Involvement of irisin in passive blood flow restriction for preventing disuse muscle atrophy in rats

The purpose of this study was to determine the effect of blood flow restriction (BFR) without exercise on muscle fibre atrophy by muscle wet weight and muscle relative weight ratio. Furthermore, to confirm the involvement of irisin in BFR by measuring the haemodynamics of irisin, which has an inhibitory effect on muscle atrophy after BFR. Male Wistar rats were assigned to three groups: spontaneous rearing group, tail suspension group and tail suspension plus blood flow restriction group. Soleus muscle wet weight, relative weight ratio, and serum concentrations of irisin were determined after the respective treatments for 6 weeks. The muscle relative weight ratio of the soleus were greater in the tail suspension plus BFR group compared to the tail suspension group (p < .05). Significantly lower serum irisin levels in the tail suspension plus BFR group versus the natural rearing group (p < .05). The effect of blood flow restriction without exercise in preventing the progression of muscle atrophy was confirmed by assessment of muscle dissection. Blood sampling immediately after BFR significantly reduced serum irisin levels in rats whose muscle atrophy was suppressed by BFR, relative to the control group.