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Previously we have described the properties of store-operated channel currents (SOCs) in freshly dispersed rabbit portal vein smooth muscle cells. In addition to Ca2+ store depletion these SOCs could also be activated by α-adrenoceptor stimulation and diacylglycerol (DAG) via a protein kinase C (PKC)-dependent mechanism. In the present study we have investigated the effect of β-adrenoceptor stimulation on SOCs in rabbit portal vein myocytes. With whole-cell recording the selective β-adrenoceptor agonist isoprenaline reduced the current evoked by cyclopiazonic acid (CPA, sarcoplasmic/endoplasmic reticulum ATPase inhibitor) by over 85%. With cell-attached patch recording, bath application of isoprenaline produced a pronounced inhibition of SOC activity evoked by either CPA or the acetoxymethyl ester form of BAPTA (BAPTA-AM). SOC activity evoked by CPA, the DAG analogue, 1-oleoyl-acetyl- sn -glycerol (OAG) or the phorbol ester, phorbol-12,13-dibutyrate (PDBu) was also markedly inhibited by the adenylate cyclase activator, forskolin, and the cell-permeable non-hydrolysable analogue of cyclic adenosine monophosphate (cAMP), 8-Br-cAMP. With inside-out patches, bath application of PDBu evoked channel currents with similar properties to SOCs which were inhibited by over 90% by a catalytic subunit of protein kinase A (PKA) and by 8-Br-cAMP. Moreover bath application of PKA inhibitors, H-89, KT5720 and an inhibitory peptide to quiescent cell-attached or inside-out patches, activated channel currents with similar properties to SOCs. These data suggest that in rabbit portal vein myocytes, stimulation of β-adrenoceptors inhibits SOC activity via a cAMP-dependent protein kinase signal transduction cascade. In addition it is concluded that constitutive PKA activity has a profound inhibitory effect on SOC activity in this vascular preparation. 相似文献
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Steegmans PH Bosman A Chin-A-Lien RA Schop WA van der Meijden WI 《Nederlands tijdschrift voor geneeskunde》1999,143(46):2315-2318
OBJECTIVE: To detect risk groups in an increase of early (infectious) syphilis. DESIGN: Retrospective study of patient records. METHOD: Data from visitors with an early syphilis were collected from their respective medical records in the outpatient clinic for sexually transmitted diseases (STD) of the Academic Hospital Rotterdam-Dijkzigt, the Netherlands, over the years 1993-1997. In particular, data on risk behaviour and risk groups were collected. To obtain an indication of the (possible) causes of the increase in the number of visitors with early syphilis, (shifts in) characteristics of this population over the years were compared. RESULTS: 195 patients with early syphilis had visited the outpatient clinic, 130 males and 65 females, mean ages ranging from 30.9 (1993) to 38.1 years (1997). Most infected persons (68%) came to the outpatient clinic because of symptoms. The number of women who came to the outpatient clinic through partner notification increased considerably, from an average of 5% in 1993-1995 to 36% in 1996. Over the years a relative increase of (drug addicted) prostitutes and their clients was observed (1993-1995: 39%; 1996: 56%). CONCLUSION: The cause of the increase, or failure to decrease, of the number of syphilis-infected visitors in the STD outpatient clinic of the Academic Hospital Rotterdam-Dijkzigt should probably be sought among (drug addicted) prostitutes and their visitors. 相似文献
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目的:观察应用凌晨3:00皮下注射短效胰岛素治疗2型糖尿病黎明现象的疗效。方法:对40例有黎明现象的2型糖尿病患者,使用短效胰岛素凌晨3:00注射4~6U。抽取肘静脉血测定空腹血糖(FPG)及早餐后2h血糖(2hPG),免疫比浊法测定糖化血红蛋白(HbA1c),比较治疗前后上述指标变化。结果:本组患者FPG从治疗前(9.5±1.6)mmol/L下降至(6.0±0.4)mmol/L,治疗2个月后仍保持为(5.6±0.4)mmol/L;2hPG从治疗前(13.8±0.8)mmol/L下降至(7.4±0.4)mmol/L,在治疗2个月后保持为(7.9±0.3)mmol/L;FPG和2hPG与治疗前比较,均具有显著性差异(P<0.01)。治疗2个月后,HbA1c从治疗前(8.3±0.6)%下降至(6.5±0.3)%,与治疗前比较,有显著性差异(P<0.01)。结论:短效胰岛素强化治疗黎明现象具有快速稳定的降血糖和降糖化血红蛋白作用。 相似文献
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目的探讨硫酸锌对高脂喂养载脂蛋白E(ApoE)基因敲除小鼠血脂和氧化低密度脂蛋白(oxLDL)水平,及主动脉中基质金属蛋白酶9(MMP-9)和细胞分化抗原40(CD40)mRNA表达的影响。方法 AopE基因敲除小鼠连续14周喂饲高脂饲料,同时分别给予小鼠浓度为2.5、25 mmol/L硫酸锌水溶液作为低剂量组和高剂量组。测定小鼠血脂和oxLDL水平,并测定主动脉中MMP-9和CD40 mRNA表达水平。结果低剂量组和高剂量组小鼠血清中甘油三酯和oxLDL水平明显低于动脉粥样硬化(AS)模型组(P〈0.01)。低剂量组和高剂量组小鼠主动脉MMP-9 mRNA和CD40 mRNA水平与AS模型组没有差异。结论补充硫酸锌降低了AS模型动物的甘油三酯和oxLDL水平,具有潜在的抗AS作用,但对主动脉MMP-9和CD40 mRNA表达无影响。 相似文献