TY - JOUR
T1 - Endothermic force generation, temperature-jump experiments and effects of increased [MgADP] in rabbit psoas muscle fibres
AU - Coupland, M.E.
AU - Pinniger, Gavin
AU - Ranatunga, K.W.
PY - 2005
Y1 - 2005
N2 - We studied, by experiment and by kinetic modelling, the characteristics of the force increase on heating (endothermic force) in muscle. Experiments were done on maximally Ca2+-activated, permeabilized, single fibres (length ∼2 mm; sarcomere length, 2.5 μm) from rabbit psoas muscle; [MgATP] was 4.6 mm, pH 7.1 and ionic strength was 200 mm. A small-amplitude (∼3°C) rapid laser temperature-jump (0.2 ms T-jump) at 8–9°C induced a tension rise to a new steady state and it consisted of two (fast and slow) exponential components. The T-jump-induced tension rise became slower as [MgADP] was increased, with half-maximal effect at 0.5 mm[MgADP]; the pre- and post-T-jump tension increased ∼20% with 4 mm added [MgADP]. As determined by the tension change to small, rapid length steps (
AB - We studied, by experiment and by kinetic modelling, the characteristics of the force increase on heating (endothermic force) in muscle. Experiments were done on maximally Ca2+-activated, permeabilized, single fibres (length ∼2 mm; sarcomere length, 2.5 μm) from rabbit psoas muscle; [MgATP] was 4.6 mm, pH 7.1 and ionic strength was 200 mm. A small-amplitude (∼3°C) rapid laser temperature-jump (0.2 ms T-jump) at 8–9°C induced a tension rise to a new steady state and it consisted of two (fast and slow) exponential components. The T-jump-induced tension rise became slower as [MgADP] was increased, with half-maximal effect at 0.5 mm[MgADP]; the pre- and post-T-jump tension increased ∼20% with 4 mm added [MgADP]. As determined by the tension change to small, rapid length steps (
U2 - 10.1113/jphysiol.2005.090084
DO - 10.1113/jphysiol.2005.090084
M3 - Article
SN - 0022-3751
VL - 567
SP - 471
EP - 492
JO - The Journal of Physiology
JF - The Journal of Physiology
IS - 2
ER -