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Hyponatraemia reversibly affects human myometrial contractility. An in vitro pilot study


Autoři: Vibeke Moen aff001;  Lars Brudin aff003;  Anette Ebberyd aff004;  Maria Sennström aff005;  Gunvor Ekman-Ordeberg aff005;  Mats Rundgren aff004;  Lars Irestedt aff002
Působiště autorů: Department of Anaesthesiology and Intensive Care, Region Kalmar County, Kalmar, Sweden aff001;  Department of Physiology and Pharmacology, Division of Anaesthesiology and Intensive Care, Karolinska Institutet, Stockholm, Sweden aff002;  Department of Medicine, and Health Sciences, Linköping University, Linköping, Sweden aff003;  Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden aff004;  Department of Women and Children´s Health, Division of Obstetrics and Gynecology, Karolinska Institutet, Stockholm, Sweden aff005
Vyšlo v časopise: PLoS ONE 15(1)
Kategorie: Research Article
doi: https://doi.org/10.1371/journal.pone.0220020

Souhrn

Background

In a previous study we found a significant correlation between dystocia and hyponatraemia that developed during labour. The present study examined a possible causal relationship. In vitro studies often use area under the curve (AUC) determined by frequency and force of contractions as a measure of myometrial contractility. However, a phase portrait plot of isometric contraction, obtained by plotting the first derivate of contraction against force of contraction, could indicate that bi-or multiphasic contractions might be less effective compared to the smooth contractions.

Material and methods

Myometrial biopsies were obtained from 17 women undergoing elective caesarean section at term. Each biopsy was divided into 8 strips and mounted isometrically in a force transducer. Seven biopsies were used in the first part of the study when half of the strips were immersed in the hyponatraemic study solution S containing Na+ 120 mmol/L and observed for 1 hour, followed by 1 hour in normonatraemic control solution C containing Na+ 136 mmol/L, then again in S for 1 hour, and finally 1 hour in C. The other half of the strips were studied in reverse order, C-S-C-S. The remaining ten biopsies were included in the second part of the study. Response to increasing doses of oxytocin (OT) in solutions S and C was studied. In the first part of the study we calculated AUC, and created phase portrait plots of two different contractions from the same strip, one smooth and one biphasic. In both parts of the study we registered frequency and force of contractions, and described appearance of the contractions.

Results

First part of the study: Mean (median) contractions per hour in C: 8.7 (7.6), in S 14,3 (13). Mean (SD) difference between groups 5.6 (4.2), p = 0.018. Force of contractions in C: 11.8 (10.2) mN, in S: 10.8 (9.2) mN, p = 0.09, AUC increased in S; p = 0.018. Bi-/multiphasic contractions increased from 8% in C to 18% in S, p = 0.001. All changes were reversible in C. Second part of the study: Frequency after OT 1.65 x 10−9 M in C:3.4 (2.9), in S: 3.8 (3.2), difference between groups: p = 0.48. After OT 1.65 x 10−7 M in C: 7.8 (8.9), increase from previous OT administration: p = 0.09, in S: 8.7 (9.0), p = 0.04, difference between groups, p = 0.32. Only at the highest dose of OT dose was there an increase in force of contraction in S, p = 0.05, difference between groups, p = 0.33. Initial response to OT was more frequently bi/multiphasic in S, reaching significance at the highest dose of OT(1.65 x 10−7 M), p = 0.015. when almost all contractions were bi/multiphasic.

Conclusion

Hyponatraemia reversibly increased frequency of contractions and appearance of bi-or multiphasic contractions, that could reduce myometrial contractility. This could explain the correlation of hyponatraemia and instrumental delivery previously observed. Contractions in the hyponatraemic solution more frequently showed initial multiphasic contractions when OT was added in increasing doses. Longer lasting labours carry the risk both of hyponatraemia and OT administration, and their negative interaction could be significant. Further studies should address this possibility.

Klíčová slova:

Biopsy – Electrolytes – Mixtures – Observational studies – Oxytocin – Pilot studies – Solutions – Vasopressin


Zdroje

1. Johansson S, Lindow S, Kapadia H, Norman M. Perinatal water intoxication due to excessive oral intake during labour. Acta Paediatr. 2002;91(7):811–4. Epub 2002/08/31. doi: 10.1080/08035250213218 12200908

2. Valerio E, Fantinato M, Giovannini IA, Baraldi E, Chiandetti L. Severe asymptomatic maternal antepartum hyponatremia leading to neonatal seizures: prevention is better than cure. Matern Health Neonatol Perinatol. 2015;1:25. Epub 2015/01/01. 27057342

3. Moen V, Brudin L, Rundgren M, Irestedt L. Hyponatremia complicating labour—rare or unrecognised? A prospective observational study. BJOG. 2009;116(4):552–61. Epub 2009/01/30. doi: 10.1111/j.1471-0528.2008.02063.x 19175600

4. Kamizaki J, Shimizu K, Nakajyo S, Urakawa N. A comparative study on the contraction induced by high K+/Na+ deficient solution in rat uterus or urinary bladder. Jpn J Pharmacol. 1988;47(2):179–88. Epub 1988/06/01. doi: 10.1254/jjp.47.179 3199594

5. Wray S, Burdyga T, Noble D, Noble K, Borysova L, Arrowsmith S. Progress in understanding electro-mechanical signalling in the myometrium. Acta Physiol (Oxf). 2015;213(2):417–31. Epub 2014/12/03.

