no observed adverse effect level of 5 mg/kg per d was selected based on the statistically significant incidence of hepatocyte hypertrophy at doses ≥10 mg/kg per d.


Sign in / Sign up

Export Citation Format

Share Document