Biological Trace Element Research

, Volume 187, Issue 2, pp 418–424 | Cite as

Calcium Channels, Rho-Kinase, Protein Kinase-C, and Phospholipase-C Pathways Mediate Mercury Chloride-Induced Myometrial Contractions in Rats

  • Swati Koli
  • Atul Prakash
  • Soumen Choudhury
  • Rajesh Mandil
  • Satish K. GargEmail author


Adverse effects of mercury on female reproduction are reported; however, its effect on myogenic activity of uterus and mechanism thereof is obscure. Present study was undertaken to unravel the mechanistic pathways of mercuric chloride (HgCl2)-induced myometrial contraction in rats. Isometric tension in myometrial strips of rats following in vitro exposure to HgCl2 was recorded using data acquisition system-based physiograph. HgCl2 produced concentration-dependent (10 nM–100 μM) uterotonic effect which was significantly (p < 0.05) reduced in Ca2+-free solution and inhibited in the presence of nifedipine (1 μM), a L-type Ca2+ channel blocker, thus suggesting the importance of extracellular Ca2+ and its entry through L-type calcium channels in HgCl2-induced myometrial contractions in rats. Cumulative concentration-response curve of HgCl2 was significantly (p < 0.05) shifted towards right in the presence of Y-27632 (10 μM), a Rho-kinase inhibitor, suggesting the involvement of Ca2+-sensitization pathway in mediating HgCl2-induced myometrial contraction. HgCl2-induced myometrial contraction was also significantly (p < 0.05) inhibited in the presence of methoctramine or para-fluoro-hexahydro-siladifenidol, a selective M2 and M3 receptor antagonists, respectively, which evidently suggest that mercury also interacts with M2 and M3 muscarinic receptors to produce myometrial contractions. U-73122 and GF-109203X, the respective inhibitors of PLC and PKC-dependent pathways, downstream to the receptor activation, also significantly (p < 0.05) attenuated the uterotonic effect of HgCl2 on rat uterus. Taken together, present study evidently reveals that HgCl2 interacts with muscarinic receptors and activates calcium signaling cascades involving calcium channels, Rho-kinase, protein kinase-C, and phospholipase-C pathways to exert uterotonic effect in rats.

Graphical Abstract

Graphical abstract depicting the mechanism of mercury-induced myometrial contraction in rats. M receptor: Muscarinic receptor; PIP2: phospho-inositol bisphosphate; PLC: phospholipase-C; DAG: diacyl glycerol; IP3: inositol triphosphate; IP3R: inositol triphosphate receptor; PKC; protein kinase-C; MLCP: myosin light chain phosphatise; MYPT: myosin phosphatase; SR: sarco-endoplasmic reticulum


Mercury Myometrium VDCC Calcium Muscarinic receptor PKC PLC Rho-kinase 



Research work presented in this manuscript was undertaken in the research project funded by Indian Council of Agricultural Research, New Delhi, India, under Niche Area of Excellence Programme (Grant No. 10 (10)/2012-EPD dated 23rd march 2012) to Department of Veterinary Pharmacology and Toxicology, DUVASU, Mathura, India. Financial assistance from ICAR is thankfully acknowledged.

Compliance with Ethical Standards

Conflict of Interest

The authors declare that they have no conflict of interest.


