Differential effects of triphenylphosphite and diisopropyl phosphorofluoridate on catecholamine secretion from bovine adrenomedullary chromaffin cells.
J Toxicol Environ Health 1993 Feb; 38(2):103-114
The neurotoxic effects of triphenyl-phosphite (115866) (TPP) were studied. Chromaffin cells were isolated from bovine adrenal medullae and exposed to TPP or diisopropyl-phosphorofluoridate (55914) (DFP) for 24 hours with or without preincubation with nicotine, veratridine or potassium. A time and dose dependent decrease in the release of catecholamines by the chromaffin cells was seen following incubation with TPP. An inhibition of nicotine, veratridine, and potassium ion induced secretion was seen as well with exposure to TPP. Nicotine induced secretion was not affected by incubation with DFP or paraoxon (311455); however, these compounds significantly increased secretion in the presence of potassium. Nicotine or potassium stimulated calcium uptake by the cells was inhibited by TPP and unaffected by DFP. Under basal conditions, however, TPP stimulated calcium uptake and DFP inhibited calcium uptake after 5 minutes of incubation. Both TPP and DFP inhibited the activity of the enzyme neurotoxic-esterase. The authors conclude that the mechanism of TPP induced toxicity may involve changes in cell secretory processes.
NIOSH-Publication; NIOSH-Grant; Neurotoxic-effects; Cellular-function; Neurotransmitters; In-vitro-study; Organo-phosphorus-compounds; Biochemical-analysis; Mammalian-cells
Pharmacology Duke University Department of Pharmacology Durham, N C 27710
115-86-6; 55-91-4; 311-45-5
Journal of Toxicology and Environmental Health
Duke University, Durham, North Carolina