title: The effect of various substituents in ortho position of biphenyls on respiratory burst, intracellular calcium elevation in human granulocytes, and uptake of dopamine into rat brain synaptic vesicles and synaptosomes.
abstract: Polychlorinated biphenyls (PCBs) are a group of compounds, which have effects on the immune and nervous system. We have investigated the effects of seven diortho-substituted biphenyls with different substituents on activation of respiratory burst and calcium elevation in human granulocytes, and inhibition of the uptake of dopamine into synaptic vesicles and synaptosomes isolated from rat brain. We have attempted to find the chemical and physical properties, which can contribute to the variation in biological effects. These properties include the absolute hardness, the molecular size, the hydrophobicity of the molecules, the retention time on a DB5-MS GC-column and the electronegativity of the substituents. In general the dichloro- and dibromobiphenyls were the most potent in all biological tests. The difluorosubstituted was less potent than the other two halide-biphenyls presumably because of the smaller size of the substituent. Dimethylbiphenyl was active in all tests. Dihydroxy- and dimethanolbiphenyl were inactive in all tests, whereas dinitrobiphenyl was only active as a vesicular dopamine uptake inhibitor. Important physico-chemical parameters correlated to the effects were absolute hardness, molecular size and lipophilicity. Among the tested diortho-substituted biphenyls the most active were the chlorinated, brominated, and methylated. This indicates the significance of the molecular size in combination with the hydrophobicity for the studied toxic effects.
authors.affiliation: Norwegian Institute for Air Research, P.O. Box 100, 2027 Kjeller, Norway; Norwegian Defence Research Establishment, Division for Protection and Materiel, P.O. Box 25, N-2027 Kjeller, Norway.
authors.forename: Espen
authors.initials: E
authors.lastname: Mariussen
authors.forename: Patrik L
authors.initials: PL
authors.lastname: Andersson
authors.forename: Hege
authors.initials: H
authors.lastname: Olstørn
authors.forename: Oyvind A
authors.initials: OA
authors.lastname: Voie
authors.forename: Frode
authors.initials: F
authors.lastname: Fonnum