Advertisement

Basic Research in Cardiology

, Volume 80, Issue 3, pp 316–325 | Cite as

Myocellular calcium regulation by the sarcolemmal membrane in the adult and immature rabbit heart

  • R. J. BoucekJr.
  • M. E. Shelton
  • M. Artman
  • E. Landon
  • Rhonda Pettus
Original Contributions

Summary

Previous studies have suggested ontogenic differences in Ca-mediated excitation-contraction coupling in mammalian heart. Sarcolemmal (SL) Ca regulation may predominate prior to the development of the specialized Ca-regulatory properties of the sarcoplasmic reticulum (SR). The effect of development on selected Ca-regulatory properties of cardiac SL was evaluated utilizing membrane vesicles obtained from immature (14 to 21-day-old) and adult rabbit heart.

Methods were adapted to comparably enrich SL membrane vesicles from immature and adult rabbit heart. The global fluidity characteristics were determined by the polarized fluorescence of diphenylhexatriene passively incorporated into enriched SL membrane vesicles. No age-related differences in either the membrane microviscosity of the lipid-order parameter between 10°C and 37°C were observed.

The membrane characteristics of the voltage-gated Ca channel were determined by the membrane binding characteristics of3[H]-nitrendipine. Scatchard analysis of high affinity specific nitrendipine binding demonstrated comparable binding affinity (KD; 511±40 vs 484±40 pM) and theoretical maximal binding site density (Bmax; 218±19 vs 240±40 fmoles/mg prot.) in immature and adult respectively. ATP-independent Ca binding to SL membrane vesicles was determined between 1.5 and 10 mM [Ca]. Ca binding was greater in the immature at 10 mM [Ca] as compared to the adult (840±120 vs 350±30 nmoles/mg). Ca bound to SL over this Ca concentration range is indicative of a “pool” of Ca for cellular influx across the SL by the Na−Ca exchange mechanism and the voltage-gated Ca channel. In view of electrophysiologic evidence also suggesting that Ca-channel-mediated Ca conductance is greater in the immature than the adult, it is proposed that the number of voltage-activatable Ca channels localized to the SL is greater in the immature than the adult. The larger transsarcolemmal Ca fluxes plays a larger role in the beat-to-beat- regulation of cardiac contraction in the developing mammalian heart prior to full expression of the specialized Ca regulatory properties of the SR.

