Skip to main content
NCBI home page
British Journal of Pharmacology logoLink to British Journal of Pharmacology
. 1991 Dec;104(4):950–960. doi: 10.1111/j.1476-5381.1991.tb12532.x

Effects of porcine relaxin on contraction, membrane response and cyclic AMP content in rat myometrium in comparison with the effects of isoprenaline and forskolin.

T Osa 1, H Inoue 1, K Okabe 1
PMCID: PMC1908840  PMID: 1687369

Abstract

1. The longitudinal muscle from the uterus of oestrogen-treated rats was quiescent in Mg-free Krebs solution. Electrical stimulation generated phasic contraction, which was depressed to 35% and 18% by 50 mu and 150 mu porcine relaxin, respectively. 2. The phasic contractions were more strongly depressed to 26% by 50 mu relaxin in solution containing 0.6 mM Mg, and the depression lasted for more than 4 h after the removal of relaxin. During the persisting depression, raising the external Ca to 7.5 mM did not restore the contraction, but the contraction was restored by removal of Mg. 3. The depression of the phasic contraction by relaxin, examined in Mg-free solution, was enhanced and reduced by pretreatment of the tissue with 0.6 mM Mg and 0.6 mM Mn, respectively, for about 15 min. In contrast, the depression of contraction by isoprenaline or forskolin was enhanced by pretreatment with either Mg or Mn. 4. The cellular content of cyclic AMP was measured in Krebs solution containing 0.6 mM Mg. The values were 1.24 (pmol mg-1 protein) in control solution, and 2.31 and 1.56 when the tissues were treated with 150 mu relaxin and 10(-9) M isoprenaline, respectively. 5. The cyclic AMP production in response to 10(-7) M forskolin measured in Mg-free solution was enhanced when the tissue was pretreated with either 0.6 mM Mg or Mn for 15 min. The cyclic AMP production in response to 100 mu relaxin was increased when the tissue was pretreated with 0.6 mM Mg, and was unchanged by pretreatment with Mn. The cyclic AMP production in response to 10(-9) M isoprenaline was unchanged by pretreatment with the divalent cations. 6. The membrane potential of the muscle was -60.8 mV in Krebs solution containing 0.3 mM Mg, and electrical stimulation induced an action potential which consisted of spike and plateau components. Application of 150 mu relaxin reduced the duration of the plateau; the contractions were progressively depressed. The resting membrane potential and membrane resistance were unchanged by application of 150 mu relaxin. The membrane was hyperpolarized by 2.8 mV, accompanied by a decrease in membrane resistance, when 10(-9) M isoprenaline was applied. 7. Although there were several differences between the effects of relaxin and isoprenaline, it is probable that some process, which is cyclic AMP-dependent, accelerated by Mg and depressed by Mn, is involved in the depressant action of relaxin on contraction.

