Metabolism Of α-actin, Expression Of α-actin MRNA And MHC MRNA Induced By Exhaustive Eccentric Exercise In Skeletal Muscles Of Rats And Effects Of Acupuncture On Them

The purpose of this study is to investigate the changes of a-actin metabolism, a-actin mRNA and MHC isoform mRNA expression in skeletal muscles of rats after one exhaustive eccentric exercise and the effects of acupuncture on them. 130 adult male SD rats were randomly divided into the sedentary group and the exercise group. The rats of the exercise group were again divided into the acupuncture group and non-acupuncture group. According to the sampling time, the exercise group (the acupuncture and non-acupuncture group) was divided into 12 groups, that is the 0 hours, 6 hours, 12 hours, 24 hours, 48 hours and 72 hours groups. In each group there were ten rats. The rats weighting 205 ± 23.3 (mean ± SE) were maintained at 23 ±1 ℃. They were fed in different chests taking food and drink freely. The rats of the exercise group carried out continuous downhill running with the speed of 16m/min for about 4 hours until exhaustion on the animal treadmill (degree -16?). The rats of the acupuncture group were treated with acupuncture immediately after exhaustive eccentric exercise, but those of the sedentary group and the non-acupuncture group were treated without acupuncture. They were the control groups. The blood and muscle samples were taken immediately, 6 hours, 12 hours, 24 hours, 48 hours and 72 hours after exercise. The serum CK and LDH enzyme activities were measured by means of ultraviolet spectroscopy and the contents of G-actin, F-actin and T-actin in skeletal muscles of rats were measured by means of Dnase I assay. The gene expression of a-actin mRNA and MHC isoforms mRNA were determined by using the quantitative reverse transcription PCR technology.It was found in this study that the serum CK reached the peak immediately after exercise, then gradually decreased to the baseline level 48 hours after exercise. But the serum LDH did not reach the peak until 12 hours after exercise and decreased to the baseline 48 hours after exercise as well. There was no significant difference of the changes of serum CK and LDH between the acupuncture groups and the non-acupuncture groups. However, it could be found that the range of the changes of CK and LDH in the acupuncture groups was smaller than that in the non-acupuncture groups.Compared with the sedentary group, there was no remarkable change of T-actin after exercise. The decreased G-actin could be detected only immediately after exercise. The content of F-actin was significantly higher than that of the sedentary group 0-6 hours after exercise, but 12-24 hours afterexercise it decreased to a lower level than that of the sedentary group. A delayed increase of F-actin depolymerization presented after exercise. The F-actin value of the acupuncture group was improved in a lower range than that of the non-acupuncture group 0~6 hours after exercise, but 12-24 hours after exercise it was remarkably higher than those of the non-acupuncture group. It was shown that acupuncture could regulate the F-actin concentration in skeletal muscles of rats after exercise. Furthermore, the regulation might be bilateral. Acupuncture could stop the increase of F-actin delayed depolymerization induced by high loading exercise.The gene expression of a-actin mRNA in skeletal muscles of rats decreased significantly after one exhaustive exercise. The duration of its recovery was longer than 72 hours. It might be that acupuncture accelerated the recovery process of a-actin mRNA expression after exercise.The MHC mRNA expression of the non-acupuncture group was lower than that of the sedentary group 6-12 hours after exercise. There appeared an excess expression of MHC mRNA 48 hours after exercise. The curve of the change of the total MHC mRNA expression in the acupuncture groups was similar to that in the non-acupuncture group. The duration of recovery of the acupuncture group was shorter, the excess expression of MHC mRNA was ahead of time and its range was higher than that in the non-acupuncture group. It was shown that acupuncture could promote the recovery of MHC mRNA expre...