An X-Ray Diffraction Study on Mouse Cardiac Cross-Bridge Function In Vivo: Effects of Adrenergic β-Stimulation
An X-Ray Diffraction Study on Mouse Cardiac Cross-Bridge Function In Vivo: Effects of Adrenergic β-Stimulation
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体内小鼠心脏跨桥功能的 X 射线衍射研究：肾上腺素能 β 刺激的影响
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
N. Yagi
中科院分区：
文献类型：
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作者：
R. Toh;M. Shinohara;Tomofumi Takaya;T. Yamashita;Shigeru Masuda;S. Kawashima;M. Yokoyama;N. Yagi
为了研究β刺激如何影响心肌的收缩性，在体内记录了小鼠心脏左心室游离壁中心肌的X射线衍射。据我们所知，这是第一次对活体心脏进行x射线衍射研究。在心电图R波之后，赤道（1，0）和（1，1）反射的强度比从舒张期的2.1下降到最小值0.8，持续约50 ms，然后恢复。（1，0）晶格面间距在舒张期从37.2nm增加到最大值39.1nm，然后恢复到舒张期水平，对应于肌节伸长约10%。多巴酚丁胺（20 μg/kg/min）刺激β-肾上腺素能受体，可加速强度比的降低，使收缩期强度比减小，并使晶格间距增大。然而，强度比和间距在端孔不变。弛豫过程中的晶格间距的恢复也被加速。在β刺激的心脏中，在收缩期向细丝的质量转移接近于4°C下青蛙骨骼肌抽搐的峰值，表明大多数横桥已经被招募，只有少数保留。
To investigate how β-stimulation affects the contractility of cardiac muscle, x-ray diffraction from cardiac muscle in the left ventricular free wall of a mouse heart was recorded in vivo. To our knowledge, this is the first x-ray diffraction study on a heart in a living body. After the R wave in electrocardiograms, the ratio of the intensities of the equatorial (1,0) and (1,1) reflections decreased for ∼50 ms from a diastolic value of 2.1 to a minimum of 0.8, and then recovered. The spacing of the (1,0) lattice planes increased for ∼90 ms from a diastolic value of 37.2 nm to a maximum of 39.1 nm, and then returned to the diastolic level, corresponding to ∼10% stretch of sarcomere. Stimulation of β-adrenergic receptor by dobutamine (20 μg/kg/min) accelerated both the decrease in the intensity ratio, which reached a smaller systolic value, and the increase in the lattice spacing. However, the intensity ratio and spacing at the end-diastole were unchanged. The recovery of the lattice spacing during relaxation was also accelerated. The mass transfer to the thin filaments at systole in a β-stimulated heart was close to the peak value in twitch of frog skeletal muscle at 4°C, showing that the majority of cross-bridges have been recruited with few in reserve.
影响因子：
4.1
作者：
GARVEY, JL;KRANIAS, EG;SOLARO, RJ
通讯作者：
SOLARO, RJ
大鼠心脏横桥结构与肌动球蛋白 ATP 酶活性的关系。
影响因子：
20.1
作者：
Weisberg,A;Winegrad,S
通讯作者：
Winegrad,S
带皮心脏和骨骼肌束的渗透压：对力产生、Ca2+敏感性和Ca2+结合的影响。
影响因子：
5
作者：
Wang,YP;Fuchs,F
通讯作者：
Fuchs,F