Placental Transmission and Foetal Uptake of 14c-Dimethyltubocurarine

I, Kivalo; Saarikoski, Seppo

doi:10.1093/bja/44.6.557

Cited by 22 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The rate of placental transfer is rapid for nonionized, lipidsoluble chemicals of low molecular weight (less than 1,000 daltons) and is largely controlled by placental blood flow (Mihaly and Morgan 1983;Mirkin and Singh 1976). However, charged molecules such as tubocurarine can also enter the fetus (Kivalo andSaarikoski 1972, 1976). Similarily, chemicals highly ionized at normal blood pH, such as the salicylates, readily cross the placenta (Wilson et al 1977).…”

Section: Phase Ii: Data Analysis and Development Of Risk Assessment Amentioning

confidence: 99%

Incorporating children's toxicokinetics into a risk framework.

Ginsberg

Slikker

Bruckner

et al. 2004

Environ Health Perspect

View full text Add to dashboard Cite

Children's responses to environmental toxicants will be affected by the way in which their systems absorb, distribute, metabolize, and excrete chemicals. These toxicokinetic factors vary during development, from in utero where maternal and placental processes play a large role, to the neonate in which emerging metabolism and clearance pathways are key determinants. Toxicokinetic differences between neonates and adults lead to the potential for internal dosimetry differences and increased or decreased risk, depending on the mechanisms for toxicity and clearance of a given chemical. This article raises a number of questions that need to be addressed when conducting a toxicokinetic analysis of in utero or childhood exposures. These questions are organized into a proposed framework for conducting the assessment that involves problem formulation (identification of early life stage toxicokinetic factors and chemical-specific factors that may raise questions/concerns for children); data analysis (development of analytic approach, construction of child/adult or child/animal dosimetry comparisons); and risk characterization (evaluation of how children's toxicokinetic analysis can be used to decrease uncertainties in the risk assessment). The proposed approach provides a range of analytical options, from qualitative to quantitative, for assessing children's dosimetry. Further, it provides background information on a variety of toxicokinetic factors that can vary as a function of developmental stage. For example, the ontology of metabolizing systems is described via reference to pediatric studies involving therapeutic drugs and evidence from in vitro enzyme studies. This type of resource information is intended to help the assessor begin to address the issues raised in this paper.

show abstract

Section: Phase Ii: Data Analysis and Development Of Risk Assessment Amentioning

confidence: 99%

Incorporating children's toxicokinetics into a risk framework.

Ginsberg

Slikker

Bruckner

et al. 2004

Environ Health Perspect

View full text Add to dashboard Cite

show abstract

“…During the first months of pregnancy, the foetal plasma concentration of 14 C-dmtc was approximately one-tenth of the maternal value 20 min after injection (Kivalo and Saarikoski, 1972). The integrity of the drug was confirmed by chromatography.…”

Section: Discussionmentioning

confidence: 83%

“…In an earlier study of placental transmission and foetal uptake of 14 C-dimethyltubocurarine ( 14 C-dmtc) during the first trimester of pregnancy, it was found that 14 C foetal plasma concentration was approximately one-tenth of the maternal value 20 min after the injection of the substance to the mother (Kivalo and Saarikoski, 1972). The result was in agreement with the findings of Elert and Cohen (1962), who reported that the concentration of tubocurarine in the cord plasma taken at Caesarean section was 5-10% of the maternal value 6-10 min after injecting into the mother.…”

mentioning

confidence: 99%

Placental Transfer of 14c-Dimethyltubocurarine During Caesarean Section

KlVALO

Saarikoski

1976

British Journal of Anaesthesia

View full text Add to dashboard Cite

Placental transfer of 14C-dimethyltubocurarine (14C-dmtc) was studied during Caesarean section. Liquid scintillation counting was used for determination of 14C activity from the maternal and foetal blood samples. Paper chromatography was used to confirm the stability of 14C-dmtc. In all cases 14C-dmtc was able to cross the placenta. Detectable amounts of 14C-dmtc were found in umbilical blood 2 min after injection into the mother. Six and 10 min after injection, the 14C concentration in the umbilical blood was 12% of the corresponding maternal value.

show abstract