Cardiac dysrhythmia produced by Mesobuthus tamulus venom involves NO-dependent G-Cyclase signaling pathway

  • Sadhana Kanoo
  • Maloy B. Mandal
  • Anitha B. Alex
  • Shripad B. DeshpandeEmail author
Original Article


Role of G-protein coupled pathways in modulating the cardiotoxic effects produced by Indian red scorpion (Mesobuthus tamulus) venom were examined. The isometric contractions of spontaneously beating or paced (3.5 Hz) rat right atrial preparations in vitro were recorded. The cumulative concentration (0.01–3.0 μg/ml)-response of venom on spontaneously beating atria exhibited a marked decrease in rate (by 55%) and an increase in force (by 92%) only at a higher concentration (3.0 μg/ml). The venom-induced decrease in rate and increase in force were sensitive to atropine, N-ω-nitro-l-arginine methylester (NO synthase inhibitor) and methylene blue (guanylyl cyclase inhibitor). Further, nifedipine, a Ca2+ channel antagonist, blocked the force changes but not the rate changes induced by venom. In the paced atrium, on the other hand, a concentration-dependent decrease in force was observed, and at 3 μg/ml, the decrease was 50%. Pretreatment with nifedipine, but not with methylene blue, significantly attenuated the venom-induced force changes in paced atrium. The observations of this study demonstrate that the venom-induced atrial dysrhythmia is mediated through the muscarinic receptor-dependent NO-G-cyclase cell-signaling pathways.


c-GMP Guanylyl cyclase Indian red scorpion venom l-NAME Methylene blue Nifedipine 



SK wishes to thank University Grants Commission, New Delhi for the financial assistance.


