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Impaired muscle Ca2+ and K+ regulation contribute to poor exercise performance post-lung transplantation.
J Appl Physiol (1985). 2003 Oct; 95(4):1606-16.JA

Abstract

Lung transplant recipients (LTx) exhibit marked peripheral limitations to exercise. We investigated whether skeletal muscle Ca2+ and K+ regulation might be abnormal in eight LTx and eight healthy controls. Peak oxygen consumption and arterialized venous plasma [K+] (where brackets denote concentration) were measured during incremental exercise. Vastus lateralis muscle was biopsied at rest and analyzed for sarcoplasmic reticulum Ca2+ release, Ca2+ uptake, and Ca2+-ATPase activity rates; fiber composition; Na+-K+-ATPase (K+-stimulated 3-O-methylfluorescein phosphatase) activity and content ([3H]ouabain binding sites); as well as for [H+] and H+-buffering capacity. Peak oxygen consumption was 47% less in LTx (P < 0.05). LTx had lower Ca2+ release (34%), Ca2+ uptake (31%), and Ca2+-ATPase activity (25%) than controls (P < 0.05), despite their higher type II fiber proportion (LTx, 75.0 +/- 5.8%; controls, 43.5 +/- 2.1%). Muscle [H+] was elevated in LTx (P < 0.01), but buffering capacity was similar to controls. Muscle 3-O-methylfluorescein phosphatase activity was 31% higher in LTx (P < 0.05), but [3H]ouabain binding content did not differ significantly. However, during exercise, the rise in plasma [K+]-to-work ratio was 2.6-fold greater in LTx (P < 0.05), indicating impaired K+ regulation. Thus grossly subnormal muscle calcium regulation, with impaired potassium regulation, may contribute to poor muscular performance in LTx.

Authors+Show Affiliations

McKenna MJ
School of Human Movement, Recreation and Performance (FO22 Victoria Univ. of Technology, P.O. Box 14428, MCMC, Melbourne, Melbourne, Victoria 8001, Australia. michael.mckenna@vu.edu.au
Fraser SF
No affiliation info available
Li JL
No affiliation info available
Wang XN
No affiliation info available
Carey MF
No affiliation info available
Side EA
No affiliation info available
Morton J
No affiliation info available
Snell GI
No affiliation info available
Kjeldsen K
No affiliation info available
Williams TJ
No affiliation info available

MeSH

AdultCalciumCalcium-Transporting ATPasesCase-Control StudiesFemaleHumansHydrogen-Ion ConcentrationLung TransplantationMaleMuscle, SkeletalOsmolar ConcentrationOuabainOxygen ConsumptionPhysical FitnessPostoperative PeriodPotassiumSarcoplasmic ReticulumSodium-Potassium-Exchanging ATPase

Pub Type(s)

Journal Article

Language

eng

PubMed ID

12807900

Citation

McKenna, Michael J., et al. "Impaired Muscle Ca2+ and K+ Regulation Contribute to Poor Exercise Performance Post-lung Transplantation." Journal of Applied Physiology (Bethesda, Md. : 1985), vol. 95, no. 4, 2003, pp. 1606-16.
McKenna MJ, Fraser SF, Li JL, et al. Impaired muscle Ca2+ and K+ regulation contribute to poor exercise performance post-lung transplantation. J Appl Physiol (1985). 2003;95(4):1606-16.
McKenna, M. J., Fraser, S. F., Li, J. L., Wang, X. N., Carey, M. F., Side, E. A., Morton, J., Snell, G. I., Kjeldsen, K., & Williams, T. J. (2003). Impaired muscle Ca2+ and K+ regulation contribute to poor exercise performance post-lung transplantation. Journal of Applied Physiology (Bethesda, Md. : 1985), 95(4), 1606-16.
McKenna MJ, et al. Impaired Muscle Ca2+ and K+ Regulation Contribute to Poor Exercise Performance Post-lung Transplantation. J Appl Physiol (1985). 2003;95(4):1606-16. PubMed PMID: 12807900.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Impaired muscle Ca2+ and K+ regulation contribute to poor exercise performance post-lung transplantation. AU - McKenna,Michael J, AU - Fraser,Steve F, AU - Li,Jia L, AU - Wang,Xiao N, AU - Carey,Michael F, AU - Side,Eleonora A, AU - Morton,Judith, AU - Snell,Gregory I, AU - Kjeldsen,Keld, AU - Williams,Trevor J, Y1 - 2003/06/13/ PY - 2003/6/17/pubmed PY - 2004/4/29/medline PY - 2003/6/17/entrez SP - 1606 EP - 16 JF - Journal of applied physiology (Bethesda, Md. : 1985) JO - J Appl Physiol (1985) VL - 95 IS - 4 N2 - Lung transplant recipients (LTx) exhibit marked peripheral limitations to exercise. We investigated whether skeletal muscle Ca2+ and K+ regulation might be abnormal in eight LTx and eight healthy controls. Peak oxygen consumption and arterialized venous plasma [K+] (where brackets denote concentration) were measured during incremental exercise. Vastus lateralis muscle was biopsied at rest and analyzed for sarcoplasmic reticulum Ca2+ release, Ca2+ uptake, and Ca2+-ATPase activity rates; fiber composition; Na+-K+-ATPase (K+-stimulated 3-O-methylfluorescein phosphatase) activity and content ([3H]ouabain binding sites); as well as for [H+] and H+-buffering capacity. Peak oxygen consumption was 47% less in LTx (P < 0.05). LTx had lower Ca2+ release (34%), Ca2+ uptake (31%), and Ca2+-ATPase activity (25%) than controls (P < 0.05), despite their higher type II fiber proportion (LTx, 75.0 +/- 5.8%; controls, 43.5 +/- 2.1%). Muscle [H+] was elevated in LTx (P < 0.01), but buffering capacity was similar to controls. Muscle 3-O-methylfluorescein phosphatase activity was 31% higher in LTx (P < 0.05), but [3H]ouabain binding content did not differ significantly. However, during exercise, the rise in plasma [K+]-to-work ratio was 2.6-fold greater in LTx (P < 0.05), indicating impaired K+ regulation. Thus grossly subnormal muscle calcium regulation, with impaired potassium regulation, may contribute to poor muscular performance in LTx. SN - 8750-7587 UR - https://www.unboundmedicine.com/medline/citation/12807900/Impaired_muscle_Ca2+_and_K+_regulation_contribute_to_poor_exercise_performance_post_lung_transplantation_ DB - PRIME DP - Unbound Medicine ER -