JBPC  Vol.2 No.3 , August 2011
The role of extracellular calcium in the effect of a snake venom Lys49-phospholipase A2 on water transport across epithelial membranes
ABSTRACT
ACLMT is a Lys49-phospholipase A2 myotoxin isolated from the venom of the Agkistrodon contortrix laticinctus snake. This study investigated the mechanisms involved in effect of ACLMT on membrane water permeability by examining the role of extracellular calcium and strontium in this effect. Water flow across the membrane was gravimetrically measured in bladder sac preparations. The decrease in extracellular calcium promoted a higher response of epithelium to ACLMT, suggesting that the extracellular calcium protects the membrane from the action of the toxin. No alteration in the effect of the toxin on water transport was observed when calcium was replaced by strontium, indicating that this effect is independent of its enzymatic activity. These findings may bring an important contribution towards the comprehension of the mechanisms involved in the effect of Lys49-phospholipase A2 myotoxins on water permeability of epithelial membranes, with implications for the understanding of renal toxicity.

Cite this paper
nullLeite, R. , Franco, W. and Selistre-de-Araujo, H. (2011) The role of extracellular calcium in the effect of a snake venom Lys49-phospholipase A2 on water transport across epithelial membranes. Journal of Biophysical Chemistry, 2, 222-225. doi: 10.4236/jbpc.2011.23027.
References
[1]   Lomonte, B., Angulo, Y. and Calderón, L. (2002) An overview of lysine-49 phospholipase A2 myotoxins from crotalid snake venoms and their structural determinants of myotoxic action. Toxicon, 42, 885-901. doi:10.1016/j.toxicon.2003.11.008

[2]   Boer-Lima, P.A., Gontijo, J.A.R. and Cruz-Hofling, M.A. (1999) Histologic and functional renal alterations caused by Bothrops moojeni snake venom in rats. The American Journal of Tropical Medicine and Hygiene, 61, 698-706.

[3]   Barbosa, P.S.F., Martins, A.M.C., Alves, R.S., Amora, D.N., Martins, R.D., Toyama, M.H., Havt, A., Nascimento, N.R.F., Rocha, V.L.C., Menezes, D.B., Fonteles, M.C. and Monteiro, H.S.A. (2006) The role of indomethacin and tezosentan on renal effects induced by Bothrops moojeni Lys49 myotoxin I. Toxicon, 47, 831- 837. doi:10.1016/j.toxicon.2006.01.012

[4]   Montecucco, C., Gutiérrez, J.M. and Lomonte, B. (2008) Cellular pathology induced by snake venom phospholipase A2 myotoxins and neurotoxins: Common aspects of their mechanisms of action. Cellular and Molecular Life Sciences, 65, 2897-2912. doi:10.1007/s00018-008-8113-3

[5]   Cintra-Francischinelli, M., Pizzo, P., Rodrigues-Simioni, L., Ponce-Soto, L.A., Rossetto, O., Lomonte, B., Gutiérrez, J.M., Pozzan, T. and Montecucco, C. (2009) Calcium imaging of muscle cells treated with snake myotoxins reveals toxin synergism and presence of acceptors. Cellular and Molecular Life Sciences, 66, 1718-1728. doi:10.1007/s00018-009-9053-2

[6]   Cintra-Francischinelli, M., Pizzo, P., Angulo, Y., Gutiérrez, J. M., Montecucco, C. and Lomonte, B. (2010) The C-terminal region of a Lys49 myotoxin mediates Ca+2 influx in C2C12 myotubes. Toxicon, 55, 590-596. doi:10.1016/j.toxicon.2009.10.013

[7]   Johnson, E.K. and Ownby, C.L. (1993) Isolation of a myotoxin from the venom of Agkistrodon contortrix laticinctus (broad-banded copperhead) and pathogenesis of myonecrosis induced by it in mice. Toxicon, 31, 243-255. doi:10.1016/0041-0101(93)90143-7

[8]   Leite, R.S., Franco, W., Ownby, C.L. and Selistre-de- Araujo, H.S. (2004) Effects of ACL myotoxin, a Lys49 phospholipase A2 from Agkistrodon contortrix laticinctus snake venom, on water transport in the isolated toad urinary bladder. Toxicon, 43, 77-83. doi:10.1016/j.toxicon.2003.10.024

[9]   Hardy, M.A. and Dibona, D.R. (1982) Extracellular Ca+2 and the effect of antidiuretic hormone on the water permeability of the toad urinary bladder: An example of flow induced alteration of flow. Journal of Membrane Biology, 67, 27-44. doi:10.1007/BF01868645

[10]   Fletcher, J. E. and Jiang, M. S. (1998) Lys49 phospholipase A2 myotoxins lyse cell cultures by two distinct mechanisms. Toxicon, 36, 1549-1555. doi:10.1016/S0041-0101(98)00147-0

[11]   Villalobos, J.C., Mora, R., Lomonte, B., Gutiérrez, J.M. and Angulo, Y. (2007) Cytotoxicity induced in myotubes by a Lys49 phospholipase A2 homologue from the venom of the snake Bothrops asper: Evidence of rapid plasma membrane damage and a dual role for extracellular calcium. Toxicology in Vitro, 21, 1382-1389. doi:10.1016/j.tiv.2007.04.010

[12]   Heluany, N.F., Homsi-Brandeburgo, M.L., Giglio, J.R., Prado-Fransceschi, J. and Rodrigues-Simioni, L. (1992) Effects induced by bothropstoxin, a component from Bothrops jararacussu snake venom, on mouse and chick muscle preparations. Toxicon, 30, 1203-1207. doi:10.1016/0041-0101(92)90436-9

[13]   Bashford, C.L., Alder, G.M., Graham, J.M., Menestrina, G. and Pasternak, C. (1988) Ion modulation of membrane permeability: Effect of cations on intact cells and on cells and phospholipid bilayers treated with pore-forming agents. Journal Membrane Biological, 103, 79-94. doi:10.1007/BF01871934

[14]   Rodrigues-Simioni, L., Prado-Franceschi, J., Cintra, A.C.O., Giglio, J.R., Jiang, M.S. and Fletcher, J.E. (1995) No role for enzymatic activity or dantrolene-sensitive Ca+2 stores in the muscular effects of bothropstoxin, a Lys49 phopholipase A2 myotoxin. Toxicon, 33, 1479-1489. doi:10.1016/0041-0101(95)00089-5

[15]   Barbosa, P.S.F., Martins, A.M.C., Havt, A., Toyama, D.O., Evangelista, J.S.A.M., Ferreira, D.P.P., Joazeiro, P.P., Beriam, L.O.S., Toyama, M.H., Fonteles, M.C. and Monteiro, H.S.A. (2005) Renal and antibacterial effects induced by myotoxin I and II isolated from Bothrops jararacussu venom. Toxicon, 46, 376-386. doi:10.1016/j.toxicon.2005.04.024

[16]   Hays, R. and Leaf, A. (1962) Studies on the movement of water through the isolated toad bladder and its modification by vasopressin. Journal of the American Society of Nephrology, 45, 905-919.

[17]   Leaf, A. (1982) From toad bladder to kidney. American Journal of Physiology, 242, 103-111.

 
 
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