Key words

sarcolemmal membrane preparation calcium binding microviscosity nitrendipine binding 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Avruch J, Wallach DF (1971) Preparation and properties of plasma membrane and endoplasmic reticulum. Biochem Biophys Acta 233:334–347PubMedGoogle Scholar
  2. 2.
    Bers DM (1979) Isolation and characterization of cardiac sarcolemma. Biochem Biophys Acta 555:131–146PubMedGoogle Scholar
  3. 3.
    Bers DM, Philipson KD, Langer GA (1981) Cardiac contractility and sarcolemmal calcium binding in several cardiac muscle preparations. Amer J Physiol 240:H576-H583PubMedGoogle Scholar
  4. 4.
    Boucek JR, Jr, Mushlin PS, Shelton M, Starnes V, Olson RD (1982) Developmental differences of the myocardial contractile response to the calcium antagonists. Ped Res 97AGoogle Scholar
  5. 5.
    Boucek RJ, Jr, Shelton M, Mushlin PS, Olson RD (1983) Comparative effects of Verapamil, Nifedipine and Diltiazem on contractile function in the isolated immature and adult rabbit heart. Ped Res, in pressGoogle Scholar
  6. 6.
    Fabiato A (1982) Calcium release in skinned cardiac cells: Variations with species, tissues, and development. Fed Proc 41:2238–2244PubMedGoogle Scholar
  7. 7.
    Fozzard HA (1977) Heart: Excitation-contraction coupling. Ann Rev Physiol 39:201–220CrossRefGoogle Scholar
  8. 8.
    George BL, Jarmakani JM (1983) The effects of Lanthanum and Manganese on excitation-contraction coupling in the newborn rabbit heart. Dev Pharmacol Ther 6:33–34PubMedGoogle Scholar
  9. 9.
    Hoerter J, Mazet F, Vassort G (1981) Perinatal growth of the rabbit cardiac cell: Possible implications for the mechanism of relaxation. J Mol Cell 13:725–740CrossRefGoogle Scholar
  10. 10.
    Holck M, Thorens S, Haeusler G (1982) Characterization of (3H)-nifedipine binding sites in rabbit myocardium. Eur J Pharm 85:305–315CrossRefGoogle Scholar
  11. 11.
    Kapitulanik J, Tshershedsky M, Barenholz Y (1979) Fluidity of the rat liver microsomal membranes: Increase at birth. Science 206:843–844PubMedGoogle Scholar
  12. 12.
    Kazazoglou T, Schmid A, Renaud JF, Lazdunski M (1983) Ontogenic appearance of Ca channels characterized as binding sites for nitrendipine during developmental of nervous, skeletal and cardiac muscle systems in the rat. FEBS Letters 164:75–79CrossRefPubMedGoogle Scholar
  13. 13.
    Kutchai H, Barenholtz Y, Ross TF, Wermer DE (1976) Developmental changes in plasma membrane fluidity in chick embryo heart. Biochem Biophys Acta 436:101–112PubMedGoogle Scholar
  14. 14.
    Langer GA, Frank JS, Philipson KD (1982) Ultrastructure and calcium exchange of the sarcolemma, sarcoplasmic reticulum and mitochondria of the myocardium. Pharm Ther 16:331–376CrossRefGoogle Scholar
  15. 15.
    Lowry OH, Rosebrough NJ, Farr AL, Randall RJ (1951) Protein measurement with folin phenol reagent. J Biol Chem 193:265–275PubMedGoogle Scholar
  16. 16.
    Maylie JG (1982) Excitation-contraction coupling in neonatal and adult myocardium of cat. Am J Physiol 242:H834-H843PubMedGoogle Scholar
  17. 17.
    Miller RJ, Freedman SB (1984) Are dihydropyridine binding sites voltage sensitive calcium channels? Life Sciences 34:1205–1221CrossRefPubMedGoogle Scholar
  18. 18.
    Morcos NC, Drummond GI (1980) (Ca2++Mg2+)-ATPase in enriched sarcolemma from dog heart. Biochem Biophys Acta 589:27–39Google Scholar
  19. 19.
    Nagatomo T, Hattori K, Ikeda M, Shimada K (1980) Lipid composition of sarcolemma, mitochondria and sarcoplasmic reticulum from newborn, and adult rabbit cardiac muscle. Biochem Med 23:108–118CrossRefPubMedGoogle Scholar
  20. 20.
    Nakanishi T, Jarmakani JM (1984) Developmental changes in myocardial mechanical function and subcellular organelles. Am J Physiol 246:H615-H625PubMedGoogle Scholar
  21. 21.
    Nishioka K, Nakanishi T, George BL, Jarmakani JM (1981) The effect of calcium on the inotropy of catecholamine and paired electrical stimulation in the newborn and adult myocardium. J Mol Cell Card 13:511–520CrossRefGoogle Scholar
  22. 22.
    Page E, Buecker JL (1981) Development of dyadic junctional complexes between sarcoplasmic reticulum and plasmalemma in rabbit left ventricular myocardial cells: Morphometric analysis. Circ Res 48:519–522PubMedGoogle Scholar
  23. 23.
    Quinn P, Briscoe MG, Nuttau A, Smith HJ (1981) Species variation in arterial-myocardial sensitivity to verapamil. Cardiovasc Res 15:398–403PubMedGoogle Scholar
  24. 24.
    Reder RF, Miura DS, Danilo P, Jr, Rosen MR (1981) The electrophysiologic properties of normal neonatal and adult canine cardiac purkinje fibers. Circ Res 48:658–668PubMedGoogle Scholar
  25. 25.
    Reiter M, Vierling W, Seibel K (1984) Where is the origin of the activator calcium in cardiac ventricular contraction. Basic Res Cardiol 79:1–8Google Scholar
  26. 26.
    Shinitzky M, Barenholz Y (1978) Fluidity parameters of lipid regions determined by fluorescence polarization. Biochem Biophys Acta 515:367–394PubMedGoogle Scholar
  27. 27.
    Van Blittersuijk WJ, Van Hoeven RP, Van Der Meer BW (1981) Lipid structural order parameters (reciprocal of fluidity) in biomembranes derived from steady-state fluorescence polarization measurements. Biochem Biophys Acta 664:323–332Google Scholar
  28. 28.
    Winegard S (1982) Calcium release from cardiac sarcoplasmic reticulum. Ann Rev Physiol 44:451–462CrossRefGoogle Scholar

Copyright information

© Dr. Dietrich Steinkopff Verlag 1985

Authors and Affiliations

  • R. J. BoucekJr.
    • 3
    • 1
    • 2
  • M. E. Shelton
    • 3
    • 1
    • 2
  • M. Artman
    • 3
    • 1
    • 2
  • E. Landon
    • 3
    • 1
    • 2
  • Rhonda Pettus
    • 3
    • 1
    • 2
  1. 1.Department of BiochemistryVanderbilt University School of MedicineNashville(U.S.A.)
  2. 2.Department of PharmacologyVanderbilt University School of MedicineNashville(U.S.A.)
  3. 3.Department of PediatricsVanderbilt Medical CenterNashville

Personalised recommendations