Early treadmill exercise decreases intrastriatal hemorrhage-induced neuronal cell death and increases cell proliferation in the dentate gyrus of streptozotocin-induced hyperglycemic rats

Intracerebral hemorrhage (ICH) is a severe complication in diabetic patients. Currently, physical exercise is recommended as a behavioral intervention to promote functional recovery in brain diseases, including ICH. Recently, hyperglycemia is known to aggravate brain injury in experimental ICH. Here, we examined the effect of treadmill exercise on the intrastriatal hemorrhage-induced neuronal cell death and cell proliferation in the dentate gyrus of hyperglycemic rats. Hyperglycemia was induced by the intraperitoneal injection of 50 mg/kg streptozotocin (STZ). Intrastriatal hemorrhage was induced by the infusion of 0.2 U collagenase into the striatum using stereotaxic instrument. Rats in the exercise groups were forced to run on a treadmill for 30 min daily for 10 days. Apoptosis was assessed by the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. Cell proliferation was assessed by the 5-bromo-2′-deoxyuridine (BrdU) immunohistochemistry. Our data showed that in rats started treadmill exercise 24 h after ICH induction, the size of lesion induced by hemorrhage and the number of apoptotic cells were decreased significantly. The number of proliferating cells in the dentate gyrus was significantly decreased in hyperglycemic rats. Treadmill exercise markedly enhanced cell proliferation in the dentate gyrus of hyperglycemic rats. The data suggest that treadmill exercise may provide therapeutic value to ICH patients with hyperglycemia by suppressing neuronal apoptosis and increasing cell proliferation.