Abstract
The effects of the herbicides paraquat, dinoseb and 2,4-D on intracellular Ca2+ levels and on vasopressin-induced Ca2+ mobilization were investigated in intact isolated hepatocytes. Incubation of rat hepatocytes with paraquat (5 mM for 60 min) and dinoseb (10 μM) resulted in a time-dependent loss of viability by approximately 25%. Viability of cells treated with 2,4-D decreased significantly, dropping to about 20% at 10 mM and 60 min incubation. Exposure of hepatocytes to paraquat (1–10 mM) for 60 min had no effect on the basal level of [Ca2+] i . Additionally, exposure to paraquat had no effect on the magnitude and on the duration of the [Ca2+] i response to vasopressin. In the presence of 2,4-D (1–10 mM), basal [Ca2+] i increases as a function of herbicide concentration. The magnitude of the Δ[Ca2+] i response decreases from 256± 8nM in control to 220 ± 5nM, at 10mM 2,4-D. Exposure of hepatocytes to dinoseb (1–10 μM) had no effect on the basal level of [Ca2+] i . However, a strong concentration-dependent decrease in the magnitude of Δ[Ca2+] i in response to vasopressin was noticed at 60 min incubation. Dinoseb markedly inhibited the stimulation of the production of inositol phosphates by vasopressin stimulus. The present study demonstrates that paraquat, 2,4-D and dinoseb cause cell death in hepatocytes by mechanisms not related to an early increase in [Ca2+] i . Additionally, it has been shown for the first time that dinoseb disturbs the transduction mechanism promoted by vasopressin by inhibiting the formation of IP3.
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Abbreviations
- Paraquat :
-
1,1′-dimethyl-4,4′-bipyridylium dichloride, dinoseb 2-sec-butyl-4,6-dinitrophenol, 2,4-D 2,4-dichlorophenoxyacetic acid
- [Ca2+] i :
-
free intracellular calcium concentration
- IP1 :
-
inositol 4-monophosphate
- IP2 :
-
inositol 1,4-bisphosphate
- IP3 :
-
inositol 1,4,5-trisphosphate
- IP4 :
-
inositol 1,3,4,5-tetrakisphosphate
References
Bellomo G, Orrenius S (1985) Altered thiol and calcium homeostasis in oxidative hepatocellular injury. Hepatology 5: 876–882
Bellomo G, Thor H, Orrenius S (1987) Alterations in inositol phosphate production during oxidative stress in isolated hepatocytes. J Biol Chem 262: 1530–1534
Berridge MJ, Irvine RF (1989) Inositol phosphates and cells signalling. Nature 341: 197–205
Berridge MJ, Dawson RMC, Downes CP, Heslop JP, Irvine, RF (1983) Changes in the levels of inositol phosphates after agonist-dependent hydrolysis of membrane phosphoinostitides. Biochem J 212: 473–482
Bygrave FL, Benedetti A (1993) Calcium: its modulation in liver by cross-talk between the actions of glucagon and calcium-mobilizing agonists. Biochem J 296: 1–14
Carafoli E (1987) Intracellular calcium homeostasis. Ann Rev Biochem 56: 395–433
Carpenter-Deyo L, Reed DJ (1991) Involvement of calcium and iron in Quin-2 toxicity to isolated hepatocytes. J Pharmacol Exp Ther 258: 747–752
Casini AF, Maellaro E, Pompella A, Ferrali M, Comporti M (1987) Lipid peroxidation, protein thiols and calcium homeostasis in bromobenzene-induced liver damage. Biochem Pharmacol 36: 3689–3695
Charest R, Prpic V, Exton JH, Blackmore PF (1985) Stimulation of inositol trisphosphate formation in hepatocytes by vasopressin, adrenaline and angiotensin II and its relationship to changes in cytosolic free Ca2+. Biochem J 227: 79–90
Glennon MC, Bird GJ, Kwan C-Y, Putney Jr JW (1992) Actions of vasopressin and the Ca2+-ATPase inhibitor, thapsigargin, on Ca2+ signaling in hepatocytes. J Biol Chem 267: 8230–8233
Grewal KK, Racz WJ (1993) Intracellular calcium disruption as a secondary event in acetaminophen-induced hepatotoxicity. Can J Physiol Pharmacol 71: 26–33
