Research progression of deacetylase (SIRT1) / 中国医学科学院学报

The silent information regulator protein 2 (Sir2) and its homologues play an important role in the regulation of cellular physiological processes such as survival, apoptosis, and aging. SIRT1, the mammalian Sir 2 homologue, has been shown to deacetylate a wide range of non-histone substrates and histone substrates. It has been constantly reported that SIRT1 may be associated with the occurrence of metabolic syndrome, genomic homeostasis, tumors, and neurodegenerative diseases. Calorie restriction may mitigate many major diseases in rodent models by SIRT1-mediated deacetylase activity and prolong the life expectancies in these animals. Therefore, SIRT1 may be emphasized as a new therapy target for many different diseases.

Effect of melatonin on blood pressure and aortic relaxation and contraction activity from hypertensive rats / 中国药理学通报

AIM: To observe the hypotensive effect of melatonin (MT) on two-kidney one-clip renal hypertensive (2K1C) rats and to explore its aortic mechanism. METHODS: 2K1C rats were obtained by narrowing the left kidney artery; systolic blood pressure was measured by use of tail-cuff method; vascular actions of MT were measured using isolated blood vessel method. RESULTS: MT reduced blood pressure of 2K1C rat significantly [(C23.45 ± 2.40) kPa versus (19.81 ± 2.78) kPa, P < 0.05]; MT (10-4 mol • L-1), restored vasodilation to acetyl-choline partially (P < 0.01) and attenuated vasoconstriction to norepinephrine (P < 0.05) in isolated aortic rings from 2K1C rats. MT(10-5 ∼ 10-3 mol • L-1) also inhibited vasoconstriction of aortic rings to KCl (70 mmol · L-1) and this action had no significant difference in sham and 2K1C rats. CONCLUSION: Vascular activities of MT is one of the factors involved in its hypotensive effect. MT restores the endothelial dysfunction and the balance of oxidative condition in smooth muscle cell by its free radical scavenging and antioxidant properties.