Teratogenicity studies on linuron, malathion, and methoxychlor in rats

Khera, K. S.; Whalen, C.; Trivett, G.

doi:10.1016/0041-008x(78)90107-2

Cited by 67 publications

(15 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The data from the individual pesticide treatment groups is in agreement with the work of other investigators (Khera et al, 1978;Weil et al, 1972). Khera et al (1978) showed that doses as high as 300 mg malathion/kg administered only on d 6-15 of gestation produced no significant effect on maternal weight gain, fetal weights, and the number of implants, live fetuses, or resorption sites per dam. Also, treatment during the entire gestational period with doses as high as 500 mg carbaryl/kg made no significant alteration in the number of implants, live fetuses or resorptions sites per dam (Weil et al, 1972).…”

Section: Discussionsupporting

confidence: 86%

“…This resulted in a reduced number of rats that survived during the first week. Rats fed malathion during their gestation period did not produce any terata (Kimbrough and Gaines, 1968;Khera et al, 1978). Dobbins (1967) noted decreases in fetal weights and increases in resorptions after dams were administered at least 200 mg malathion/kg body weight.…”

Section: Introductionmentioning

confidence: 96%

See 1 more Smart Citation

A teratology study of carbaryl and malathion mixtures in rat

Lechner¹,

Abdel‐Rahman²

1984

Journal of Toxicology and Environmental Health

View full text Add to dashboard Cite

Recently, much controversy has developed in relation to the use of pesticides alone and in mixtures. Mixtures are used as a more efficient method of pest control. Carbaryl and malathion are one of many combinations used today. A limited amount of work has been done with these two pesticides in relation to their teratogenic potential. This study examined the teratological parameters of carbaryl and malathion in combination compared to the effect of the individual insecticides. Formulation grade carbaryl (0, 1, 10, and 100 mg/kg), formulation grade malathion (1 and 50 mg/kg), and a formulation grade mixture of carbaryl/malathion (1/1 and 50/50 mg/kg) were administered daily by gavage for 3 mo prior to and throughout gestation. Dams were sacrificed on d 20 of gestation, and the fetuses were examined for external, skeletal, and visceral malformations. Significant decreases in dam weight gain during pregnancy and a slight decrease in the number of implantations and number of live fetuses per dam were observed with the 100-mg/kg carbaryl group and were further reduced in both combination doses. The combination dose groups showed a significant reduction in placenta weight. No increases were seen in skeletal or visceral anomalies for the individual treatment groups; however, an increase in external hemorrhagic spots was observed with malathion at 50 mg/kg and the high-dosage mixture group.

show abstract

Section: Discussionsupporting

confidence: 86%

Section: Introductionmentioning

confidence: 96%

A teratology study of carbaryl and malathion mixtures in rat

Lechner¹,

Abdel‐Rahman²

1984

Journal of Toxicology and Environmental Health

View full text Add to dashboard Cite

show abstract

“…Kast (1994) indicated that wavy ribs do not seem to be strain-specific in rats, but Wistar rats generally have a higher background incidence of wavy ribs (2-22%) (Khera and McKinley, 1972;Khera et al, 1978;Buttar et al, 1978;Verma and Guna Sherlin, 2001;Favero et al, 2005) than do Sprague-Dawley (SD or CD s ) rats (0-1.5%) (Nishimura et al, 1982;Marathe and Thomas, 1986;Yoshimura and Delatour, 1986;Vorhees, 1987;Morseth and Nakatsu, 1991), although the incidence of wavy ribs may vary among Wistar populations (Nyitray and Druga, 1989). Wistar rats also may be more sensitive than SD rats to the induction of wavy ribs by exogenous exposures, although the data to compare strain effects is limited.…”

Section: Species Concordance and Divergencementioning

confidence: 96%

Interpretation of skeletal variations for human risk assessment: delayed ossification and wavy ribs

Carney

Kimmel²

2007

Birth Defects Research Pt B

View full text Add to dashboard Cite

Delayed (or incomplete) ossification of developing fetal bones and wavy ribs are some of the most common skeletal variations encountered in regulatory guideline developmental toxicity studies. Although they tend to be regarded as minor effects, they can be quite sensitive and consequently may influence the study lowest-observed-adverse-effect levels (LOAELs), and thus, impact classification, labeling, and risk assessment. In this study, we review the underlying mechanisms of these skeletal variations, evaluate different scenarios in which they have been observed, offer guidance for their interpretation, and comment on their use for risk assessment. Both minor delays in ossification and wavy ribs seem to be readily repairable via postnatal skeletal remodeling, are not mechanistically linked to malformation, and often are seen in the presence of maternal or fetal toxicity. As such, these minor variations would not generally be considered adverse in and of themselves but should be interpreted in the context of other maternal and fetal findings, information available on normal skeletogenesis patterns, mode of action of the test agent, and historical control incidence using a weight of evidence approach. Birth Defects Res 80: 473-496, 2007. r 2007

show abstract

“…After exposure from day 6 to 15 of gestation, an increased number of abnormal fetuses was reported Ž . Khera et al, 1978 . Teratogenicity studies are conducted to detect the potential production of fetal abnormalities. Assessment of effects on reproduction include chemical impacts on functions and processes such as lactation, fertility, gonadal function, oestrus cycles, mating behavior, concep-Ž .…”

mentioning

confidence: 99%