Grynkiewicz G, Poenie M, Tsien RY (1985) A new generation of Ca2+ indicators with greatly improved fluorescence properties. J Biol Chem 260: 3440–3450
Guillemette G, Balla T, Baukal AJ, Catt KJ (1988) Characterization of inositol 1,4,5-trisphosphate receptors and Ca2+ mobilization in an hepatic plasma membrane fraction. J Biol Chem 264: 15192–15198
Hardwick SJ, Wilson JW, Fawthrop DJ, Boobis AR, Davies DS (1992) Paraeetamil toxicity in hamster isolated hepatocytes: the increase in cytosolic calcium accompanies, rather than precedes, loss of viability. Arch Toxicol 66: 408–412
Iaizzo PA, Seewald MJ, Powis G, Van Dyke RA (1993) The effects of sevoflurane on intracellular Ca2+ regulation in rat hepatocytes. Toxicol Lett 66: 81–88
Joseph SK, Thomas AP, Williams RJ, Irvine RF, Williamson JR (1984) myo-Inositol 1, 4, 5-trisphosphate. A second messenger for the hormonal mobilization of intracellular Ca2+ in liver. J Biol Chem 259: 3077–3081
Kass GEN, Duddy SK, Moore GA, Orrenius S (1989) 2,5-Di-(tert-butyl)-1,4-benzohydroquinone rapidly elevates cytosolic Ca2+ concentration by mobilizing the inositol 1,4,5-trisphosphatesensitive Ca2+ pool. J Biol Chem 264: 15192–15198
Kawanishi T, Blank LM, Harootunian AT, Smith MT, Tsien RY (1989) Ca2+ oscillations induced by hormonal stimulation of individual Fura-2-loaded hepatocytes. J Biol Chem 264: 12859–12866
Kraus-Friedmann N (1990) Calcium sequestation in the liver. Cell Calcium 11: 625–640
Lemasters JJ, DiGuiseppi J, Niemien A-L Herman B (1987) Blebbing, free Ca2+ and mitochondrial membrane potential preceding cell death in hepatocytes. Nature 325: 78–81
Mayeux PR, Shah SV (1993) Intracellular calcium mediates the cytotoxicity of lipid A in LLC-PK1 cells. J Pharmacol Exp Ther 266: 47–51
Moldéus P, Hogberg J, Orrenius S (1978) Isolation and use of liver cells. In: Fleischer S, Packer L (eds) Methods in Enzymology, vol 52, Academic Press, New York, pp 60–71
Orrenius S, McConkey DJ, Bellomo G, Nicotera P (1989) Role of Ca2+ in toxic cell killing. Trends Pharmacol Sci 10: 281–285
Palmeira CM, Moreno AJ, Madeira VMC (1994) Metabolic alterations promoted by the herbicides paracquat, dinoseb and 2,4-D. Arch Toxicol 68: 24–31
Starke PE, Hoek JB, Farber JL (1986) Calcium-dependent and calcium independent mechanisms of irreversible cell injury in cultured hepatocytes. J Biol Chem 261: 3006–3012
Stevens JT, Sumner DD (1991) Herbicides. In: Handbook of pesticide toxicology, vol 3, pp 1317–1391, Academic Press, New York
Thomas AP, Alexander J, Williamson JR (1984) Relationship between inositol polyphosphate production and the increase of cytosolic free Ca2+ induced by vasopressin in isolated hepatocytes. J Biol Chem 259: 5574–5584
Tsunoda Y (1993) Receptor-operated Ca2+ signaling and crosstalk in stimulus secretion coupling. Biochim Biophys Acta 1154: 105–156
Ware GW (1978) Chemicals used in the control of plants. In: The pesticide book, W. H. Freeman, San Francisco, pp 75–94
Zoteweij JP, Van de Water B, de Bont HJGM, Mulder GJ, Nagelkerke JF (1993) Calcium-induced cytotoxicity in hepatocytes after exposure to extracellular ATP is dependent on inorganic phosphate. Effects on mitochondrial calcium. J Biol Chem 268: 3384–3388
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Palmeira, C.M., Moreno, A.J. & Madeira, V.M.C. Effects of paraquat, dinoseb and 2,4-D on intracellular calcium and on vasopressin-induced calcium mobilization in isolated hepatocytes. Arch Toxicol 69, 460–466 (1995). https://doi.org/10.1007/s002040050199
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DOI: https://doi.org/10.1007/s002040050199