Electroacupuncture at Zusanli (ST36) accelerates intracerebral hemorrhage-induced angiogenesis in rats

To investigate the effects of electro-acupuncture on intracerebral hemorrhage (ICH)-induced angiogenesis and hypoxia-inducible factor-1α (HIF-1α) expression in rats.

Adult male Sprague-Dawley rats were randomly divided into 4 groups of 24 rats each. ICH was induced in 3 groups by stereotactic injection of collagenase type VII into the right globus pallidus; of these, one group was not further treated, the second group underwent Zusanli (ST36)-acupuncture, and the third group underwent non-acupoint acupuncture. The fourth group underwent sham operations. Acupuncture was performed by stimulation with electrical needles at frequencies of 2-20 Hz for 30 min per day. Angiogenesis on days 3, 7 and 14 was assessed by double immunolabeling, and expression of HIF-1α was evaluated by immunohistochemistry, quantitative real time reverse transcription-polymerase chain reaction and Western blotting.

5-Bromo-2-deoxyuridine (BrdU)-labeled nuclei in cerebral endothelial cells (ECs) resided around the hematoma and the labeling peaked from 7 to 14 days (P<0.01). HIF-1α positive microvessels with a dilated outline were detected in perihematomal tissues after ICH, with the vessels extending into the clot from the surrounding area beginning on day 7. Following ICH, HIF-1α protein levels increased (P<0.05), but HIF-1α mRNA levels did not change. Electro-acupuncture at the Zusanli (ST36) acupoint increased BrdU-labeled nuclei in cerebral ECs (P<0.05) and up-regulated the expression of HIF-1α protein (P<0.05), but had little effect on the spatial distribution of HIF-1α or on HIF-1α mRNA levels.

Electro-acupuncture treatment at the Zusanli (ST36) acupoint may accelerate ICH-induced angiogenesis by up-regulating HIF-1α protein, and may enhance recovery following hemorrhagic cerebral injury.