Full text

PDF
950

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Abe Y., Tomita T. Cable properties of smooth muscle. J Physiol. 1968 May;196(1):87–100. doi: 10.1113/jphysiol.1968.sp008496. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Adelstein R. S., Eisenberg E. Regulation and kinetics of the actin-myosin-ATP interaction. Annu Rev Biochem. 1980;49:921–956. doi: 10.1146/annurev.bi.49.070180.004421. [DOI] [PubMed] [Google Scholar]
  3. Anwer K., Hovington J. A., Sanborn B. M. Involvement of protein kinase A in the regulation of intracellular free calcium and phosphoinositide turnover in rat myometrium. Biol Reprod. 1990 Nov;43(5):851–859. doi: 10.1095/biolreprod43.5.851. [DOI] [PubMed] [Google Scholar]
  4. Arkinstall S. J., Jones C. T. Influence of pregnancy on G-protein coupling to adenylate cyclase activation in guinea-pig myometrium. J Endocrinol. 1990 Oct;127(1):15–21. doi: 10.1677/joe.0.1270015. [DOI] [PubMed] [Google Scholar]
  5. Bolton T. B. Mechanisms of action of transmitters and other substances on smooth muscle. Physiol Rev. 1979 Jul;59(3):606–718. doi: 10.1152/physrev.1979.59.3.606. [DOI] [PubMed] [Google Scholar]
  6. Bradshaw J. M., Downing S. J., Moffatt A., Hinton J. C., Porter D. G. Demonstration of some of the physiological properties of rat relaxin. J Reprod Fertil. 1981 Sep;63(1):145–153. doi: 10.1530/jrf.0.0630145. [DOI] [PubMed] [Google Scholar]
  7. Braun S., Arad H., Levitzki A. The interaction of Mn2+ with turkey erythrocyte adenylate cyclase. Biochim Biophys Acta. 1982 Jul 12;705(1):55–62. doi: 10.1016/0167-4838(82)90335-1. [DOI] [PubMed] [Google Scholar]
  8. Bülbring E., Tomita T. Catecholamine action on smooth muscle. Pharmacol Rev. 1987 Mar;39(1):49–96. [PubMed] [Google Scholar]
  9. Cech S. Y., Broaddus W. C., Maguire M. E. Adenylate cyclase: the role of magnesium and other divalent cations. Mol Cell Biochem. 1980 Dec 10;33(1-2):67–92. doi: 10.1007/BF00224572. [DOI] [PubMed] [Google Scholar]
  10. Cech S. Y., Maguire M. E. Magnesium regulation of the beta-receptor-adenylate cyclase complex. I. Effects of manganese on receptor binding and cyclase activation. Mol Pharmacol. 1982 Sep;22(2):267–273. [PubMed] [Google Scholar]
  11. Chamley W. A., Parkington H. C. Relaxin inhibits the plateau component of the action potential in the circular myometrium of the rat. J Physiol. 1984 Aug;353:51–65. doi: 10.1113/jphysiol.1984.sp015321. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Chapman R. A., Ellis D. Uptake and loss of manganese from perfused frog ventricles. J Physiol. 1977 Nov;272(2):355–366. doi: 10.1113/jphysiol.1977.sp012048. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Conti M. A., Adelstein R. S. The relationship between calmodulin binding and phosphorylation of smooth muscle myosin kinase by the catalytic subunit of 3':5' cAMP-dependent protein kinase. J Biol Chem. 1981 Apr 10;256(7):3178–3181. [PubMed] [Google Scholar]
  14. Degani H., Shaer A., Victor T. A., Kaye A. M. Estrogen-induced changes in high-energy phosphate metabolism in rat uterus: 31P NMR studies. Biochemistry. 1984 Jun 5;23(12):2572–2577. doi: 10.1021/bi00307a006. [DOI] [PubMed] [Google Scholar]
  15. Higashi K., Fukunaga K., Matsui K., Maeyama M., Miyamoto E. Purification and characterization of myosin light-chain kinase from porcine myometrium and its phosphorylation and modulation by cyclic AMP-dependent protein kinase. Biochim Biophys Acta. 1983 Sep 28;747(3):232–240. doi: 10.1016/0167-4838(83)90102-4. [DOI] [PubMed] [Google Scholar]
  16. Hsu C. J., McCormack S. M., Sanborn B. M. The effect of relaxin on cyclic adenosine 3',5'-monophosphate concentrations in rat myometrial cells in culture. Endocrinology. 1985 May;116(5):2029–2035. doi: 10.1210/endo-116-5-2029. [DOI] [PubMed] [Google Scholar]
