Attenuation of cardiac ischemia/reperfusion injury by transient low hydroperoxide pretreatment in rat / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate how transient low dose of hydroperoxide pretreatment prevents cardiac ischemia/reperfusion injury.</p><p><b>METHODS</b>SD rats were divided into 4 groups: sham operation (Sham), standard ischemia/reperfusion (I/R), ischemic preconditioning (IPC) and IR preceded by low H2O2 treatment. Cardiac function and injury parameter were compared among groups.</p><p><b>RESULTS</b>IPC protected reperfusion injury and improved cardiac function. Low H2O2 treatment played a role in cardioprotection similar to IPC. Low H2O2 was indeed generated in the early phase of simulated ischemia and attenuated cytochrome c release induced by high Ca2+ in isolated mitochondria.</p><p><b>CONCLUSION</b>Low H2O2 plays a critical role in cardioprotection probably by inhibiting mitochondrial permeability transition.</p>

Dorsal root reflex from Adelta and C afferent fibers induced by electrical stimulation of the sural nerve in rats / 生理学报

The purpose of the study was to investigate whether the small fiber-evoked dorsal root reflex (DRR) can be obtained by electrical stimulation of the peripheral nerve in rats. Fifty-one DRRs were recorded from different kinds of fiber filaments in the proximal ends of the cut L(5) dorsal root following electrical stimulation of the sural nerve. According to the kind of afferent fibers in the sural nerve associated with the DRRs from dorsal root, these DRRs were divided into five different types: A(alphabeta) fiber-evoked A(alphabeta).DRR (A(alphabeta)- A(alphabeta).DRR), A(betadelta) - A(delta ).DRR, A(betadelta)-C.DRR, A(alphabetadelta)-C.DRR and C-C.DRR. The results obtained show that the DRR can be obtained from either A-fibers (including A(delta )-fibers) or C-fibers of dorsal root filaments by stimulation of the sural nerve. It is therefore suggested that either A(delta ).DRR or C.DRR can be used as a validity index of presynaptic inhibition of the thin primary afferent terminals for investigation of the modulation mechanisms of peripheral effectors.