ArticleThe Journal of physiology2006
ATP splitting by half the cross-bridges can explain the twitch energetics of mouse papillary muscle.
Article in The Journal of physiology, 2006. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 10 papers.
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Who cites it
10 citing papers in PubMed, 17 citations in OpenAlex.
- Cardiac mechanical efficiency is preserved in primary cardiac hypertrophy despite impaired mechanical function.The Journal of general physiology · 2021Article
- A dilated cardiomyopathy mutation blunts adrenergic response and induces contractile dysfunction under chronic angiotensin II stress.American journal of physiology. Heart and circulatory physiology · 2015Article
- Contractile apparatus dysfunction early in the pathophysiology of diabetic cardiomyopathy.World journal of diabetes · 2015Review
- Mechanical and energetic properties of papillary muscle from ACTC E99K transgenic mouse models of hypertrophic cardiomyopathy.American journal of physiology. Heart and circulatory physiology · 2013Article
- Quantifying Ca2+ release and inactivation of Ca2+ release in fast- and slow-twitch muscles.The Journal of physiology · 2012Article
- Paying the piper: the cost of Ca2+ pumping during the mating call of toadfish.The Journal of physiology · 2011Article
- Regional variation in myofilament length-dependent activation.Pflugers Archiv : European journal of physiology · 2011Review
- A reconsideration of the link between the energetics of water and of ATP hydrolysis energy in the power strokes of molecular motors in protein structures.International journal of molecular sciences · 2008Article
- Effects of sustained length-dependent activation on in situ cross-bridge dynamics in rat hearts.Biophysical journal · 2007Article
- Energetics of small hearts.The Journal of physiology · 2006Review
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Authors and funding
2 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
The aim of this study was to quantify the fraction of cross-bridges that cycle during a cardiac twitch. Measurements of the energetics of contracting left ventricular mouse papillary muscle were made in vitro (27 degrees C) using the myothermic technique. Enthalpy output was partitioned into force-dependent and force-independent components using 2,3-butanedione monoxime (BDM) to selectively inhibit cross-bridge cycling. For isometric contractions and a contraction frequency of 2 Hz the net enthalpy output was 5.7 +/- 0.8 mJ g(-1) twitch(-1) and initial enthalpy output was 2.3 +/- 0.3 mJ g(-1) twitch(-1) (n = 11). Assuming that low concentrations of BDM did not affect Ca2+ cycling, force-independent enthalpy output was 18.6 +/- 1.9% (n = 7) of the initial enthalpy output. Enthalpy output decreased with increased contraction frequency but was independent of shortening velocity. On the basis of these values, it was calculated that the twitch energetics were consistent with ATP splitting by half the cross-bridges and the pumping of one Ca2+ into the sarcoplasmic reticulum for every three cross-bridge cycles. The simplest interpretation is that half the cross-bridges completed one ATP-splitting cycle in each twitch. The lack of influence of shortening velocity on energy cost supports the idea that the amount of energy to be used is determined early in a twitch and is not greatly influenced by events that occur during the contraction.
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