6. Sperelakis N, Inoue Y, Ohya Y. Fast Na+ channels and slow Ca2+ current in smooth muscle from pregnant rat uterus. Mol Cell Biochem. 1992;114(1–2):79–89. Epub 1992/09/08. 1281264

7. Reinl EL, Cabeza R, Gregory IA, Cahill AG, England SK. Sodium leak channel, non-selective contributes to the leak current in human myometrial smooth muscle cells from pregnant women. Mol Hum Reprod. 2015;21(10):816–24. Epub 2015/07/03. doi: 10.1093/molehr/gav038 26134120

8. Shmygol A, Blanks AM, Bru-Mercier G, Gullam JE, Thornton S. Control of uterine Ca2+ by membrane voltage: toward understanding the excitation-contraction coupling in human myometrium. Ann N Y Acad Sci. 2007;1101:97–109. Epub 2007/03/03. doi: 10.1196/annals.1389.031 17332087

9. Gullam JE, Blanks AM, Thornton S, Shmygol A. Phase-plot analysis of the oxytocin effect on human myometrial contractility. Eur J Obstet Gynecol Reprod Biol. 2009;144 Suppl 1:S20–4. Epub 2009/03/14.

10. Ekman-Ordeberg G, Hellgren M, Akerud A, Andersson E, Dubicke A, Sennstrom M, et al. Low molecular weight heparin stimulates myometrial contractility and cervical remodeling in vitro. Acta Obstet Gynecol Scand. 2009;88(9):984–9. Epub 2009/08/07. doi: 10.1080/00016340903176818 19657754

11. Garite TJ, Weeks J, Peters-Phair K, Pattillo C, Brewster WR. A randomized controlled trial of the effect of increased intravenous hydration on the course of labor in nulliparous women. Am J Obstet Gynecol. 2000;183(6):1544–8. Epub 2000/12/20. doi: 10.1067/mob.2000.107884 11120525

12. Eslamian L, Marsoosi V, Pakneeyat Y. Increased intravenous fluid intake and the course of labor in nulliparous women. Int J Gynaecol Obstet. 2006;93(2):102–5. Epub 2006/03/18. doi: 10.1016/j.ijgo.2006.01.023 16542657

13. Salamalekis E, Vitoratos N, Kassanos D, Loghis C, Panayotopoulos N, Sykiotis C. A randomized trial of pulsatile vs continuous oxytocin infusion for labor induction. Clin Exp Obstet Gynecol. 2000;27(1):21–3. Epub 2000/04/12. 10758792

14. Cummiskey KC, Gall SA, Dawood MY. Pulsatile administration of oxytocin for augmentation of labor. Obstet Gynecol. 1989;74(6):869–72. Epub 1989/12/01. 2685676

15. Tribe RM, Crawshaw SE, Seed P, Shennan AH, Baker PN. Pulsatile versus continuous administration of oxytocin for induction and augmentation of labor: two randomized controlled trials. Am J Obstet Gynecol. 2012;206(3):230 e1–8. Epub 2011/12/31.

16. Arrowsmith S, Wray S. Oxytocin: its mechanism of action and receptor signalling in the myometrium. J Neuroendocrinol. 2014;26(6):356–69. Epub 2014/06/04. doi: 10.1111/jne.12154 24888645

17. Moritz ML, Ayus JC. Hospital-acquired hyponatremia—why are hypotonic parenteral fluids still being used? Nat Clin Pract Nephrol. 2007;3(7):374–82. Epub 2007/06/27. doi: 10.1038/ncpneph0526 17592470

18. Guideline for the Prevention, Diagnosis and Management of Hyponatraemia in Labour and the Immediate Postpartum Period. The Regulation and Quality Improvement Authority; GAIN Guidelines and Audit Implementation Network. March 2017.

19. Hoorn EJ, Zietse R. Diagnosis and Treatment of Hyponatremia: Compilation of the Guidelines. J Am Soc Nephrol. 2017;28(5):1340–9. Epub 2017/02/09. doi: 10.1681/ASN.2016101139 28174217


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