  1. 1.
    Abdalla FM, Marostica E, Picarelli ZP, Abreu LC, Avellar MC, Porto CS (2004) Effect of estrogen on muscarinic acetylcholine receptor expression in rat myometrium. Mol Cell Endocrinol 213(2):139–148CrossRefGoogle Scholar
  2. 2.
    Papka RE, Trauring HH, Schemann M, Collins J, Copelin T, Wilson K (1999) Cholinergic neurons of the pelvic autonomic ganglia and uterus of the female rat: distribution of axons and presence of muscarinic receptors. Cell Tissue Res 296(2):293–305CrossRefGoogle Scholar
  3. 3.
    Maggi M, Baldi E, Susini T (1994) Hormonal and local regulation of uterine activity during parturition. Part I. The oxytocin system. J Endocrinol Investig 17:739–756CrossRefGoogle Scholar
  4. 4.
    Maggi M, Baldi E, Susini T (1994) Hormonal and local regulation of uterine activity during parturition: part II—the prostaglandin and adrenergic systems. J Endocrinol Investig 17:757–770CrossRefGoogle Scholar
  5. 5.
    Taggart MJ (2001) Smooth muscle excitation-contraction coupling: a role for caveolae and caveolins? News Physiol Sci 16:61–65PubMedGoogle Scholar
  6. 6.
    Luckas JJ, Taggart MJ, Wray S (1999) Intracellular calcium stores and agonist-induced contractions in isolated human myometrium. Am J Obstet Gynecol 181:468–476CrossRefGoogle Scholar
  7. 7.
    Fu X, Liu YJ, Ciray N, Olovsson M, Ulmsten U, Gylfe E (2000) Oxytocin-induced oscillations of cytoplasmic Ca2+ in human myometrial cells. Acta Obstet Gynecol Scand 79:174–179CrossRefGoogle Scholar
  8. 8.
    Berridge MJ, Irvine RF (1989) Inositol phosphates and cell signalling. Nature 341(6239):197e205CrossRefGoogle Scholar
  9. 9.
    Kevin MR, Ernest MW, Miaozong W, Chris G, Eric RB (2014) Environmental mercury and its toxic effects. J Prev Med Public Health 47(2):74–83CrossRefGoogle Scholar
  10. 10.
    Ghosh AK, Sen S, Sharma A, Talukder G (1991) Effect of chlorophyllin on mercuric chloride-induced clasogenicity in mice. Food Chem Toxicol 29:777–779CrossRefGoogle Scholar
  11. 11.
    Solecki R, Hothorn L, Holzweissig M, Heinrich V (1991) Computerised analysis of pathological findings in longterm trials with phenylmercuric acetate in rats. In: Chambers PL, Chambers CM, Wiezorek WD, Golbs S (eds) Recent developments in toxicology: trends, methods and problems. Archives of Toxicology, Springer, Berlin, Heidelberg, pp 100–103CrossRefGoogle Scholar
  12. 12.
    NTP (1993) Toxicology and carcinogenesis studies of mercuric chloride (CAS no. 7487-94-7) in F344/N rats and B6C3F1 mice (gavage studies). National Toxicology Programme, US Department of Health and Human Service, National Institutes of Health, research Triangle Park, NC. NTP TR 408. NIH Publication No 91–3139Google Scholar
  13. 13.
    Fuyuta M, Fujimotto T, Kiyofuji E (1979) Teratogenic effects of a single oral administration of methylmercuric chloride in mice. Acta Anat (Basel) 104:356–362CrossRefGoogle Scholar
  14. 14.
    Elghany NA, Stopford W, Bunn WB, Fleming LE (1997) Occupational exposure to inorganic mercury vapor and reproductive outcomes. Occup Med 47(6):333–336CrossRefGoogle Scholar
  15. 15.
    Davis B, Price H, O’Connor R, Fernando R, Rowland A, Morgan D (2001) Mercury vapor and female reproductive toxicity. Toxicol Sci 59(2):291–296CrossRefGoogle Scholar
  16. 16.
    Baranshi B, Szmczyk I (1973) Effects of mercury vapour upon reproductive function of female white rats. Med Pr 24:248Google Scholar
  17. 17.
    Stadnicka A (1980) Localization of mercury in the rat ovary after oral administration of mercuric chloride. Acta Histochem 67(2):227–233CrossRefGoogle Scholar
  18. 18.
    Burbacher TM, Mohammed MK, Mottett NK (1988) Methylmercury effects on reproduction and offspring size at birth. Reprod Toxicol 1(4):267–278CrossRefGoogle Scholar
  19. 19.