  1. Abi-Gerges N, Hove-Madsen L, Fischmeister R, Me’ry PF (1997) A comparative study of the effects of three guanylyl cyclase inhibitors on the L-type Ca2+ and muscarinic K+ currents in frog cardiac myocytes. Br J Pharmacol 121:1369–1377PubMedCrossRefGoogle Scholar
  2. Alex AB, Deshpande SB (1999) Indian red scorpion venom modulates spontaneous activity of rat right atria through the involvement of cholinergic and adrenergic systems. Indian J Exp Biol 37:455–460PubMedGoogle Scholar
  3. Alex AB, Kanoo S, Deshpande SB (2006) Estrogen modulates in vitro atrial bradycardia induced by Indian red scorpion venom via G-protein coupled mechanisms. Eur J Pharmacol 546:102–108PubMedCrossRefGoogle Scholar
  4. Cannon SD, Wilson SP, Walsh KB (1994) A G protein-activated K+ current in bovine adrenal chromaffin cells: possible regulatory role in exocytosis. Mol Pharmacol 45:109–116PubMedGoogle Scholar
  5. Chen H, Heinemann SH (2001) Interaction of scorpion alpha-toxin with cardiac sodium channels: binding properties and enhancement of slow inactivation. J Gen Physiol 117:505–518PubMedCrossRefGoogle Scholar
  6. De Marco T, Dae M, Yuen-Green MS, Kumar S, Sudhir K, Keith F, Amidon TM, Rifkin C, Klinski C, Lau D, Botvinick H, Chatterjee K (1995) Iodine-123 metaiodobenzylguanidine scintigraphic assessment of the transplanted human heart: evidence for late reinnervation. J Am Coll Cardiol 25:927–931PubMedCrossRefGoogle Scholar
  7. Deshpande SB, Alex AB, Jagannadham MV, Rao GRK, Tiwari AK (2005) Identification of a novel pulmonary oedema producing toxin from the Indian red scorpion (Mesobuthus tamulus) venom. Toxicon 45:735–743PubMedCrossRefGoogle Scholar
  8. Dhawan RD, Joseph S, Sethi A, Lala AK (2002) Purification and characterization of a short insect toxin from the venom of the scorpion Buthus tamulus. FEBS Lett 528:261–266PubMedCrossRefGoogle Scholar
  9. Feron O, Dessy C, Douglas J, Douglas JO, Margaret AA, Ralph AK (1998) Modulation of the endothelial nitric-oxide synthase-caveolin interaction in cardiac myocytes. J Biol Chem 273:30249–30254PubMedCrossRefGoogle Scholar
  10. Fischmeister R, Me’ry PF (1996) Regulation of cardiac calcium current by cGMP/NO route. In: Morad M, Ebashi S, Trautwein W, Kurachi Y (eds) Molecular physiology and pharmacology of cardiac ion channels and transporters. Kluwer, Dordrecht, pp 93–105Google Scholar
  11. Fischmeister R, Castro L, Abi-Gerges A, Rochais F, Vandecasteele G (2005) Species and tissue-dependent effects of NO and cyclic GMP on cardiac ion channels. Comp Biochem Physiol A Mol Integr Physiol 142:136–143PubMedCrossRefGoogle Scholar
  12. Friebe A, Koesling D (2003) Regulation of nitric oxide-sensitive guanylyl cyclase. Circ Res 93:96–105PubMedCrossRefGoogle Scholar
  13. Galvez A, Gimenez-Gallego G, Reuben JP, Roy-contancin L, Feigenbaum P, Kaczorowski GJ, Garcia ML (1990) Purification and characterization of a unique, potent, peptidyl probe for the high conductance calcium-activated potassium channel from venom of the scorpion Buthus tamulus. J Biol Chem 265:11083–11090PubMedGoogle Scholar
  14. Han X, Shimoni Y, Giles WR (1995) A cellular mechanism for Nitric oxide-mediated cholinergic control of mammalian heart rate. J Gen Physiol 106:45–65PubMedCrossRefGoogle Scholar
  15. Herring N, Paterson DJ (2001) Nitric oxide-cGMP pathway facilitates acetylcholine release and bradycardia during vagal nerve stimulation in the guinea-pig in vitro. J Physiol 535:507–518PubMedCrossRefGoogle Scholar
  16. Herring N, Danson EJE, Paterson DJ (2002) Cholinergic control of heart rate by nitric oxide is site specific. News Physiol Sci 17:202–206PubMedGoogle Scholar
  17. Heydrick SJ, Reed KL, Cohen PA, Aarons CB, Gower GC, Becker JM, Stucchi AF (2007) Intraperitoneal administration of methylene blue attenuates oxidative stress, increase peritoneal fibrinolysis, and inhibits intraabdominal adhesion formation. J Surg Res 143:311–319PubMedCrossRefGoogle Scholar
  18. Kass DA, Takimoto E, Nagayama T, Champion HC (2007) Phosphodiesterase regulation of nitric oxide signaling. Cardiovas Res 75:303–314CrossRefGoogle Scholar
  19. Lindemann JP, Watanabe AM (1991) Mechanism of adrenergic and cholinergic regulation of myocardial contractility. In: Sperelakis N (ed) Physiology and pathophysiology of heart, 2nd edn. Kluwer Acad Publisher, Boston, pp 423–452Google Scholar
  20. Mukumov MR, Isaeva SA, Belaya ML, Pratusevich VR (1992) Force-frequency relations in hypertrophic heart muscle: a mathematical model for excitation contraction coupling. Gen Physiol Biophys 11:523–533PubMedGoogle Scholar
