Objective To establish a stable method for acute isolation of atrial myocytes in diabetic rats,so as to provide materials for electrophysio?logical study of diabetic rats. Methods Streptozotocin(STZ)was used to establish type I diabetic model. Atrial myocytes were isolated with modi?fied perfusion buffer by Langendorff perfusion. The atrial myocytes were morphologically observed with optical microscope and identified by morphol?ogy and immunofluorescence staining. The action potential was recorded by patch clamp technique. Results STZ can establish a stable type I dia?betic model. The modified perfusion method can yield calcium tolerant and spindle shaped atrial myocytes. Immunofluorescence indicated that atrial myocytes were positive for Kv1.5 which was expressed in atrial myocytes. The atrial myocytes obtained by this method were able to generate action po?tentials. Conclusion The modified perfusion method is suitable for acute isolation of atrial myocytes in rats with diabetes mellitus,which may help to study the electrophysiology of diabetic heart.

Objective:To observe the effect of Zeyin pill on cell apoptosis in mice with non-alcoholic fatty liver disease (NAFLD) and its possible mechanism.Methods:A total of 36 mice were fed with high-fat diet for 12 weeks to establish a NAFLD model, and were randomly divided into NAFLD group, experimental group A, and experimental group B, with 12 mice in each group. Another 10 mice were fed with regular feed and included in the control group. Experimental groups A and B were orally administered with concentrated Zeyin pill at doses of 2.25 and 4.5 g/kg, respectively, once a day. The control group and the NAFLD group were given equal volume saline by gavage, and were intervened continuously for 4 weeks. Serum fasting blood glucose (FBG), insulin, dipeptidyl peptidase-4 (DPP4) enzyme activity, and oral glucose tolerance test (OGTT) results of four groups were compared; Four groups were compared in terms of liver index, total cholesterol (TC), and triglyceride (TG) content in liver tissue; The apoptosis rate of four groups of liver tissue cells was detected by TdT-mediated dUTP nick end labeling (Tunel) staining method; Oil red O staining was used to observe lipid deposition in four groups of liver tissues; Protein immunoblotting was used to detect the protein expression of DPP4, nuclear transcription factor kappa B (NF-κB) p65, p-NF-κB p65, and caspase-3 in liver tissue.Results:The blood glucose levels in the NAFLD group were higher than those in the control group at 30, 60, and 120 minutes after FBG and OGTT (all P<0.05); The blood glucose levels in groups A and B after FBG and OGTT were lower than those in the NAFLD group at 30, 60, and 120 minutes (all P<0.05); The blood glucose levels in group B were lower than those in group A at 30, 60, and 120 minutes after FBG and OGTT (all P<0.05). The insulin and DPP4 enzyme activities, liver index, liver tissue TC and TG content, and liver cell apoptosis rate in the NAFLD group were all higher than those in the control group (all P<0.05); The insulin and DPP4 enzyme activities, liver index, liver tissue TC and TG content, and liver cell apoptosis rate in groups A and B were all lower than those in the NAFLD group (all P<0.05); The insulin and DPP4 enzyme activities, liver index, liver tissue TC and TG content, and liver cell apoptosis rate in experimental group B were all lower than those in experimental group A (all P<0.05). The Oil Red O staining results showed that there was no significant lipid deposition in the control group, while the NAFLD group exhibited diffuse distribution of orange red lipid droplets and large vesicular steatosis. The number of orange red lipid droplets in the liver tissue of experimental groups A and B was less than that of the NAFLD group, and the number of orange red lipid droplets in experimental group B was less than that of experimental group A. The results of protein immunoblotting showed that the expression levels of DPP4, Caspase-3 proteins and p-NF-κB p65/NF-κB p65 in liver tissue of NAFLD group were higher than those of the control group (all P<0.05); The expression levels of DPP4 and Caspase-3 proteins, as well as p-NF-κB p65/NF-κB p65, in the liver tissues of groups A and B were lower than those in the NAFLD group (all P<0.05); The expression levels of DPP4 and Caspase-3 proteins, as well as p-NF-κB p65/NF-κB p65, in the liver tissue of experimental group B were lower than those in experimental group A (all P<0.05). Conclusions:Zeyin Pill can lower blood glucose levels, reduce liver cell apoptosis and lipid deposition in NAFLD mice, possibly by inhibiting the DPP4/NF-κB signaling pathway.

ObjectiveBased on ultra performance liquid chromatography-quadrupole-time-of-flight mass spectrometry（UPLC-Q-TOF-MS^E） technique， we identified qualitatively the metabolites of aristolochic acid（AAs） in rat in order to analyze the metabolic differences between water extract of Aristolochiae fructus（AFE） and Aristolochic acid Ⅰ（AAⅠ）. MethodSD rats were selected and administered AFE（110 g·kg^-1·d^-1） or AAⅠ（5 mg·kg^-1·d^-1） by oral for 5 days， respectively. Serum， urine and feces were collected after administration. Through sample pretreatment， ACQUITY UPLC BEH C₁₈ column（2.1 mm×100 mm， 1.7 μm） was used with the mobile phase of 0.01% formic acid methanol（A）-0.01% formic acid water（B， containing 5 mmol·L^-1 ammonium acetate） for gradient elution（0-1 min， 10%B； 1-7 min， 10%-75%B； 7-7.2 min， 75%-95%B； 7.2-10.2 min， 95%B； 10.2-10.3 min， 95%-10%B； 10.3-12 min， 10%B） at a flow rate of 0.3 mL·min^-1. Positive ion mode of electrospray ionization（ESI⁺） was performed in the scanning range of m/z 100-1 200. In combination with UNIFI 1.9.4.053 system， the Pathway-MS^E was used to qualitatively analyze and identify the AAs prototype and related metabolites in biological samples（serum， urine and feces）， and to compare the similarities and differences of metabolites in rats in the subacute toxicity test between AFE group and AAⅠ group. ResultCompared with AAⅠ group， 6， 10， 13 common metabolites and 14， 20， 30 unique metabolites were identified in biological samples（serum， urine and feces） of AFE group， respectively. Moreover， the main AAs components always followed the metabolic processes of demethylation， nitrate reduction and conjugation. Compared with common metabolites in AAⅠ group， prototype components of AAⅠ in serum and most metabolic derivatives of AAⅠ［AAⅠa， aristolochic lactam Ⅰ（ALⅠ）a， 7-OHALⅠ and its conjugated derivatives］ in biological samples were significantly increased in AFE group（P<0.05， P<0.01）， except that the metabolic amount of ALⅠ in feces of AFE group was remarkably lowed than that of AAⅠ group（P<0.01）. In addition， a variety of special ALⅠ efflux derivatives were also identified in the urine and feces of the AFE group. ConclusionAlthough major AAs components in AFE all show similar metabolic rules as AAⅠ components in vivo， the coexistence of multiple AAs components in Aristolochiae Fructus may affect the metabolism of AAⅠ， and achieve the attenuating effect by increasing the metabolic effection of AAⅠ and ALⅠ.