Effects of Penehyclidine Hydrochloride on the Blood-Brain Barrier and ROCK2, CLDN5, and AQP-4 Expression of Brain Tissue in Rats with Intracerebral Hemorrhage

Abstract: Objective To explore the effects of penehyclidine hydrochloride (PHC) on the blood-brain barrier (BBB) and the expression of Rho associated coiled-coil containing protein kinase 2 (ROCK2), claudin 5 (CLDN5), and aquaporin-4 (AQP-4) in rats with intracerebral hemorrhage (ICH). Methods A total of 100 SD rats were divided into 20 rats/group as the sham group, the ICH group, the PHC-L group (1 mg/kg PHC), the PHC-M group (2 mg/kg PHC), and the PHC-H group (4 mg/kg PHC). The rat model of ICH was established by autologous blood (50 μL) injection method (except for the sham group). After successful modeling, the rats in the PHC-L, PHC-M, and PHC-H groups were intraperitoneally injected with the corresponding doses of PHC. The sham group and the ICH group were injected with an equal amount of 0.9% sodium chloride solution for 7 consecutive days, once a day. The Longa scoring method was used to score the neurological impairment in rats. A transmission electron microscope was used to observe the ultrastructure of BBB. The Evans blue (EB) method was used to evaluate the permeability of BBB and the water content in rat brain tissue was detected. Immunohistochemical staining and western blot were used to detect the expressions of ROCK2, CLDN5, and AQP-4 in brain tissue. Results Compared with the sham group, the neurological impairment score [0 score vs. (2.45±0.48) score], EB content [(9.75±1.01) μg/g vs. (32.07±3.22) μg/g], brain tissue water content [(77.21±0.33) % vs. (80.96±0.45) %], ROCK2 integrated optical density (IOD) [(1.02±0.14)×103 vs.(11.05±0.71)×103] and relative expression (0.39±0.03 vs. 1.43±0.24), AQP-4 IOD [(1.67±0.18)×103 vs. (10.85±0.58)×103] and relative expression (0.60±0.07 vs. 1.69±0.21) increased significantly in the ICH group, while the CLDN5 IOD [(10.83±0.64)×103 vs. (3.02±0.33)×103] and relative expression (1.53±0.20 vs. 0.42±0.06) decreased significantly. Compared with the ICH group, the PHC-L, PHC-M, and PHC-H groups reversed the trend of changes in the aforementioned indicators to varying degrees according to different doses of PHC. Conclusions PHC can ameliorate structural damage to the BBB in ICH rats, potentially through up-regulating the level of CLDN5 and inhibiting the expression of ROCK2 and AQP-4.