  17. Hsu C. J., Sanborn B. M. Relaxin treatment alters the kinetic properties of myosin light chain kinase activity in rat myometrial cells in culture. Endocrinology. 1986 Feb;118(2):499–505. doi: 10.1210/endo-118-2-499. [DOI] [PubMed] [Google Scholar]
  18. Itoh T., Kuriyama H., Nanjo T. Effects of calcium and manganese ions on mechanical properties of intact and skinned muscles from the guinea-pig stomach. J Physiol. 1982 Dec;333:555–576. doi: 10.1113/jphysiol.1982.sp014469. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Keene J. J., Seidel C. L., Bohr D. F. Manganese on calcium flux and norepinephrine-induced tension in arterial smooth muscle. Proc Soc Exp Biol Med. 1972 Apr;139(4):1083–1085. doi: 10.3181/00379727-139-36303. [DOI] [PubMed] [Google Scholar]
  20. Krall J. F., Leshon S. C., Korenman S. G. Phospholipid and guanine nucleotides sensitive properties of the smooth muscle adenylate cyclase catalytic unit. Biochemistry. 1988 Jul 12;27(14):5323–5328. doi: 10.1021/bi00414a056. [DOI] [PubMed] [Google Scholar]
  21. LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
  22. Lategan T. W., Brading A. F. Contractile effects of manganese on taenia of guinea pig cecum. Am J Physiol. 1988 Apr;254(4 Pt 1):G489–G494. doi: 10.1152/ajpgi.1988.254.4.G489. [DOI] [PubMed] [Google Scholar]
  23. Limbird L. E., Hickey A. R., Lefkowitz R. J. Unique uncoupling of the frog erythrocyte adenylate cyclase system by manganese. Loss of hormone and guanine nucleotide-sensitive enzyme activities without loss of nucleotide-sensitive, high affinity agonist binding. J Biol Chem. 1979 Apr 25;254(8):2677–2683. [PubMed] [Google Scholar]
  24. Marshall J. M., Fain J. N. Effects of forskolin and isoproterenol on cyclic AMP and tension in the myometrium. Eur J Pharmacol. 1984 Dec 15;107(1):25–34. doi: 10.1016/0014-2999(84)90087-6. [DOI] [PubMed] [Google Scholar]
  25. Marshall J. M., Kroeger E. A. Adrenergic influences on uterine smooth muscle. Philos Trans R Soc Lond B Biol Sci. 1973 Mar 15;265(867):135–148. doi: 10.1098/rstb.1973.0016. [DOI] [PubMed] [Google Scholar]
  26. Maruta K., Osa T. Augmentation by external Mg ions of beta-adrenoceptor-mediated actions in the longitudinal muscle of rat uterus. Br J Pharmacol. 1989 Mar;96(3):707–717. doi: 10.1111/j.1476-5381.1989.tb11872.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Maruta K., Osa T., Inoue H. Comparison of Mg, Mn, and Co ions affecting the beta-adrenoceptor-mediated membrane response in the guinea-pig taenia caeci. Jpn J Physiol. 1989;39(5):659–671. doi: 10.2170/jjphysiol.39.659. [DOI] [PubMed] [Google Scholar]
  28. Mercado-Simmen R. C., Bryant-Greenwood G. D., Greenwood F. C. Characterization of the binding of 125I-relaxin to rat uterus. J Biol Chem. 1980 Apr 25;255(8):3617–3623. [PubMed] [Google Scholar]
  29. Mercado-Simmen R. C., Bryant-Greenwood G. D., Greenwood F. C. Relaxin receptor in the rat myometrium: regulation by estrogen and relaxin. Endocrinology. 1982 Jan;110(1):220–226. doi: 10.1210/endo-110-1-220. [DOI] [PubMed] [Google Scholar]
  30. Mittag T. W., Tormay A., Podos S. M. Manganous chloride stimulation of adenylate cyclase responsiveness in ocular ciliary process membranes. Exp Eye Res. 1988 Jun;46(6):841–851. doi: 10.1016/s0014-4835(88)80036-8. [DOI] [PubMed] [Google Scholar]
  31. Nakayama S., Tomita T. Depletion of intracellular free Mg2+ in Mg2(+)- and Ca2(+)-free solution in the taenia isolated from guinea-pig caecum. J Physiol. 1990 Feb;421:363–378. doi: 10.1113/jphysiol.1990.sp017949. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Neer E. J. Interaction of soluble brain adenylate cyclase with manganese. J Biol Chem. 1979 Mar 25;254(6):2089–2096. [PubMed] [Google Scholar]
