AMP-activated protein kinase activation and NADPH oxidase inhibition by inorganic nitrate and nitrite prevent liver steatosis.

Advanced age and unhealthy dietary habits contribute to the increasing incidence of obesity and type 2 diabetes. These metabolic disorders, which are often accompanied by oxidative stress and compromised nitric oxide (NO) signaling, increase the risk of adverse cardiovascular complications and development of fatty liver disease. Here, we investigated the therapeutic effects of dietary nitrate, which is found in high levels in green leafy vegetables, on liver steatosis associated with metabolic syndrome. Dietary nitrate fuels a nitrate-nitrite-NO signaling pathway, which prevented many features of metabolic syndrome and liver steatosis that developed in mice fed a high-fat diet, with or without combination with an inhibitor of NOS (l-NAME). These favorable effects of nitrate were absent in germ-free mice, demonstrating the central importance of host microbiota in bioactivation of nitrate. In a human liver cell line (HepG2) and in a validated hepatic 3D model with primary human hepatocyte spheroids, nitrite treatment reduced the degree of metabolically induced steatosis (i.e., high glucose, insulin, and free fatty acids), as well as drug-induced steatosis (i.e., amiodarone). Mechanistically, the salutary metabolic effects of nitrate and nitrite can be ascribed to nitrite-derived formation of NO species and activation of soluble guanylyl cyclase, where xanthine oxidoreductase is proposed to mediate the reduction of nitrite. Boosting this nitrate-nitrite-NO pathway results in attenuation of NADPH oxidase-derived oxidative stress and stimulation of AMP-activated protein kinase and downstream signaling pathways regulating lipogenesis, fatty acid oxidation, and glucose homeostasis. These findings may have implications for novel nutrition-based preventive and therapeutic strategies against liver steatosis associated with metabolic dysfunction.

Effect of clemastine fumarate on lung ischemia-reperfusion injury in rabbits / 中华麻醉学杂志

Objective To investigate the effect of clemastine fumarate on lung ischemia-reperfusion (I/R) injury in rabbits.Methods Fifty New Zealand white rabbits of both sexes,weighing 2.0-3.0 kg,were divided into 3 groups using a random number table:sham operation group (Sham group,n =10),I/R group (n =20) and clemastine fumarate group (Cle group,n =20).The model of lung I/R was established by clamping the left hilum of lung and decreasing the tidal volume followed by restoration of perfusion and ventilation 1 h later in I/R and Cle groups.At 3 h of ventilation in group Sham and 2 and 4 h of reperfusion in I/R and Cle groups,blood samples were collected for determination of serum tumor necrosis factoralpha (TNF-α) and interleukin-8 (IL-8) concentrations by enzyme-linked immunosorbent assay.The left lung was lavaged,and the broncho-alveolar lavage fluid (BALF) was colleted for determination of white blood cell count.Lung specimens were obtained for microscopic examination of the ultrastructure of lung tissues and for determination of wet/dry weight ratio (W/D ratio),expression of IL-1β and IL-6 mRNA (by real-time polymerase chain reaction) and cell apoptosis (by TUNEL).The apoptosis rate was calculated.Results Compared with Sham group,the W/D ratio,white blood cell count in BALF,serum concentrations of TNF-α and IL-8 and apoptosis rate were significantly increased,and the expression of IL-1β and IL-6 mRNA was up-regulated in I/R and Cle groups (P＜0.05 or 0.01).Compared with I/R group,the W/D ratio,white blood cell count in BALF,serum concentrations of TNF-α and IL-8 and apoptosis rate were significantly decreased,and the expression of IL-1β and IL-6 mRNA was down-regulated in Cle group (P＜0.05 or 0.01).The pathological changes of lung tissues were significantly attenuated in Cle group than in I/R group.Conclusion Clemastine fumarate can attenuate lung I/R injury in rabbits.