  21. Murad F (1999) Discovery of some of the biological effects of nitric oxide and its role in cell signaling. Biosci Rep 19:133–154PubMedCrossRefGoogle Scholar
  22. Murthy KR, Vakil AE (1988) Elevation of plasma angiotensin levels in dogs by Indian red scorpion (Buthus tamulus) venom & its reversal by administration of insulin + tolazoline. Ind J Med Res 88:376–379Google Scholar
  23. Murthy KRK, Yeolekar ME (1986) Electrocardiographic changes in experimental myocarditis induced by scorpion (Buthus tamulus) venom. Indian Heart J 38:206–210Google Scholar
  24. Natu VS, Murthy KRK, Deodhar KP (2006) Efficacy of species specific anti-scorpion venom serum (AscVS) against severe, serious scorpion stings (Mesobuthus tamulus concanensis Pocock)—an experience from rural hospital in Western Maharashtra. J Assoc Physicians India 34:283–287Google Scholar
  25. Pandey R, Deshpande SB (2004) Protective effect of aprotinin on respiratory and cardiac abnormalities induced by Mesobuthus tamulus venom in adult rats. Toxicon 44:201–205PubMedCrossRefGoogle Scholar
  26. Pandey R, Deshpande SB (2007) Aprotinin reverses ECG abnormalities induced by Mesobuthus tumulus venom in adult rats. Ind J Exp Biol 45:949–953Google Scholar
  27. Pedarzani P, D’hoedt D, Doorty KB, Wadsworth JD, Joseph JS, Jayasheelan K, Kini RM, Gadre SV, Sapatnekar SM, Stocker M, Strong PN (2002) Tamapin, a venom peptide from the Indian red scorpion (Mesobuthus tamulus) that targets small conductance Ca2+-activated K+ channels and after hyperpolarisation currents in central neurons. J Biol Chem 277:46101–46109PubMedCrossRefGoogle Scholar
  28. Pfaffinger PJ, Martin JM, Hunter DD, Nathanson NM, Hille B (1985) GTB-binding proteins couple cardiac muscarinic receptors to a K channel. Nature 317:536–538PubMedCrossRefGoogle Scholar
  29. Rastaldo R, Pagliaro P, Cappello S, Penna C, Mancardi D, Westerhof N, Losano G (2007) Nitric oxide and cardiac function. Life Sci 81:779–793PubMedCrossRefGoogle Scholar
  30. Rowan EG, Vatanpour H, Furman BL, Harvey AL, Taniva MOM, Gopalkrishnakone P (1992) The effects of Indian red scorpion Buthus tamulus venom in vivo and in vitro. Toxicon 30:1157–1164PubMedCrossRefGoogle Scholar
  31. Seya K, Furukawa K, Yoshida K, Narita R, Motomura S (2005) Nifedipine enhances cGMP production through the activation of soluble guanylyl cyclase in rat ventricular papillary muscle. J Pharm Pharmacol 57:511–514PubMedCrossRefGoogle Scholar
  32. Strong PN, Clark GS, Armugam A, De-Allie FA, Joseph JS, Yemul V, Deshpande JM, Kamat R, Gadre SV, Gopalakrishnaakone P, Kini RM, Owen DG, Jayaseelan K (2001) Tamulus toxin: a novel potassium channel blocker from the venom of the Indian red scorpion Mesobuthus tamulus. Arch Biochem Biophys 385:138–144PubMedCrossRefGoogle Scholar
  33. Sun HY, Zhu HF, Ji YH (2003) BmK I, an alpha-like scorpion neurotoxin, specially modulates isolated rat cardiac mechanical and electrical activity. Acta Physiol Sin 55:530–534Google Scholar
  34. Teixeira CE, Bento AC, Lopes-Martins RAB, Teixeira SA, Eickestedt V, Muscara MN, Arantes EC, Giglio JR, Antunes E, Nucci G (1998) Effect of Tityus serrulatus scorpion venom on the rabbit isolated corpus cavernosum and the involvement of NANC nitrergic nerve fibres. Br J Pharmacol 123:435–442PubMedCrossRefGoogle Scholar
  35. Wang H, Guo Z-D, Li Z, Liu H-R (2002) Effects of various muscarinic ligands on M2AChR. \({\text{G}}_{{\text{i}}1\alpha } \) fusion protein expressed in Sf9 insect cells. Acta Pharmacol Sin 23:230–236PubMedGoogle Scholar
  36. Wudayagiri R, Inceoglu B, Herrmann R, Derbel M, Choudary PV, Hammock BD (2001) Isolation and characterization of a novel lepidopteran-selective toxin from the venom of South Indian red scorpion, Mesobuthus tamulus. BMC Biochem 2:16–28PubMedCrossRefGoogle Scholar
  37. Yatani A, Codina J, Brown AM, Birnbaumer L (1987) Direct activation of mammalian atrial muscarinic potassium channels by GTP regulatory protein Gk. Science 235:207–211PubMedCrossRefGoogle Scholar
  38. Yatani A, Okabe K, Codina J, Birnbaumer L, Brown AM (1990) Heart rate regulation by G proteins acting on the cardiac pacemaker channel. Science 249:1163–1166PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • Sadhana Kanoo
    • 1
  • Maloy B. Mandal
    • 1
  • Anitha B. Alex
    • 1
  • Shripad B. Deshpande
    • 1
    Email author
  1. 1.Department of Physiology, Institute of Medical SciencesBanaras Hindu UniversityVaranasiIndia

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