Effect of a novel phosphodiesterase 5 inhibitor, CPD1, on renal interstitial fibrosis after unilateral renal ischemia-reperfusion injury / 生理学报

This study was designed to evaluate the protective effect of CPD1, a novel phosphodiesterase 5 inhibitor, on renal interstitial fibrosis after unilateral renal ischemia-reperfusion injury (UIRI). Male BALB/c mice were subjected to UIRI, and treated with CPD1 once daily (i.g, 5 mg/kg). Contralateral nephrectomy was performed on day 10 after UIRI, and the UIRI kidneys were harvested on day 11. Hematoxylin-eosin (HE), Masson trichrome and Sirius Red staining methods were used to observe the renal tissue structural lesions and fibrosis. Immunohistochemical staining and Western blot were used to detect the expression of proteins related to fibrosis. HE, Sirius Red and Masson trichrome staining showed that CPD1-treated UIRI mice had lower extent of tubular epithelial cell injury and deposition of extracellular matrix (ECM) in renal interstitium compared with those in the fibrotic mouse kidneys. The results from immunohistochemistry and Western blot assay indicated significantly decreased protein expressions of type I collagen, fibronectin, plasminogen activator inhibitor-1 (PAI-1) and α-smooth muscle actin (α-SMA) after CPD1 treatment. In addition, CPD1 dose-dependently inhibited the expression of ECM-related proteins induced by transforming growth factor β1 (TGF-β1) in normal rat kidney interstitial fibroblasts (NRK-49F) and human renal tubular epithelial cell line (HK-2). In summary, the novel PDE inhibitor, CPD1, displays strong protective effects against UIRI and fibrosis by suppressing TGF-β signaling pathway and regulating the balance between ECM synthesis and degradation through PAI-1.

Alteration of tetraethylammonium-sensitive potassium current in pulmonary artery smooth muscle cells of pulmonary hypertension rats / 中国药理学通报

Aim To investigate the alteration of volt-age-depending potassium channel(KV) current in pul-monary arterial smooth muscle cells(PASMCs) of pul-monary hypertension (PH) rats, and the effect of tet-raethylammonium (TEA,a blocker of KV) on potassi-um channel current in different PH models. Methods The whole-cell patch clamp techniques were applied to record the KVcurrents from PASMCs cultured with Ham's F-12 (1% FBS). Furthermore, the effects of TEA on the KVcurrents were examined in different PH models. Results The whole-cell KVcurrents were ob-viously inhibited in PASMCs of chronic hypoxia (CH)and monocrotaline (MCT)-treated rats. TEA signifi-cantly decreased the whole-cell KVcurrents in PASMCs of control and PH rats,and the inhibitory effect of TEA was dramatically reduced in PH group. Conclusions The degree of the voltage-dependent potassium chan-nels opening is significantly inhibited in PASMCs of CH and MCT-treated rats,accordingly,the TEA-sen-sitive KVcurrents obviously decrease.

Comparison of agonists-induced contraction between main and the third-order branches of pulmonary arteries in rats / 生理学报

This study was designed to observe the differences between main pulmonary arteries and the third-order branches of pulmonary arteries in the contractile response to phenylephrine (Phen), endothelin-1 (ET-1) and potassium chloride (KCl). The vascular tension changes of main and the third-order branches of pulmonary arteries induced by KCl, ET-1 and Phen were recorded by traditional vascular tone detection methods and microvascular ring technique, respectively. The results showed that Phen could cause a significant contraction in main pulmonary arteries, but did not induce apparent contraction in the third-order branches of pulmonary arteries. Compared with main pulmonary arteries, ET-1 contracted the third-order branches of pulmonary arteries with reduced maximal response value and PDvalue. In comparison with the main pulmonary arteries, contraction caused by KCl was enhanced in the third-order branches of pulmonary arteries. The results suggest that the vascular reactivity of main and the third-order branches of pulmonary arteries is different and it is important to study the vascular function of small branches of pulmonary arteries. This study could provide an important experimental basis for the further study on vascular function of small branches of pulmonary arteries and the functional changes in pulmonary hypertension.

Comparison of the synchronous changes of vascular tension and intracellular Casignal in third-order branches of mesenteric arteries under the different objective amplification of confocal microscope / 生理学报

This study was aimed to establish an optimized method to observe the synchronous changes of vascular tension and intracellular Casignal in the third-order branches of mesenteric arteries (sMA, diameter: 100-300 μm). The vascular tension and intracellular Casignal changes in response to potassium chloride (KCl), endothelin-1 (ET-1) and Gdwere detected using confocal wire myograph system and confocal laser scanning microscopy imaging technique, respectively. The experimental results were analyzed to explore the optimal experimental conditions. The results showed that KCl caused contraction in sMA significantly, and the intracellular Calevel of vascular smooth muscle cells (VSMCs) was also increased under 20× and 40× objective lens. Compared with those under the 40× objective lens, the Casignal change was larger and the fluorescence value was more stable under the 20× objective lens, whereas the Casignal change was not obvious under the 10× objective lens. ET-1 (1-10 nmol/L) caused concentration dependent contraction in sMA significantly, and the intracellular Casignal of VSMCs was also enhanced in a concentration dependent manner. Additionally, Gdsignificantly reduced the contraction of sMA and the intracellular Casignal of VSMCs caused by ET-1. The results suggest that the intracellular Casignal of VSMCs changes with vascular contraction or relaxation caused by the agonists or antagonists of Cachannels. We successfully recorded both changes synchronously using confocal wire myograph system and confocal laser scanning microscopy imaging technique at the same time. Based on the analysis of the experimental results, we concluded that 20× objective lens provides the best experimental condition. Compared to combination of vascular tone detection method and real-time cellular fluorescence imaging technique, the present synchronous method is convenient and helpful to reduce experimental error.