[The protective effect of reduced glutathione and oxygen persufflation on rat steatotic grafts following transplantation].
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Animals↗
Biomedical subjects
Yan Xiong
Publications and source records attributed to Yan Xiong.
[Isolation, cultivation and identification of liver sinusoidal endothelial cells in rats].
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Animals↗
A flow-injection ultrafiltration sampling chemiluminescence system for on-line determination of drug-protein interaction.
A flow-injection ultrafiltration sampling chemiluminescence system for on-line determination of cimetidine-bovine serum albumin (BSA) interaction is proposed in this paper. Cimetidine can be oxidized by N-bromosuccinimide (NBS) and sensitized by fluorescein to produce high chemiluminescence emission in basic media. The concentration of cimetidine is linear with the CL intensity in the range 3 x 10(-7) - 1 x 10(-4) mol L(-1) with a detection limit of 1 x 10(-7) mol L(-1) (3 sigma). The drug and protein were mixed in different molar ratios in 0.067 mol L(-1) phosphate buffer, pH 7.4, and incubated at 37 degrees C in a water bath. The ultrafiltration probe was utilized to sample the mixed solution at a flow rate of 5 micro L min(-1). The data obtained by the proposed ultrafiltration flow-injection chemiluminescence method was analyzed with Scrathard analysis and a Klotz plot. The estimated association constant ( K) and the number of the binding site ( n) on one molecule of BSA by Scrathard analysis and Klotz plot were 3.15 x 10(4) L mol(-1) and 0.95, 3.25 x 10(4) L mol(-1) and 0.92, respectively. The proposed system proved that flow-injection chemiluminescence analysis coupled with on-line ultrafiltration sampling is a simple and reliable technique for the study of drug-protein interaction.
Binding Sites↗
Elevated levels of the serum endogenous inhibitor of nitric oxide synthase and metabolic control in rats with streptozotocin-induced diabetes.
This study was designed to determine the relationship between elevated levels of the endogenous inhibitor of nitric oxide synthase, asymmetric dimethylarginine (ADMA), and metabolic control in rats with streptozotocin-induced diabetes. Serum levels of ADMA were measured by high-performance liquid chromatography at 8 weeks after diabetes was induced. Endothelium-dependent relaxation to acetylcholine was tested in aortic rings from nondiabetic age-matched control, untreated diabetic, and insulin-treated diabetic rats to evaluate endothelial function. Serum concentrations of glucose, glycosylated serum protein, and malondialdehyde were examined to estimate metabolic control. Serum levels of ADMA increased dramatically in untreated diabetic rats compared with control rats. This elevation in ADMA levels was accompanied by impairment of the endothelium-dependent relaxation response to acetylcholine in aortic rings. Long-term insulin treatment not only prevented the elevation of serum ADMA levels, but also improved the impairment of endothelium-dependent relaxation in diabetic rats. Serum levels of glucose, glycosylated serum protein, and malondialdehyde were significantly increased in parallel with the elevation of ADMA in untreated diabetic rats compared with control rats. These parameters were normalized after diabetic rats received insulin treatment for 8 weeks. These results provide the first evidence that an elevation in the concentration of ADMA in rats with streptozotocin-induced diabetes is closely related to metabolic control of the disease.
Animals↗
Captopril restores endothelium-dependent relaxation of rat aortic rings after exposure to homocysteine.
This study was designed to investigate the effects of captopril, an angiotensin-converting enzyme inhibitor, on inhibition of endothelium-dependent relaxation induced by homocysteine in isolated rat aorta. Isometric tension recordings were used to assess inhibitory effects of homocysteine and protective effects of captopril on endothelium-dependent relaxation of aortic rings. Exposure of aortic rings to homocysteine (0.3 approximately 3 mmol/L) for 30 min induced a significant concentration-dependent inhibition of endothelium-dependent relaxation response to acetylcholine (ACh), but did not affect endothelium-independent relaxation response to sodium nitroprusside. Pre-incubation of aortic rings with captopril (3 approximately 30 micromol/L) for 15 min and co-incubation of aortic rings with homocysteine (1 mmol/L) for another 30 min attenuated the inhibition of homocysteine in a dose-dependent manner. Moreover, superoxide dismutase (SOD, 200 U/mL), a scavenger of superoxide anions, reduced homocysteine-induced inhibition. L-Arginine (3 mmol/L), a precursor of nitric oxide (NO), also attenuated the impairment of vasorelaxation induced by homocysteine. However, in the combined presence of SOD and L-arginine, the inhibitory effect of homocysteine was reversed, which was very similar to the effect of 30 micromol/L captopril. These results suggest that captopril can prevent the inhibition of endothelium-dependent relaxation induced by homocysteine in isolated rat aorta, which may be related to scavenging oxygen free radicals and enhancing NO production.
Acetylcholine↗
[Hippocampal formations, amygdala and anterior temporal lobes: normative volumetric measurements from MR imaging in normal adults of China].
OBJECTIVE: To define the normal range of volumetric values of hippocampal formations (HPF), amygdala (AM) and anterior temporal lobes (ATL). METHODS: One hundred and two Chinese normal adults underwent MRI scan on oblique coronal section. Volumes of the anterior temporal lobes, hippocampal formations and amygdala were obtained on T1WI. The mean values and the range of 95% normal values were obtained by statistical data processing and analysis. RESULTS: The mean values of standardized volumes of anterior temporal lobes in the subjects aged 20 yr.-, 40 yr.- and > or = 60 yr. were: 59.07 +/- 2.02 cm3, 55.55 +/- 2.23 cm3, 52.88 +/- 2.07 cm3 (Right); 57.25 +/- 2.15 cm3, 53.23 +/- 1.72 cm3, 51.63 +/- 2.18 cm3 (Left); and of amygdala in those aged 20 yr.-, 40 yr.- and > or = 60 yr. were: 1.54 +/- 0.09 cm3, 1.38 +/- 0.08 cm3, 1.29 +/- 0.09 cm3 (R); 1.37 +/- 0.09 cm3, 1.29 +/- 0.08 cm3, 1.23 +/- 0.09 cm3(L). The 95% normal values of HPF in the subjects aged 20 yr.- ranged from 2.52 to 3.11 cm3(R), and from 2.40 to 2.98 cm3(L); in those aged > or = 60 yr. ranged from 2.33 to 2.65 cm3 (R) and from 1.98 to 2.64 cm3(L). There was no significant difference in the volumes of hippocampal formations between two groups under 60 yr.. And a decrease of the volumes of hippocampal formations could been seen in the > or = 60 yr. group. No significant difference in the volumes of hippocampal formations, amygdala and anterior temporal lobes was seen in the sex groups and handedness groups. CONCLUSION: The data on standardized volumes of HPF, AM, ATL in this study can serve as a foundation on which to provide normal index and useful guidelines for reference in early diagnosis and treatment of Alzheimer's disease and temporal lobe epilepsy.
Age Factors↗