Kurihara S, Saeki Y, Hongo K, Tanaka E, Sudo N
Department of Physiology, Jikei University School of Medicine, Tokyo, Japan.
Jpn J Physiol. 1990;40(6):915-20. doi: 10.2170/jjphysiol.40.915.
Quick release of the right ventricular papillary muscle of ferrets, injected with aequorin, from Lmax (initial length) to 92% Lmax during twitch response produced an extra-light signal of aequorin. 2,3-Butanedione monoxime (BDM) at 10 mM decreased the peak tension to less than 10% of that in control and the light signal to 70%. In the BDM-treated muscle, the extra-light in response to the quick release did not occur. A quick stretch from Lmax to 103% Lmax, in the presence and absence of BDM, did not cause any changes in the light signal. The results indicate that the extra-light signal in the quick release is tension dependent. The tension reduction by the quick release decreases the affinity of troponin-C (Tn-C) for Ca2+ without affecting Ca2+ handling system in intact cardiac muscle.
给雪貂右心室乳头肌注射水母发光蛋白后，在抽搐反应期间将其从最大长度（初始长度）快速释放至92%最大长度，产生了水母发光蛋白的额外光信号。10 mM的2,3-丁二酮单肟（BDM）使峰值张力降至对照组的不到10%，光信号降至70%。在BDM处理的肌肉中，快速释放时不会出现额外光信号。在有和没有BDM的情况下，从最大长度快速拉伸至103%最大长度，光信号均未发生任何变化。结果表明，快速释放中的额外光信号与张力有关。快速释放导致的张力降低会降低肌钙蛋白C（Tn-C）对Ca2+的亲和力，而不影响完整心肌中的Ca2+处理系统。