  33. Nishikori K., Weisbrodt N. W., Sherwood O. D., Sanborn B. M. Effects of relaxin on rat uterine myosin light chain kinase activity and myosin light chain phosphorylation. J Biol Chem. 1983 Feb 25;258(4):2468–2474. [PubMed] [Google Scholar]
  34. Osa T. Modification of the mechanical response of the smooth muscles of pregnant mouse myometrium and guinea pig ileum by cadmium and manganese ions. Jpn J Physiol. 1974 Feb;24(1):101–117. doi: 10.2170/jjphysiol.24.101. [DOI] [PubMed] [Google Scholar]
  35. Porter D. G. Myometrium of the pregnant guinea pig: the probable importance of relaxin. Biol Reprod. 1972 Dec;7(3):458–464. doi: 10.1093/biolreprod/7.3.458. [DOI] [PubMed] [Google Scholar]
  36. Porter D. G., Watts A. D. Relaxin and progesterone are myometrial inhibitors in the ovariectomized non-pregnant mini-pig. J Reprod Fertil. 1986 Jan;76(1):205–213. doi: 10.1530/jrf.0.0760205. [DOI] [PubMed] [Google Scholar]
  37. SAWYER W. H., FRIEDEN E. H., MARTIN A. C. In vitro inhibition of spontaneous contractions of the rat uterus by relaxin-containing extracts of sow ovaries. Am J Physiol. 1953 Mar;172(3):547–552. doi: 10.1152/ajplegacy.1953.172.3.547. [DOI] [PubMed] [Google Scholar]
  38. Sakai K., Uchida M. Manganese-induced contraction in K+-depolarized rat uterine smooth muscle. Gen Pharmacol. 1981;12(1):41–45. doi: 10.1016/0306-3623(81)90026-4. [DOI] [PubMed] [Google Scholar]
  39. Schild H. O. The effect of metals on the S-S polypeptide receptor in depolarized rat uterus. Br J Pharmacol. 1969 Jun;36(2):329–349. doi: 10.1111/j.1476-5381.1969.tb09509.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  40. Schwabe C., Steinetz B., Weiss G., Segaloff A., McDonald J. K., O'Byrne E., Hochman J., Carriere B., Goldsmith L. Relaxin. Recent Prog Horm Res. 1978;34:123–211. doi: 10.1016/b978-0-12-571134-0.50008-9. [DOI] [PubMed] [Google Scholar]
  41. Seamon K. B., Padgett W., Daly J. W. Forskolin: unique diterpene activator of adenylate cyclase in membranes and in intact cells. Proc Natl Acad Sci U S A. 1981 Jun;78(6):3363–3367. doi: 10.1073/pnas.78.6.3363. [DOI] [PMC free article] [PubMed] [Google Scholar]
  42. Shibata S. Effects of Mn++ on 45Ca content and potassium-induced contraction of the aortic strip. Can J Physiol Pharmacol. 1969 Sep;47(9):827–829. doi: 10.1139/y69-136. [DOI] [PubMed] [Google Scholar]
  43. Soloff M. S., Grzonka Z. Binding studies with rat myometrial and mammary gland membranes on effects of manganese on relative affinities of receptors for oxytocin analogs. Endocrinology. 1986 Oct;119(4):1564–1569. doi: 10.1210/endo-119-4-1564. [DOI] [PubMed] [Google Scholar]
  44. Somlyo A. V., Woo C. Y., Somlyo A. P. Effect of magnesium on posterior pituitary hormone action on vascular smooth muscle. Am J Physiol. 1966 Apr;210(4):705–714. doi: 10.1152/ajplegacy.1966.210.4.705. [DOI] [PubMed] [Google Scholar]
  45. Szlachter N., O'Byrne E., Goldsmith L., Steinetz B. G., Weiss G. Myometrial inhibiting activity of relaxin-containing extracts of human corpora lutea of pregnancy. Am J Obstet Gynecol. 1980 Mar 1;136(5):584–586. doi: 10.1016/0002-9378(80)91007-8. [DOI] [PubMed] [Google Scholar]
  46. Volker T. T., Viratelle O. M., Delaage M. A., Labouesse J. Radioimmunoassay of cyclic AMP can provide a highly sensitive assay for adenylate cyclase, even at very high ATP concentrations. Anal Biochem. 1985 Feb 1;144(2):347–355. doi: 10.1016/0003-2697(85)90127-7. [DOI] [PubMed] [Google Scholar]
  47. WIQVIST N., PAUL K. G. Inhibition of the spontaneous uterine motility in vitro as a bioassay of relaxin. Acta Endocrinol (Copenh) 1958 Sep;29(1):135–146. doi: 10.1530/acta.0.0290135. [DOI] [PubMed] [Google Scholar]
  48. Weiss G. Relaxin. Annu Rev Physiol. 1984;46:43–52. doi: 10.1146/annurev.ph.46.030184.000355. [DOI] [PubMed] [Google Scholar]

Articles from British Journal of Pharmacology are provided here courtesy of The British Pharmacological Society

RESOURCES