UCT/MRC Research Unit for Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, Newlands, South Africa.
J Exp Biol. 2011 Dec 1;214(Pt 23):4041-7. doi: 10.1242/jeb.061572.
The aim of the study was to investigate the skeletal muscle characteristics of black wildebeest (Connochaetes gnou) in terms of fibre type and metabolism. Samples were obtained post mortem from the vastus lateralis and longissimus lumborum muscles and analysed for myosin heavy chain (MHC) content. Citrate synthase (CS), 3-hydroxyacyl co A dehydrogenase (3HAD), phosphofructokinase (PFK), lactate dehydrogenase (LDH) and creatine kinase (CK) activities were measured spectrophotometrically to represent the major metabolic pathways in these muscles. Both muscles had less than 20% MHC I, whereas MHC IIa and MHC IIx were expressed in excess of 50% in the vastus lateralis and longissimus lumborum muscles, respectively. Overall fibre size was 2675±1034 μm(2), which is small compared with other species. Oxidative capacity (CS and 3HAD) in both muscles was high and did not differ from one another, but the longissimus lumborum had significantly (P<0.05) higher PFK, LDH and CK activities. No relationships were observed between fibre type and the oxidative and oxygen-independent metabolic capacity as measured by specific enzyme activities. This study confirms the presence of both fast-twitch fibres and high oxidative capacity in black wildebeest, indicating an animal that can run very fast but is also fatigue resistant.
本研究旨在探讨黑角马（Connochaetes gnou）骨骼肌的纤维类型和代谢特征。从死后的股外侧肌和腰最长肌中取样，并分析肌球蛋白重链（MHC）含量。通过分光光度法测量柠檬酸合酶（CS）、3-羟酰基辅酶 A 脱氢酶（3HAD）、磷酸果糖激酶（PFK）、乳酸脱氢酶（LDH）和肌酸激酶（CK）的活性，以代表这些肌肉中的主要代谢途径。两块肌肉的 MHC I 均低于 20%，而 MHC IIa 和 MHC IIx 在股外侧肌和腰最长肌中的表达均超过 50%。总的纤维大小为 2675±1034 μm(2)，与其他物种相比较小。两块肌肉的氧化能力（CS 和 3HAD）均较高，彼此之间没有差异，但腰最长肌的 PFK、LDH 和 CK 活性显著（P<0.05）更高。纤维类型与特定酶活性测量的氧化和无氧代谢能力之间没有观察到相关性。本研究证实了黑角马既有快肌纤维又有高氧化能力的存在，表明这是一种能够跑得非常快但又不易疲劳的动物。
