ABSTRACT
Objective To study the mechanism of metoprolol preventing pressure overload induced myocardial hypertrophy through inhibiting calcineurin (CaN) and CalpainⅠsignaling pathway in rat model of coarctation of abdominal aorta. Methods Thirty SD rats were used for hypertension rat model induced by coarctation of suprarenal abdominal aorta. Model rats were divided into three groups, sham operation group (n=10), abdominal aortic coarctation group (n=9) and metoprolol group (n=9). The changes of blood pressure [systolic blood pressure (SBP) and diastolic blood pressure (DBP)] and myocardial hypertrophy [the ratio of left ventricular mass/ body mass (LVW/BW)] were measured. RT-PCR was used to detect the expression of CaN mRNA, and Western blot assay was used to detect expressions of CaN and CalpainⅠproteins. The activity of CaN enzyme was detected and compared between three groups. Results Compared with the sham-operated sham operation group, values of SBP, DBP, LVW/BW, protein expressions and activities of CaN mRNA, CaN and CalpainⅠwere significantly increased in operation group (P<0.05). There were no significant differences in SBP and DBP between metoprolol-treated group and the operation group (P>0.05). Furthermore, values of SBP and DBP were significantly higher in metoprolol-treated group than those of sham group (P<0.05). Compared with operation group, values of LVW/BW, the protein expression and activity of CaN mRNA and Calpain Ⅰwere significantly decreased in metoprolol group (P<0.05), which were no significant differences compared with sham group. Conclusion Metoprolol prevents myocardial hypertrophy in abdominal aorta coarctative rats, through inhibiting CalpainⅠand CaN signaling pathways.
ABSTRACT
Objective To investigate the effect of donepezil hydrochloride on the expression of Calpain Ⅰ-Cdk5/p25 pathway in the hippocampal CA1 area by cerebral ischemia and reperfusion in mice.Methods Mice were divided into model group,sham-operated group and donepezil-treated group.The expression of Calpain Ⅰ in hippocampal CA1 area was measured by immunohistochemistry staining respectively at 4,6 and 8 weeks post cerebral ischemia and reperfusion.Western blot was used to evaluate Cdk5 and p25 protein expression.Results The abilities of learning and memory performance was damaged significantly at 4,6 and 8 weeks after surgery compared to sham-operated group (P＜ 0.05).The expression of Calpain Ⅰ of model group were (0.098 ± 0.009),(0.129 ±0.01),(0.116 ± 0.01),which were higher than that of sham-operated group (0.03 ± 0.003),(0.031 ± 0.003),(0.029 ±0.003) and there was significant difference (P ＜ 0.05).The expression of Cdk5 in model group was (0.54 ± 0.05),(0.73 ± 0.07),(0.7 ± 0.06),which were higher than that of sham-operated group (0.23 ±0.02),(0.31 ± 0.02),(0.33 ± 0.02) and there was significant difference (P ＜ 0.05).The expression of p25 in model group was (0.44 ± 0.04),(0.51 ± 0.04),(0.55 ± 0.06),which were higher than that of sham-operated group(0.19 ± 0.02),(0.24 ± 0.02),(0.2 ± 0.02) and there was significant difference (P ＜ 0.05).The expression of Calpain Ⅰ of donepezil-treated group was (0.041 ± 0.004),(0.054 ± 0.004),(0.046 ± 0.003),which were lower than that of model group.The expression of Cdk5 was (0.28 ± 0.02),(0.33 ± 0.03),(0.38 ± 0.02),and expression of p25 was (0.26 ± 0.02),(0.25 ± 0.03),(0.21 ± 0.02),which were lower than that of model group respectively(P ＜ 0.05).Conclusion Donepezil hydrochloride probably improve the learning and memory abilities by reducing the expression of Calpain Ⅰ and Cdk5/p25.