Evans P D
J Physiol. 1985 Sep;366:331-41. doi: 10.1113/jphysiol.1985.sp015801.
Regional differences in the physiological and biochemical responses to octopamine have been investigated in the extensor tibiae muscle of the hind leg of the locust. Octopamine increases the rate of relaxation of twitch tension generated by the slow motoneurone by different amounts in different regions of the muscle. It also increases the amplitude of twitch tension by the same amount in different regions of the muscle. The relaxation rate of fast twitch tension is increased by the same amount in all regions of the muscle innervated by the fast motoneurone. Octopamine also increases cyclic AMP levels by different amounts in different regions of both the extensor muscle and its antagonistic muscle, the flexor tibiae. In both muscles the maximal responses are obtained in the regions of the muscles containing the highest proportions of slow and intermediate muscle fibres as characterized by their contractile and ultrastructural properties. The results are discussed in terms of their functional significance and compared with examples of differential responses of different muscle fibre types in other invertebrate and vertebrate skeletal muscles.
对蝗虫后腿胫节伸肌中章鱼胺的生理生化反应的区域差异进行了研究。章鱼胺可使慢运动神经元产生的抽搐张力的松弛速率在肌肉的不同区域以不同幅度增加。它还可使抽搐张力的幅度在肌肉的不同区域以相同幅度增加。快运动神经元支配的肌肉所有区域的快抽搐张力松弛速率均以相同幅度增加。章鱼胺还可使伸肌及其拮抗肌——胫节屈肌的不同区域的环磷酸腺苷水平以不同幅度增加。在这两块肌肉中，以收缩和超微结构特性为特征，在含有最高比例慢肌纤维和中间肌纤维的肌肉区域获得最大反应。从功能意义方面对结果进行了讨论，并与其他无脊椎动物和脊椎动物骨骼肌中不同肌纤维类型的差异反应实例进行了比较。
