| Objective: To establish a rat model of intensive care unit-acquired weakness (ICU-AW) using cecal ligation and puncture (CLP), observe the effects of electroacupuncture (EA) at the "Zusanli" (ST36) acupoint on the pathology and inflammatory cytokines of the gastrocnemius muscle in ICU-AW rats, and explore its effects and potential mechanisms on ICU-AW. Methods: Forty-four male SD rats were randomly divided into a control group (12 rats), a sham operation group (12 rats), a model group (8 rats), and an EA group (8 rats). Both the model group and EA group underwent CLP modeling, while the sham operation group only underwent laparotomy and subsequent closure. After successful modeling, the EA group received daily EA stimulation at bilateral Zusanli points for 30 minutes each time, continuously for 7 days. The survival status of rats in each group was observed after surgery. On the 7th day post-surgery, rats were sacrificed, and gastrocnemius muscle and serum samples were collected. Body weight, wet weight of the gastrocnemius muscle, and muscle reduction index (SI) were measured. HE staining and Masson staining were used to observe the pathological changes in the gastrocnemius muscle. The cross-sectional area (CSA) and collagen volume fraction (CVF) of muscle fibers were measured. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of IL-1β, IL-6, and CRP in serum and gastrocnemius muscle tissue. Results: 1) Compared with the sham operation group, the model group rats exhibited poorer overall condition, weaker resistance to consciousness, and a higher mortality rate (P<0.05). Their body weight, wet weight of gastrocnemius muscle, SI, and CSA all decreased (P<0.05). Serum and gastrocnemius muscle tissue levels of IL-1β, IL-6, CRP, and CVF all increased (P<0.05). Pathological examination revealed phenomena such as muscle fiber atrophy and extensive accumulation of collagen fibers in the gastrocnemius muscle of the rats. 2) Compared with the model group, the electroacupuncture group showed improvements in all the aforementioned indicators, with an increased survival rate (P<0.05). The body weight, wet weight of gastrocnemius muscle, SI, and CSA of the rats were higher than those in the model group (P<0.05). Serum and gastrocnemius muscle tissue levels of IL-1β, IL-6, CRP, and CVF were lower than those in the model group (P<0.05). The degree of gastrocnemius muscle damage and collagen fiber accumulation in the rats was lower than that in the model group. Conclusion: Electroacupuncture at the "Zusanli" acupoint may delay gastrocnemius muscle atrophy in ICU-AW model rats by inhibiting the release of inflammatory cytokines and reducing collagen fiber formation. |