The effects of fibroblast growth factor-2 and pluripotent astrocytic stem cells on cognitive function in a rat model of neonatal hypoxic-ischemic brain injury.

OBJECTIVE: This study aimed to determine the effect of pluripotent astrocytic stem cells (PASCs) and fibroblast growth factor-2 (FGF-2) on cognitive function in neonatal rats with hypoxic-ischemic brain injury (HIBI). METHODS: The study was performed on 7-d-old rats that were randomly divided into four groups. All rats, except those in the sham group, were kept in a hypoxic chamber containing 8% oxygen for 2 h after the ligation of the right carotid artery. Next, 5 d after HIBI was induced, PASCs were administered to the motor cortex, and FGF-2 was administered intraperitoneally to group AF; PASCs were administered to the motor cortex, and salt solution buffered with phosphate was administered intraperitoneally to group A; and fresh cell culture solution (medium) was administered to group M. Immunofluorescence was used to localize the administered PASCs in the brains of rats from groups A and AF. The Morris water maze tank (MWM) test was performed to assess the rats' cognitive functions at week 12. The rats that were administered PASCs were observed for the development of neoplasms and autopsies were performed after 30 months. RESULTS: PASCs migrated to damaged brain regions surrounding the hippocampus in groups A and AF. The mean platform finding time (PFT) significantly decreased over time in each group on day 1-4 of MWM testing (p < 0.001). On day 2-4, the mean PFT was shortest in group S followed by group AF. In group A, the PFT was significantly longer than in group S on day 3-4 (p = 0.01 and 0.007, respectively). On day 5 of the MWM test, the time spent in the eastern quadrant (which previously contained the platform) was longest in group S followed by groups AF, A, and M; however, the differences between groups were not significant (p = 0.51). After 30 months, none of the rats in groups A or AF had benign or malignant neoplasms. CONCLUSIONS: Following the administration of PASCs in rats with experimentally induced HIBI, PASCs migrated to the injured brain regions; however, treatment with PASCs did not have a positive effect on cognitive function. The administration of FGF-2 together with PASCs resulted in positive cognitive results, although not at the level of significance.

Rho-kinase levels in testicular ischemia-reperfusion injury and effects of its inhibitor, Y-27632, on oxidative stress, spermatogenesis, and apoptosis.

OBJECTIVE: To investigate testicular Rho-kinase levels and the effects of its inhibitor, Y-27632, on oxidative stress, spermatogenesis, and apoptosis in testicular ischemia-reperfusion rat model. METHODS: The study included 29 adult Wistar-Albino male rats weighing 150-200 g. The rats were divided into 3 groups. Group 1 underwent sham operation (n = 10). In group 2, left testicular torsion-detorsion was performed (n = 9). In group 3, Rho-kinase inhibitor Y-27632 (5 mg/kg) was injected intraperitoneally 30 minutes before detorsion (n = 10). Two months later, bilateral orchiectomy was performed in all the groups. Rho-kinase levels by Western blotting, apoptosis with terminal deoxynucleotidyl transferase dUTP nick end labeling method, testicular damage and spermatogenesis with modified Johnsen score, testicular total antioxidative status, and total oxidative status were measured. RESULTS: In the torsion-detorsion (T/D) group, Rho-kinase level increased significantly, compared with the sham group (P = .025). In the Y-27632 treatment group, Johnsen scores were significantly higher, and apoptosis indexes were significantly lower, compared with the T/D group (P = .001). Significantly higher total antioxidative status levels and lower total oxidative status levels were observed in the Y-27632 treatment group, compared with the T/D group (P = .001 and P = .002, respectively). CONCLUSION: Testicular ischemia-reperfusion significantly increased Rho-kinase levels in rats, and administration of Rho-kinase inhibitor, Y-27632, before detorsion might prevent ischemia-reperfusion injury.

Role of Rho-kinase in contractions of ureters from rabbits with unilateral ureteric obstruction.

OBJECTIVE: To investigate the expression of two isoforms of Rho-kinase (ROCK) and its functional role in the pathophysiological control of smooth muscle contraction in rabbits with unilateral ureteric obstruction (UUO). MATERIAL AND METHODS: Left UUO was created in 14 rabbits and eight other rabbits (controls) had sham operations. After 2 weeks all the rabbits were killed. Ureteric strips suspended in an organ bath were used for functional studies and the effects of Y-27632, a specific inhibitor of Rho-kinase, on spontaneous contractions and electrical field stimulation (EFS; 50 V, 1 ms, 16 Hz, for 20 s), carbachol- (10(-7)-10(-4)m), phenylephrine- (10(-7)-10(-4)m) and KCl- (50 mm) induced contractions were analysed. Western blotting was used to determine expression levels of Rho-kinase protein in the ureters of UUO and control rabbits. RESULTS: In the functional analysis, the contractions induced by EFS, KCl, phenylephrine and carbachol in the ureteric strips from rabbits with UUO were significantly greater than those from the control rabbits. Y-27632 considerably suppressed the ureter contractile responses in both UUO and control rabbits. Western blot analysis showed that both ROCK-1 and ROCK-2 proteins were expressed in the rabbit ureter. In accordance with the functional studies, the expression levels of both ROCK-1 and ROCK-2 were significantly greater in the ureters of UUO rabbits than in the controls. CONCLUSIONS: Y-27632 suppressed ureteric contractions in the rabbits with UUO. Western blot analysis also confirmed greater expression levels of ROCK-1 and ROCK-2 in the ureters of UUO rabbits. It is important to elucidate by which mechanisms the Rho-kinase pathway affects ureteric function after obstruction.