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001-es BibID:BIBFORM046662
035-os BibID:PMID:16051711
Első szerző:Szentesi Péter (élettanász)
Cím:Depression of force production and ATPase activity in different types of human skeletal muscle fibers from patients with chronic heart failure / P. Szentesi, M. A. Bekedam, B. J. van Beek-Harmsen, W. J. van der Laarse, R. Zaremba, A. Boonstra, F. C. Visser, G. J. M. Stienen
Dátum:2005
ISSN:8750-7587
Megjegyzések:Isometric force production and ATPase activity were determined simultaneously in single human skeletal muscle fibers (n = 97) from five healthy volunteers and nine patients with chronic heart failure (CHF) at 20 degrees C. The fibers were permeabilized by means of Triton X-100 (1% vol/vol). ATPase activity was determined by enzymatic coupling of ATP resynthesis to the oxidation of NADH. Calcium-activated actomyosin (AM) ATPase activity was obtained by subtracting the activity measured in relaxing (pCa = 9) solutions from that obtained in maximally activating (pCa = 4.4) solutions. Fiber type was determined on the basis of myosin heavy chain isoform composition by polyacrylamide SDS gel electrophoresis. AM ATPase activity per liter cell volume (+/-SE) in the control and patient group, respectively, amounted to 134 +/- 24 and 77 +/- 9 microM/s in type I fibers (n = 11 and 16), 248 +/- 17 and 188 +/- 13 microM/s in type IIA fibers (n = 14 and 32), 291 +/- 29 and 126 +/- 21 microM/s in type IIA/X fibers (n = 3 and 5), and 325 +/- 32 and 205 +/- 21 microM/s in type IIX fibers (n = 7 and 9). The maximal isometric force per cross-sectional area amounted to 64 +/- 7 and 43 +/- 5 kN/m(2) in type I fibers, 86 +/- 11 and 58 +/- 4 kN/m(2) in type IIA fibers, 85 +/- 6 and 42 +/- 9 kN/m(2) in type IIA/X fibers, and 90 +/- 5 and 59 +/- 5 kN/m(2) in type IIX fibers in the control and patient group, respectively. These results indicate that, in CHF patients, significant reductions occur in isometric force and AM ATPase activity but that tension cost for each fiber type remains the same. This suggests that, in skeletal muscle from CHF patients, a decline in density of contractile proteins takes place and/or a reduction in the rate of cross-bridge attachment of approximately 30%, which exacerbates skeletal muscle weakness due to muscle atrophy.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:Journal of Applied Physiology. - 99 : 6 (2005), p. 2189-2195. -
További szerzők:Bekedam, M. A. Beek-Harmsen, B. J., van Laarse, W. J., van der Zaremba, Ruud Boonstra, A. Visser, F. C. Stienen, Ger J. M.
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001-es BibID:BIBFORM040084
Első szerző:Szentesi Péter (élettanász)
Cím:ATP utilization for calcium uptake and force production in different types of human skeletal muscle fibres / P. Szentesi, R. Zaremba, W. van Mechelen, G. J. M. Stienen
Dátum:2001
ISSN:0022-3751
Megjegyzések:The contractile properties and ATPase activity of skinned human skeletal muscle fibres from vastus lateralis were examined. Fibre types were resolved from single fibre segments by SDS-polyacrylamide gel electrophoresis. ATPase activity was determined by enzymatic coupling of ATP resynthesis to the oxidation of NADH. The partitioning of ATPase activity into (a) calcium-activated activity due to actomyosin (AM) interaction, (b) calcium-activated activity of the sarcoplasmic reticular (SR) calcium pump, and (c) basal (calcium independent) activity was investigated by comparing ATP utilization before and after exposure of the preparations for 30 min to a solution containing 0.5 % Triton X-100, which effectively abolished the SR ATPase activity. Partitioning of ATPase activity was also determined by measuring ATP utilization and force at different concentrations of butanedione monoxime (BDM), which inhibits AM interaction. The results obtained with Triton X-100 and BDM were similar. At saturating Ca2+ concentrations and 20 degrees C, the AM, SR and basal ATPase activities per litre cell volume (+/- S.E.M.) amounted to 46 +/- 4, 51 +/- 4 and 19 +/- 2 muM s-1 in type I fibres (n = 21), 139 +/- 14, 69 +/- 8 and 30 +/- 3 muM s-1 in type IIA fibres (n = 25), 137 +/- 22, 175 +/- 28 and 26 +/- 8 muM s-1 in type IIA/B fibres (n = 4) and 108 +/- 13, 169 +/- 42 and 32 +/- 8 muM s-1 in type IIB fibres (n = 2). These results indicate that ATP utilization for SR Ca2+ pumping in fast fibres is considerably larger than in slow fibres. The SR ATPase activity in human muscle represents a considerable fraction of the total (AM + SR + basal) ATPase activity.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:Journal Of Physiology-London. - 531 : Pt2 (2001), p. 393-403. -
További szerzők:Zaremba, Ruud Mechelen, W. van Stienen, Ger J. M.
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3.

001-es BibID:BIBFORM024550
Első szerző:Szentesi Péter (élettanász)
Cím:Calcium handling by the sarcoplasmic reticulum during oscillatory contraction of skinned skeletal muscle fibres / Péter Szentesi, R. Zaremba, G. J. M. Stienen
Dátum:1998
ISSN:0142-4319
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:Journal Of Muscle Research And Cell Motility. - 19 : 6 (1998), p. 675-687. -
További szerzők:Zaremba, Ruud Stienen, Ger J. M.
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