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Effects of hypoxia on mechanical properties of isolated cat papillary muscle

Ding Baochung, Li Yunxia, Yang Luhua

Defiartment of Physiology, Hunan Medical College. Hunan, China

Abstract

The mechanical properties of isolated cat papillary muscle were investigated during hypoxia and after reoxygenation. The results showed that -dT/dt max/T max, one of the relaxation parameters, decreased significantly after 1 min hypoxia, while all the other contraction parameters remained unchanged. -dT/dt max decreased to 16.7% (P<0.01) after 4 min hypoxia, while the time needed for -dT/dt max decreased to the same extent (16.6%, P<0.05) was 7 min. All relaxation parameters changed significantly for a point of 4 min hypoxia, but the changes of contraction parameters were delayed only after 7 min hypoxia. It is concluded that both contraction and relaxation processes of isolated cat papillary muscle are affected by hypoxia, in which the change of relaxation process begins to appear earlier and more prominent than that of contraction process.

Key words: Hyposia;Papillary muscle;Relaxation time;dT/dt max and -dT/dt max/T max

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Citing This Article：

Ding Baochung, Li Yunxia, Yang Luhua. Effects of hypoxia on mechanical properties of isolated cat papillary muscle. Acta Physiol Sin 1985; 37 (3): (in Chinese with English abstract).