허혈 및 재관류후 흰쥐 앞정강근과 가자미근에서 나타나는 미세구조와 SOD 활성의 변화 = Ultrastructural Changes in Rat Anterior Tibial and Soleus Muscles Following Graded Periods of Ischemia and Reperfusion

국문 초록 (Abstract)

에너지 획득방법, 당원의 분포, 모세혈관의 분포 및 미세구조의 차이가 나는 백색근육섬유와 적색근육섬유에서 허혈시간에 따라 나타나는 미세구조의 변화와 SOD의 활성변동을 비교 관찰하여 다음과 같은 결과를 얻었다.
1. 앞정강근에서는 2시간 허혈시 사립체에서 바탕질의 전자밀도가 감소하고 사립체능선이 팽대하였고, 재관류 24시간 경과시에는 근육원섬유사이의 거리가 멀어지고 근육세포질세망의 수조와 종말수조가 팽대하였으며 재관류 72시간 경과시에는 정상대조군과 유사한 소견이 나타났다.
2. 가자미근에서 2시간 허혈시 사립체에서는 사렵체바탕질의 전자밀도가 감소하였으며, 재관류 24 시간 경과시는 근육세포질세망의 수조가 팽대하였고, 재관류 72시간 경과시에는 정상대조군과 유사하였다.
3. 4시간 및 6시간 허혈시 미세구조의 변화는 허혈시간과 재관류 시간경과에 따라 심해져 앞정강근에서는 사립체에서 바탕질의 전자밀도가 감소하고 사렵체능선은 불분명하고 소용돌이소체가 나타났으며 근육원섬유 용해와 곤육원섬유괴사가 관찰되었다. 가자미근에서는 근육원섬유에서 근육미세섬유의 배열과 끝가로막이 불규칙해지고 근육세포질세망의 수조가 팽대하였으며 근육원섬유용해가 나타났다.
4. 앞정강근에서 Cu, Zn-및 Mn-SOD 활성은 미약한 흑은 약한 양성반응을 나타내었고, 가자미근에서는 Cu, Zn-SOD는 미약한 양성반응을, Mn-SOD 는 미약한 혹은 약한 양성반응을 나타내었다. 허혈후 Cu, Zn- 및 Mn-SOD 의 활성은 허혈시간이 길수록 더욱 증가하였다.
5. Cu, Zn- 및 Mn-SOD 활성은 2시간 허혈 및 재관류 24 시간 경과시 약간 증가하였으며 72시간 경과시에는 앞정강근과 가자미근에서 정상대조군과 유사하게 나타났다.
6. 4시간 및 6시간 허혈 및 재관류후 두 근육에서 Cu, Zn- 및 Mn-SOD활성은 증가하였다. 두 근육에서 Mn-SOD의 활성변동은 유사하였으나 Cu, Zn- Mn-SOD의 활성증가는 앞정강근보다 가자미근에서 크게 나타났다.
이상의 결과를 종합하면 허혈 및 재관류 손상은 허혈시간과 재관류시간 경과에 따라 심하게 나타났고 가자미근보다 앞정강근에서 심하게 나타났으며, 손상의 차이는 두 근육에서 나타나는 SOD활성변동과 깊은 연관이 있는 것으로 생각된다.

다국어 초록 (Multilingual Abstract)

Skeletal muscles are known to have tolerance to ischemia, but a prolonged ischemia can cause damage to muscular tissues. The ischemia-reperfusion injury results from the oxygen free radicals released by leucocytes and formed by the reaction of hypoxanthine and xanthine oxidase. Superoxide dismutase (SOD), one of major antioxidant enzymes occurring in the various tissues of the body metabolizes or scarvanges the oxygen free radicals.
Although many studies reported difference in tolerance to ischemia and reperfusion between white and red muscles, some other investigators failed in finding such difference.
The present study was performed to examine effects of graded periods of ischemia and reperfusion on the cellular ultrastructure and activity of SOD in white and red muscles. The Sprague-Dawley rats (200~250 g) were used as experimental animals. Under pentobarbita] (50 mg/kg IP) anesthesia, incision was made on lower abdomen and left common iliac artery was occluded by means of a vascular clamp for 2, 4 and 6 hour (hrs). Thereafter, the superficial portion of mid-belly of anterior tibial muscle and soleus muscles were excised at 0, 24 and 72 hrs after onset of reperfusion. The specimens were sectioned into slices, 2 mm in length, 1 mm in width and thickness. Some specimens were prepared for electron microscopic observation and others for determination of SOD activity by using antihuman CU, Zn- and Mn-SOD antibodies.
The results obtained were as follows.
1. In anterior tibial muscle, areas with loose electron-density and dilated cristae were observed in the mitochondria immediately after 2 hrs of ischemia, while widened intermyofibrillar spaces and dilated cisternae of sarcoplasmic reticulum were seen after 2 hrs and 24 hrs reperfusion. When subjected to 2 hrs ischemia and 72 hrs reperfusion, no significant change was found in the cellular ultrastructure.
2. In soleus muscle, electron density was loose in the matrix of mitochondria immediately after 2 hrs of ischemia, while cisternae of sarcoplasmic reticulum were dilalated after 2 hrs of ischemia and 24 hrs reperfusion. Following 2 hrs of ischemia and 72 hrs repeifusion, the electron microscopic findings were similar to those of normal rats.
3. The changes in cellular ultrastructure were more prominent in both the 4 hrs and 6 hrs ischemia groups, in which degree of ultrastructural changes were proportional to duration of reperfusion.
4. In anterior tibial muscle, trace or weak immunoreactivities of Cu, Zn- and Mn-SOD were seen, whereas trace immunoreactivity of Cu, Zn-SOD and trace or weak immunoreactivity of Mn-SOD were observed in soleus muscle.
5. The immunoreactivities of CU, Zn- and Mn-SOD were not altered in 2 hrs ischemic and 72 hrs reperfused group, while they were increased slightly in 2 hrs ischemic and 24 hrs reperfused group.
6. In both muscles, the activity of SOD increased following 4 hrs or 6 hrs ischemia and 24 hrs or 72 hrs reperfusion. The changes in immunoreactivity of Mn-SOD were not different between two muscles, whereas immunoreactivity of Cu, Zn-SOD were higher in anterior tibial muscle.
Consequently, it is suggested that significant ischemia reperfusion injuries are produced after 4 ~ 6 hrs ishemia followed by 24 hrs or 72 hrs reperfusion, that anterior tibial muscle is more susceptible to ischemic reperfusion injury and that the ischemic-reperfusion injury is closely related with activity of SOD.

목차 (Table of Contents)

• 재료 및 방법
• 결과
• 1. 흰쥐 앞정강근과 가자미근의 전자현미경 소견
• 2. 흰쥐 앞정강근과 가자미근의 SOD 활성소견
• 고찰
• 참고문헌
• Legend of Figures
• Abstract