Effects of Clemastine Fumarate on Expression of Toll Like Receptor 4 in Lung Ischemia-Reperfusion / 实用医学杂志

Objective To explore the expression change of Toll Like Receptor 4 (TLR4) in lung ischemia-reperfusion injury in rabbits and the influence of clemastine fumarate on it. Methods Fifty rabbits were divided into five groups randomly (n=10): Sham (N+S), reperfusion for 2 hours (N+I1/R2), reperfusion for 4 hours (N+I1/R4), clemastine fumarate + reperfusion for 2 hours (F+I1/R2) and clemastine fumarate+reperfusion for 4 hours (F+I1/R4). The ischemia time in each group was 1 hour and normal saline was given respectively in groups of N+S , N+I1/R2 and N+I1/R4. Western blotting , RT-PCR and immunofluorescence were used to detect the expression of TLR4 in lung tissue , and the changes of ultrastructure in ischemia-reperfusion lung tissue were observed by electron microscope. Result The expression of TLR4 was elevated obviously in ischemia-reperfusion lung tissue (P<0.05), and there was positive correlation between the increased TLR4 level and reperfusion time (P<0.05), the swelled and thick-ridge mitochondria were observed in type II alveolar epithelial cells after LIRI (P<0.05); but clemastine fumarate inhibited the expression of TLR4 in lung tissue significantly caused by LIRI (P<0.05). And the mitochondria injury was reduced in the groups of clemastine fumarate. Conclusion TLR4 expression is elevated in lung tissue after LIRI; clemastine fumarate inhibits the expression of TLR4 caused by LIRI and protects the lung tissue from LIRI in rabbits.

Effects of metformin on endocrine function of the pitutary-gonad axis in rats / 中国药理学通报

Aim To study the effects of Metformin (MF) on endocrine function of pituitary-gonad axis in rats. Methods The serum hormone concentration was measured with radioimmunoassay (RIA) and the morphology of gonad endocrine cells was observed with electron microscope. Results MF(135 mg?kg-1?d-1,ig,14 d)decreased serum T concentration in male rats and serum LH concentrations in female rats significantly(P

Isolation of Calcium-Tolerant Cardiomyocytes from Rats / 中国药房

OBJECTIVE:To investigate the method for rapid and effective isolating of calcium-tolerant cardiomyocytes(CTC) from rats. METHODS: CTC were obtained by retrograde perfusion using modified Langendorff heart perfusion apparatus. After incubation of cardiomyocytes in KB solution, the ion currents were recorded with patch-clamp technique in whole-cell mode. RESULTS: Of the whole isolated cells, 70% were survival. Of which, 80% were CTC. A typical outward potassium current was recorded. CONCLUSIONS: A large number of CTC with normal electrophysiological characteristics can be obtained by mastering the digestion time based on variation of perfusion pressure and keeping all the factors in cell isolation under control.

Effects of Metformin on Serum Sex Hormone and Leptin in Ovariectormized Female Rats / 中国药房

OBJECTIVE:To study the effects of metformin (MF)on serum sex hormone and leptin contents in ovariectormized female rats. METHODS: 40 SD rats were randomly divided into four groups: control group(normal saline 5 mL? kg-1?d-1,NS group),OVX group(normal saline 5 mL?kg-1?d-1),OVX+low and high dosage MF group(135,270 mg? kg-1?d-1,MFlow and MFhigh group),all group were ig drugs for 30 days on end.The serum sex hormone indexes including E2,P,LH,LSH and leptin content were measured with RIA. RESULTS:Compared with NS group,the serum E2 and P content were significantly lower(P0.05). CONCLUSIONS: MF can significantly improve sex hormone secretion and lower serum content of LEP in OVX rats.

Effects of metformin on the pitutary-gonad axis calmodulin mRNA expression in rats / 中国药理学通报

Aim To study effects of metfomin(MF) on calmodulin(CaM) mRNA exprssion of the pitutary-gonad axis in rats.Methods The CaM mRNA expression of the pitutary-gonad axis in rats was measured with the real time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) technique. Results MF (270 mg?kg-1?d-1,ig,21 d) significantly inhibited the CaM mRNA expression in testes (P