TY - JOUR
T1 - Comparative cytotoxicity of monocrotaline and its metabolites in cultured pulmonary artery endothelial cells
AU - Taylor, D. W.
AU - Wilson, Dennis W
AU - Lamé, M. W.
AU - Dunston, S. D.
AU - Jones, A. D.
AU - Segall, H. J.
PY - 1997/3
Y1 - 1997/3
N2 - Metabolites of the pyrrolizidine alkaloid monocrotaline cause progressive development of pulmonary hypertension in rats. The putative reactive intermediate monocrotaline pyrrole (MCTP) has been shown to cause cytotoxicity, hypertrophy, decreased proliferation, and altered synthetic capability in cultured pulmonary endothelial cells. We compared effects of monocrotaline (MCT) at 60 μg/ml (0.185 mM) with previously identified metabolites, MCTP 10 μg/ml (0.031 mM) and glutathione-conjugated dihydropyrrolizine (GSH-DHP) 60 μg/ml (0.135 mM), in cultured bovine pulmonary artery endothelial cells (BPAECs). To determine whether endothelial metabolism might contribute to the mechanism of this toxicity, we used markers of cytotoxicity (LDH release), synthetic activity (PGI2 synthesis), hypertrophy (planimetry), cell density (cell count/area), and Evans blue albumin (EBA) transudation as a marker for loss of fluid barrier integrity. We found changes in all endothelial markers with MCTP only. MCTP caused increased LDH release by 48 hr, augmented PGI2 synthesis by 96 hr, and resulted in hypertrophy and decreased cell density by 48 hr that persisted at least 21 days. There was increased EBA transudation at 24 hr posttreatment. We concluded that, based on markers of endothelial damage, BPAECs showed no apparent ability to metabolize MCT to a reactive intermediate nor to further metabolize GSH-DHP to a toxic species. We also concluded that MCTP can cause a direct effect on fluid barrier integrity of endothelial cell monolayers in the absence of inflammation.
AB - Metabolites of the pyrrolizidine alkaloid monocrotaline cause progressive development of pulmonary hypertension in rats. The putative reactive intermediate monocrotaline pyrrole (MCTP) has been shown to cause cytotoxicity, hypertrophy, decreased proliferation, and altered synthetic capability in cultured pulmonary endothelial cells. We compared effects of monocrotaline (MCT) at 60 μg/ml (0.185 mM) with previously identified metabolites, MCTP 10 μg/ml (0.031 mM) and glutathione-conjugated dihydropyrrolizine (GSH-DHP) 60 μg/ml (0.135 mM), in cultured bovine pulmonary artery endothelial cells (BPAECs). To determine whether endothelial metabolism might contribute to the mechanism of this toxicity, we used markers of cytotoxicity (LDH release), synthetic activity (PGI2 synthesis), hypertrophy (planimetry), cell density (cell count/area), and Evans blue albumin (EBA) transudation as a marker for loss of fluid barrier integrity. We found changes in all endothelial markers with MCTP only. MCTP caused increased LDH release by 48 hr, augmented PGI2 synthesis by 96 hr, and resulted in hypertrophy and decreased cell density by 48 hr that persisted at least 21 days. There was increased EBA transudation at 24 hr posttreatment. We concluded that, based on markers of endothelial damage, BPAECs showed no apparent ability to metabolize MCT to a reactive intermediate nor to further metabolize GSH-DHP to a toxic species. We also concluded that MCTP can cause a direct effect on fluid barrier integrity of endothelial cell monolayers in the absence of inflammation.
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U2 - 10.1006/taap.1996.8083
DO - 10.1006/taap.1996.8083
M3 - Article
C2 - 9073608
AN - SCOPUS:0031106034
VL - 143
SP - 196
EP - 204
JO - Toxicology and Applied Pharmacology
JF - Toxicology and Applied Pharmacology
SN - 0041-008X
IS - 1
ER -