    Nakade UP, Garg SK, Sharma A, Choudhury S, Yadav RS, Gupta K, Sood N (2015) Lead-induced adverse effects on the reproductive system of rats with particular reference to histopathological changes in uterus. Indian J Pharm 47(1):22–26CrossRefGoogle Scholar
  20. 20.
    Saroj VK, Nakade UP, Sharma A, Yadav RS, Hajare SW, Garg Satish K (2017) Functional involvement of L-type calcium channels and cyclic nucleotide-dependent pathways in cadmium-induced myometrial relaxation in rats. Hum Exp Toxicol 36(3):276–286CrossRefGoogle Scholar
  21. 21.
    Saroj VK, Nakade UP, Sharma A, Choudhury S, Hajare SW, Garg Satish K (2018) Dose-dependent differential effects of in vivo exposure of cadmium on myometrial activity in rats: involvement of VDCC and Ca2+-mimicking pathways. Biol Trace Elem Res 181(2):272–280CrossRefGoogle Scholar
  22. 22.
    Nakade UP, Sharma A, Choudhury S, Yadav RS, Garg Satish K (2017) Lead modulates calcium entry and beta-adrenoceptors signalling to produce myometrial relaxation in rats. Biol Trace Elem Res 176(1):176–180CrossRefGoogle Scholar
  23. 23.
    Candura SM, D'Agostino G, Castoldi AF, Messori E, Liuzzi M, Manzo L, Tonini M (1997) Effects of mercuric chloride and methyl mercury on cholinergic neuromuscular transmission in the guinea-pig ileum. Pharmacol Toxicol 80(5):218–224CrossRefGoogle Scholar
  24. 24.
    Moberg LE (1986) Effects of mercuric ions on isolated guinea-pig ileum. Acta Odontol Scand 44(4):207–213CrossRefGoogle Scholar
  25. 25.
    Hare MF, Rezazadeh SM, Cooper GP, Minnema DJ, Michaelson IA (1990) Effects of inorganic mercury on [3H] dopamine release and calcium homeostasis in rat striatal synaptosomes. Toxicol Appl Pharmacol 102(2):316–330CrossRefGoogle Scholar
  26. 26.
    Binah O, Meiri U, Rahamimoff H (1978) The effects of HgCl2 and mersalyl on mechanisms regulating intracellular calcium and transmitter release. Eur J Pharmacol 51(4):453–457CrossRefGoogle Scholar
  27. 27.
    Fukushi Y, Wakui M (1985) Inhibitory effect of methylmercuric chloride on the contraction mediated by muscarinic receptor of intestinal smooth muscle of the guinea-pig. Tohoku J Exp Med 147(1):33–41CrossRefGoogle Scholar
  28. 28.
    Anabuki J, Hori M, Hayakawa K, Akahane S, Ozaki H, Karaki H (2000) Muscarinic stimulation does not induce rhoA/ROCK-mediated Ca2+ sensitization of the contractile element in chicken gizzard smooth muscle. Pflugers Arch 441(2–3):189–199CrossRefGoogle Scholar
  29. 29.
    Aronstam RS, Elderfrawi ME (1979) Transition and heavy metal inhibition of ligand binding to muscarinic acetylcholine receptors from rat brain. Toxicol Appl Pharmacol 48(3):489–496CrossRefGoogle Scholar
  30. 30.
    Castoldi AF, Candura SM, Costa P, Manzo L, Costa LG (1996) Interaction of mercury compounds with muscarinic receptor subtypes in rat brain. Neurotoxicology 17(3–4):735–741PubMedGoogle Scholar
  31. 31.
    Varol FG, Hadjiconstantinou M, Zuspan FP, Neff NH (1989) Pharmacological characterization of the muscarinic receptors mediating phosphoinositide hydrolysis in rat myometrium. J Pharmacol Exp Ther 249(1):11–15PubMedGoogle Scholar
  32. 32.
    Pennefather JN, Gillman TA, Mitchelson F (1994) Muscarinic receptors in rat uterus. Eur J Pharmacol 262(3):297–300CrossRefGoogle Scholar
  33. 33.
    Limke TL, Bearss JJ, Atchison WD (2004) Acute exposure to methylmercury causes Ca2+ dysregulation and neuronal death in rat cerebellar granule cells through an M3 muscarinic receptor-linked pathway. Toxicol Sci 80:60–68CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  • Swati Koli
    • 1
  • Atul Prakash
    • 1
  • Soumen Choudhury
    • 1
  • Rajesh Mandil
    • 1
  • Satish K. Garg
    • 1
    Email author
  1. 1.Experimental Pharmacology Laboratory, Department of Veterinary Pharmacology and Toxicology, College of Veterinary Science and Animal HusbandryU.P. Pandit Deen Dayal Upadhyaya Pashu Chikitsa Vigyan Vishwavidyalaya Evam Go-Anusandhan Sansthan (DUVASU)MathuraIndia

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