Related Experiment Videos
No increasing injury during early reperfusion of skeletal muscle
K Hvaal1, A Svindland, L Nordsletten
1Institute for Surgical Research, Rikshospitalet (The National Hospital), Oslo, Norway.
Abstract:
Early reperfusion is thought to contribute to the final parenchymal and microvascular injury after transient ischaemia of skeletal muscle. Albumin, a large molecule which is not found in intact cells, can be used as an early marker of extensive membrane injury. In the present study, staining of intracellular albumin was used to test the hypothesis that muscle cell injury increases during early reperfusion. Complete ischaemia was induced for 3 h 15 min in rat hindlimbs. A total of 16 animals were randomized into two groups. The anterior tibial muscles were dissected and fixed in formaldehyde without reperfusion in one group, while circulation was re-established in the hindlimbs for 3 h in the other group. Cross-sections from the muscles were stained with antisera against rat albumin, using fast red as chromogen. This immunostaining showed a central zone of injured cells in each cross-section. The albumin-positive areas, calculated as a percentage of the total cross-sectional areas were 76 and 77% in the two groups respectively. This difference was not significant, suggesting that ischaemia and not reperfusion was the major trauma.
Insights
Skeletal muscle cell injury primarily occurs during ischemia, not reperfusion. Intracellular albumin staining revealed no significant increase in muscle cell damage after reperfusion, indicating ischemia is the main cause of trauma.
Area of Science:
- Biomedical Science
- Skeletal Muscle Physiology
- Ischemia-Reperfusion Injury
Background:
- Transient ischemia can lead to skeletal muscle injury.
- Early reperfusion is a suspected contributor to this injury.
- Albumin influx into cells indicates membrane damage.
Purpose of the Study:
- To investigate if muscle cell injury increases during early reperfusion.
- To test the hypothesis that reperfusion exacerbates ischemia-induced skeletal muscle damage.
Main Methods:
- Induction of 3h 15min hindlimb ischemia in rats.
- Randomization into two groups: no reperfusion and 3h reperfusion.
- Immunohistochemical staining for intracellular albumin in anterior tibial muscles.
Main Results:
- Albumin-positive areas, indicating cell injury, were observed in both groups.
- No significant difference in albumin-positive areas between the ischemia-only and ischemia-reperfusion groups (76% vs 77%).
Conclusions:
- Ischemia, not reperfusion, is the primary cause of skeletal muscle cell injury.
- Intracellular albumin staining is a reliable marker for ischemia-induced muscle damage.