Smooth muscle energetic in the pig coronary artery during a calcium-dependent and a calcium-independent isometric contraction

Article Article scientifique Article Smooth muscle energetic in the pig coronary artery during a calcium-dependent and a calcium-independent isometric contraction eng 1996-12 author Beny Jean-Louis 26368 author Van Der Bent Vincent Joachim 22948 author Decrouy Anne Lucienne Marie 24277 author Chinet Auguste 181-187 10.1016/S0024-3205(96)00614-5 0024-3205 https://linkinghub.elsevier.com/retrieve/pii/S0024320596006145 Heat production by resting smooth muscle, was measured with a heat-flux micro calorimeter on cut-open segments of pig coronary artery superfused at 30 °C, was 0.93 ± 0.06 (n = 16) mWg wet weight. Time courses of the increases in isometric tension and heat production with respect to basal during sustained supra maximal acetylcholine stimulation were qualitatively similar: initial peak tapering down to a supra basal plateau. Mean tension-associated heat production over 1 h was 0.16 Jg. During sustained exposure to phorbol 12, 13-dibutyrate, supra basal tension and - with a 5–10 min initial delay - supra basal heat progressively increased to a plateau in about 40 min. Mean tension-associated heat production over 1 h was only 0.02 Jg with normal extracellular and intracellular mobilizable Ca2 pools, and it was further reduced to 0.01 Jg with depleted Ca2 pools. These results show that the maintenance — if not necessarily the building up - of tension under phorbol 12, 13-dibutyrate does not entail any large dissipation of energy and is not dependent on the presence of normal Ca2+ pools. Calorimetry Phorbol ester Energetics Coronary artery Dewey 590 44 Département de génétique et évolution 162 false Life sciences 60 3 77a92c7c-10ea-44d2-a4bb-3a0103783e4e Article (Published version) Restricted 1-s2.0-S0024320596006145-main.pdf 480594 application/pdf restrictedAccess Faculté des sciences / Section de biologie / Département de génétique et évolution

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Smooth muscle energetic in the pig coronary artery during a calcium-dependent and a calcium-independent isometric contraction	Life sciences			1996	201	0

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Van Der Bent, Vincent Joachim