阴式子宫切除术中应用右旋美托咪啶联合低浓度罗哌卡因腹横肌膜神经阻滞的有效性及安全性

目的:探究阴式子宫切除术中应用右旋美托咪啶+低浓度罗哌卡因腹横肌膜神经阻滞的有效性及安全性。方法:选取本院接受阴式子宫切除术治疗妇女120例,按照数字表法随机分为低浓度组、高浓度组各60例,分别给予右旋美托咪啶0.5μg/kg+罗哌卡因0.15%、右旋美托咪啶0.5μg/kg+罗哌卡因1.5%进行麻醉处理,对比分析两组感觉及运动神经阻滞情况及生命体征变化情况。结果:低浓度组麻醉后HR、MAP、VAS评分与高浓度组相比未见差异(P0.05),感觉恢复时间(233.3±10.1min)和运动恢复至Bromage0级时间(210.7±10.3min)优于对照组(293.5±11.4min、265.5±11.7min)(均P0.05)。结论:阴式子宫切除术中应用右旋美托咪啶+低浓度罗哌卡因腹横肌膜神经阻滞的效果较好,安全性高。     

人参皂甙对犬心肌Na~+、K~+-ATP酶活力的影响

人参茎叶总皂甙(GNS)和人参根总皂甙(GRS)10、20和40mg/kg,显著抑制犬心肌细胞膜Na~+,K~+-ATP酶的活力;人参茎叶二醇组皂甙(PDS)和三醇组皂甙(PTS)5、10和20mg/kg,也显著抑制Na~+,K~+-ATP酶的活力。离体实验表明:GNS、GRS、PDS和PTS在0.01、0.10和1.00g/L,对犬心肌细胞膜Na~+,K~+-ATP酶的活力均具有抑制作用。提示人参的正性肌力作用可能与其对心肌Na~+,K~+-ATP酶的抑制有关。     

云南甘草总皂甙对氧自由基诱导羊心肌细胞膜Na~＋，K~＋－ATP酶活性降低的保护作用

云南甘草总皂甙对正常羊心肌细胞膜Ｎａ＋，Ｋ＋－ＡＴＰ酶活性无影响；但对氧自由基诱导羊心肌细胞膜Ｎａ＋，Ｋ＋－ＡＴＰ酶活性的降低有明显保护作用，随浓度增高，酶的活性逐渐升高。与对照组比较，总皂甙浓度为０．２ｍｇ·Ｌ－１时，酶的活性恢复２７．９％，浓度为０．８ｍｇ·Ｌ－１，酶的活性恢复４６．６％。     

Association of soluble guanylate cyclase with the sarcolemma of mammalian skeletal muscle fibers

Previous investigations have shown that NO-producing nitric oxide synthase (NOS)-1 and CO-generating heme oxygenase (HO-2) are associated with the sarcolemma of skeletal muscle fibers in many mammalian species. Despite numerous roles ascribed to NO and possibly also CO in skeletal muscle, a specific receptor for both gases has hitherto not been found in myofibers. Therefore, in the present work the appearance of the alpha1, beta1 and beta2 subunits of soluble guanylate cyclase (sGC), the most commonly known receptor for NO and potentially also CO, was analysed in mammalian skeletal muscles using immunoblotting and immunohistochemistry. Immunoblotting with an antibody against the beta1 subunit of sGC revealed a band of 70 kDa corresponding to the molecular weight of this protein. Immunohistochemistry with antibodies against the alpha1, beta1 and beta2 sGC subunits showed that the larger part of positivity was present in the sarcolemma region of skeletal muscle fibers and colocalized with NOS-1 mainly in type II myofibers and with HO-2 in type I and type II myofibers. For the first time, sarcolemmal association of sGC and its colocalization with NOS-1 generating the sGC-activator NO and with HO-2 producing the potential sGC upregulator CO have been demonstrated in the present study. These results enable a better understanding of the role of NO and CO in myofibers and suggest a so far unknown molecular mechanism for the interaction of sGC with the sarcolemma.     

低浓度毒毛旋花子苷原对离体豚鼠衰竭心脏的影响

目的　研究低浓度毒毛旋花子苷原 (strophanthidin ,Str)对离体衰竭心脏心功能及心肌细胞膜Na+,K+ ATP酶活性的影响。方法　Langendorff离体心脏灌流装置制备戊巴比妥钠心衰模型 ,八道生理记录仪测定不同浓度Str对心功能的影响 ,无机磷法测定各组心肌细胞膜Na+,K+ ATP酶活性。结果　Str 1× 10 -9～ 1× 10 -7mol·L-1均能不同程度地持续增加衰竭心脏的心率、左室收缩压及左室收缩的最大速率 ,但 1× 10 -7mol·L-1对Na+,K+ ATP酶活性无明显抑制 ,1× 10 -10 ～ 1× 10 -8mol·L-1则可升高Na+,K+ ATP酶的活性 (P <0 0 5或P <0 0 1)。 1× 10 -6 ～ 1× 10 -4 mol·L-1可使心功能指标先升高、后降低 ,且伴有心脏收缩不规则和心律失常 ,也可剂量依赖性地抑制Na+,K+ ATP酶活性 (P <0 0 1)。结论　高浓度Str的正性肌力及伴有的心脏毒性作用是通过抑制Na+,K+ ATP酶实现的 ;而低浓度的正性肌力作用则和Na+,K+ ATP酶抑制无关     

Differential actions of calcium antagonists on calcium binding to cardiac sarcolemma

The action of four calcium antagonistic drugs, including verapamil, bepridil, nifedipine, and diltiazem, on calcium binding to cardiac sarcolemma from guinea pig was tested. It was found that verapamil (10^?6 to 10^?5 M) inhibited calcium binding to a great extent. Bepridil at the same concentrations was less potent than verapamil in the depression of calcium binding. Nifedipine and diltiazem did not affect sarcolemmal calcium binding. The differential action of the calcium antagonistic drugs was discussed.     

Negatively charged sites and calcium binding in the isolated rat heart sarcolemma*

Summary Colloidal iron staining, calcium binding and enzyme activities were studied in the isolated rat heart sarcolemma. Colloidal iron staining of the sarcolemma revealed a high density of negatively charged sites associated with the cell surface. This membrane fraction was found to have calcium binding activity at both low (0.1 mM) and high (1.25 mM) concentrations of calcium. Pretreatment of the sarcolemma with either trypsin, phospholipase C or neuraminidase, was associated with a reduction in colloidal iron staining as well as decreased calcium-binding activity at high concentrations of calcium. Calcium binding at low concentrations was decreased by both trypsin and neuraminidase. Mg²⁺ ATPase, Ca²⁺ ATPase, and Na⁺–K⁺ ATPase activities were altered by neuraminidase and trypsin treatments, whereas phospholipase C treatment altered Na⁺–K⁺ ATPase only. It is concluded that both surface negative charge and calcium-binding sites associated with the isolated rat heart sarcolemma are contributed by a mosaic of biomolecules including proteins, phospholipids and glycoproteins, and alterations in the surface charge may influence the activities of membrane-bound enzymes.Supported by MRC Studentship award.