X-RAY DIFFRACTION STUDIES OF FLIGHT MUSCLE OF MANDUCA

曼杜卡飞行肌的 X 射线衍射研究

• 批准号: 8168627
• 负责人: THOMAS C IRVING
• 金额: $ 2.15万
• 依托单位: ILLINOIS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-01-01 至 2010-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8168627
• 关键词: Chemicals; Computer Retrieval of Information on Scientific Projects Database; Fiber; Funding; Generations; Grant; Heat Losses; Heating; High temperature of physical object; Insecta; Institution; Lead; Manduca; Manduca sexta; Mechanics; Muscle; Muscle Contraction; Myocardium; Output; Research; Research Personnel; Resources; Source; Temperature; Testing; Thermogenesis; United States National Institutes of Health; Work; cold temperature; experience; interest

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The flight muscle of the Hawkmoth Manduca sexta is interesting for two reasons 1) It's active force/extension curve in very similar to mammalian cardiac muscle 2) there is an astonishing temperature gradient in the dorso-ventral direction, with a mean difference of 8.8 ¿C (a max of 10 ¿C; n = 7) across 5 mm. It is known that during muscle contraction, heat is produced as chemical energy is converted into mechanical work. Many large insects with active flight muscles use this byproduct to elevate flight muscle temperature, thereby achieving higher mechanical power output during flight. Contractile heat production paired with convective and radiative heat loss necessarily lead to a temperature gradient, but the functional consequences of such a gradient remain unknown. Because force generation of muscle depends on temperature, subunits experiencing lower temperatures could function differently than those at higher temperatures. Do thermal gradients necessarily imply fundamental structural differences between fibers in different parts of muscle? Test the hypothesis that crossbridges in cold muscle do not detach rapidly as rapidly as in hot muscle. i.e. detachment rate a temperature dependent phenomenon. The attachment/detachment rates of crossbridges will also depend on elastic storage in a given muscle.

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 天蛾的飞行肌肉很有趣，原因有二：1）它的主动力/伸展曲线与哺乳动物的心肌非常相似; 2）在背腹方向有一个惊人的温度梯度，平均差异为8.8摄氏度。（最大10 º C; n = 7）。已知在肌肉收缩期间，当化学能转化为机械功时产生热量。许多具有活跃飞行肌肉的大型昆虫使用这种副产品来提高飞行肌肉温度，从而在飞行期间实现更高的机械功率输出。收缩产热与对流和辐射热损失相结合必然导致温度梯度，但这种梯度的功能后果仍然未知。由于肌肉的力量产生取决于温度，经历较低温度的亚基可能与那些在较高温度下的亚基功能不同。温度梯度是否必然意味着肌肉不同部位纤维之间的基本结构差异？测试冷肌中的横桥不像热肌中的横桥那样快速分离的假设。即脱离速率是温度依赖性现象。横桥的附着/分离率还取决于给定肌肉中的弹性储存。