Effects of sodium nitrite on DRL performance in the rat

Viveiros, Donna M.; Tondat, Lynn Marie

doi:10.1016/0091-3057(78)90327-1

Cited by 4 publications

(1 citation statement)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This information was then used to support the pilot, retrospective cohort portion of the epidemiological work, which sought to determine if high nitrate exposure, and consequent MHG, has long -term consequences in regard to the children's neuropsychological development (Kross et al, 1996 ). The possibility of long -term neurological impacts from nitrite exposure and anoxia first came under scrutiny as a result of studies indicating neurological deficit in children having suffered neurological insults resulting from conditions such as general hypoxias of varying etiology and neurological damage related to radiation therapy early in the development process (Petukhov and Ivanov, 1970;Taylor et al, 1987;Aylward, 1990;Aylward, 1993;Aylward et al, 1989;Viveiros and Tondat, 1978 ). Studies in rats have also indicated that there may be link between prolonged -or high -nitrate exposure and delayed socialization behaviors and neurological excitability (Markel et al, 1989).…”

Section: Introductionmentioning

confidence: 99%

Exposure methodology and findings for dietary nitrate exposures in children of Transylvania, Romania

Zeman

Vlad²,

Kross

2002

J Expo Sci Environ Epidemiol

View full text Add to dashboard Cite

Aims: The primary focus of this exposure assessment work involved developing an exposure model and determining a numerical point estimate of the amount of biologically relevant nitrate / nitrite exposure that occurred for each child in the study. This assessment was done in support of two epidemiological studies. The first study was an epidemiological cohort study ( three cohorts based on nitrate / nitrite exposure ) that explored the relationship between high nitrate / nitrite exposure and neuropsychological development. The second study was a nested case / control study ( cases of methemoglobinemia versus disease -free controls ) that sought to explore the relationship between MHG and various risk factors for the disease. Methods: This work uses both dietary survey and environmental sampling and modeling in order to develop two point estimates of nitrate exposure in milligrams per kilogram per day of nitrite ( the biologically active form of the hemoglobin -oxidizing agent ) for the first 6 months of the child's life ( 2 -months -of -age and 6 -months -of -age point estimates ). Methodologies included proxy interviews of primary caregivers, review of existing medical and environmental sampling and analysis. Results: Exposure to nitrate -nitrogen ( with final calculations converted to the biologically active form of the toxin, nitrite ) was categorized as high, medium, and low as determined from the distribution of the data derived from final exposure calculations at both the 2 -months -of -age point estimate and at the 6 -months -of -age point estimate. These tertiles correspond to !1.5 mg / kg / day nitrite -nitrogen for high -exposure individuals, < 1.5 -!0.1 mg / kg / day for medium -exposure individuals, and < 0.1 mg / kg / day for low -exposure individuals. Analyses illustrate that over 90% of the nitrate exposure occurred through the consumption of liquids ( water ) at the 2 -months -of -age point estimate while at the 6 -months -of -age point estimate, a 10 -fold change in the amount of solid consumables occurred. Conclusions: Final exposure calculations were well differentiated into three tertiles based on a point estimate of average daily intake of nitrite in milligrams per kilogram body weight per day at roughly 2 and 6 months of age. These categories of exposure, based on the exposure model point estimate, correspond well with the exposure estimates as estimated only on the basis of cohort status and their corresponding nitrate / nitrite well water levels. Comparisons of these two sets of data illustrate that following the MHG incident, Cohort II shifted places with Cohort I to become the high -exposure cohort. Further, the predictive ability of the exposure assessment in regard to the outcome of MHG was estimated using a Likelihood Ratio and Pearson's Crosstab analysis. This was performed on the 2 -month -of -age point estimate. Likelihood Ratio and Pearson's chi -square were 39.40 and 33.74, respectively, with a probability of achieving these fits by chance alone of < 0.0001. This indicates clearl...

show abstract

Section: Introductionmentioning

confidence: 99%

Exposure methodology and findings for dietary nitrate exposures in children of Transylvania, Romania

Zeman

Vlad²,

Kross

2002

J Expo Sci Environ Epidemiol

View full text Add to dashboard Cite

show abstract

Acquisition deficits induced by sodium nitrite in rats and mice

et al. 1979

View full text Add to dashboard Cite

Graded doses of sodium nitrite were administered shortly before or immediately after a single training trial in an inhibitory avoidance task. A retention test was given at 24 h (rats) or 72 h (mice) after training. The results indicate that sodium nitrite impairs acquisition of an inhibitory avoidance response in rats and mice. Retention was impaired with doses lower than those required for producing hypoxic effects, as measured by the EEG, methemoglobin levels in the blood, blood pressure, and heart rate. Since hypoxia was not involved, it is likely that the effects were mediated by some direct action of sodium nitrite on the CNS.

show abstract