Błachnio-Zabielska Agnieszka, Baranowski Marcin, Zabielski Piotr, Górski Jan
Department of Physiology, Medical University of Bialystok, Białystok, Poland.
J Cell Biochem. 2008 Oct 15;105(3):776-84. doi: 10.1002/jcb.21877.
Ceramide is the key compound on crossroads of sphingolipid metabolism. The content and composition of ceramides in skeletal muscles have been shown to be affected by prolonged exercise. The aim of this study was to examine the effect of exercise on the activity of key enzymes of ceramide metabolism in skeletal muscles. The experiments were carried out on male Wistar rats (200-250 g) divided into four groups: sedentary, exercised for 30 min, 90 min, and until exhaustion. The activity of serine palmitoyltransferase (SPT), neutral and acid sphingomyelinase (nSMase and aSMase), neutral and alkaline ceramidases (nCDase and alCDase) and the content of ceramide, sphingosine, sphinganine and sphingosine-1-phosphate were determined in three types of muscle. We have found that the activity and expression of SPT increase gradually in each muscle with duration of exercise. These changes were followed by elevation in the content of sphinganine. These data indicate that exercise increases de novo synthesis of ceramide. The aSMase activity gradually decreased with duration of exercise in each type of muscle. After exhaustive exercise the activity of both isoforms of ceramidase were reduced in each muscle. The ceramide level depends both on duration of exercise and muscle type. The ceramide level in the soleus and white gastrocnemius decreased after 30 min of running. After exhaustive exercise it was elevated in the soleus and red gastrocnemius. It is concluded that exercise strongly affects the activity of key enzymes involved in ceramide metabolism and in consequence the level of sphingolipid intermediates in skeletal muscles.
神经酰胺是鞘脂代谢交叉点上的关键化合物。研究表明，长时间运动会影响骨骼肌中神经酰胺的含量和组成。本研究旨在探讨运动对骨骼肌中神经酰胺代谢关键酶活性的影响。实验选用雄性Wistar大鼠（200 - 250克），分为四组：久坐组、运动30分钟组、运动90分钟组和运动至力竭组。测定了三种类型肌肉中丝氨酸棕榈酰转移酶（SPT）、中性和酸性鞘磷脂酶（nSMase和aSMase）、中性和碱性神经酰胺酶（nCDase和alCDase）的活性以及神经酰胺、鞘氨醇、二氢鞘氨醇和鞘氨醇-1-磷酸的含量。我们发现，随着运动时间的延长，每种肌肉中SPT的活性和表达逐渐增加。这些变化之后是二氢鞘氨醇含量的升高。这些数据表明运动增加了神经酰胺的从头合成。在每种类型的肌肉中，aSMase活性随着运动时间的延长而逐渐降低。力竭运动后，每种肌肉中两种神经酰胺酶同工型的活性均降低。神经酰胺水平既取决于运动时间，也取决于肌肉类型。跑步30分钟后，比目鱼肌和白色腓肠肌中的神经酰胺水平降低。力竭运动后，比目鱼肌和红色腓肠肌中的神经酰胺水平升高。结论是，运动强烈影响参与神经酰胺代谢的关键酶的活性，进而影响骨骼肌中鞘脂中间体的水平。
