[Thermogenesis of smooth muscle of lamellibranchs during phasic contraction]
(1962) Archives Internationales de Physiologie et de Biochimie — Vol. 70, n° 2, p. 416-417 (1962)
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- Authors
Maréchal, Georges 
- Abstract
- Anterior byssus retractor (ABRM) in phasic contraction produced over 3 kg/cm² in 20 sec at 18-20C°. In comparison to frog sartorius at 0 C° (about 3 mcal/s/g muscle, Aubert, 1956 pg 19), the heat produced by ABRM is much lower and sizably delayed: its maximum, 0.3 to 0.7 mcal per sec and per g muscle is attained after 3.6 s of stimulation, much later than the maximum velocity of force production. Thus, the activation of ABRM is slow. Similarly to frog sartorius, heat production begins to decrease even before the force is maximum, after 6 to 8 sec of stimulation. The heat production decreases much more than in sartorius, so that the maintenance of force requires a very low thermogenesis (0.1mcal/s/g). 5-hydroxytryptamine (5-HT, 10-7- 10-9) increases force by 15%, but thermogenesis increases up to 65%: in this condition, relaxation occurs rapidly (Twarog, 1954). Heat during relaxation is higher when relaxation is faster as found in presence of 5-HT. This heat is somewhat lower than the elastic work stored in the tensionmeter and in the series elastic elements of muscle (Jewell, 1959).
Citations
Baguet, F., Maréchal, G., & Aubert, X. (1962). [Thermogenesis of smooth muscle of lamellibranchs during phasic contraction]. Archives Internationales de Physiologie et de Biochimie, 70(2), 416-417. https://hdl.handle.net/2078.5/214644 (Original work published 1962)