卡托普利对自发性高血压大鼠血管平滑肌细胞增殖及癌基因和抑癌基因的影响

目的：观察卡托普利（CaP）对自发性高血压大鼠（SHR）血管平滑肌细胞（VSMC）增殖的作用及对原癌基因及抑癌基因的影响。方法：氚-胸腺嘧啶核苷（3H－TdR）参入，电镜，原位来交及Northernblot杂交。结果：CaP在降低SHR血压同时，能减少VSMC的线粒体，粗面内质网及3H－TdR参入量（P<0.01），并能逆转c－fos，c－myc，c－sis原癌基因mRNA表达增强（P<0.05或0.01），p53抑癌基因mRNA表达减弱（P＜0．01）。结论：Cap能抑制SHR的VSMC增殖，与癌基因调控的分子生物学机制有关。     

Muscle glycogen repletion from endogenous carbon sources during recovery from high intensity exercise in the fasted rat

During recovery from high intensity exercise, substantial and rapid muscle glycogen repletion from endogenous carbon sources is reported in a variety of vertebrate species, the rat being the only reported exception. The major aim of this study was to re-examine the process of glycogen repletion during recovery from high intensity exercise in the rat. In response to 3 min of vigorous swimming, muscle glycogen concentrations decrease markedly from initial levels of 20.2±1.5 and 21.2±0.9 μmol g^-1 to 6.4±1.1 and 7.9±1.4 μmol g^-1 in the tibialis anterior and plantaris muscles respectively. The equivalent of 58% of the glycogen carbons mobilized during exercise by the plantaris and 73% of that mobilized by the tibialis anterior muscle is repleted within 1 h following exercise. Using the hepatectomized rat as experimental model, a secondary aim of the study was to evaluate whether the liver is essential for the repletion of muscle glycogen. Although the absence of significant differences in the magnitude of post-exercise muscle glycogen repletion between sham-operated and hepatectomized rats suggests that the resynthesis of muscle glycogen can take place in the absence of hepatic gluconeogenesis, the present study identifies several limitations in the use of acute hepatectomy. Overall, the present study indicates that, in contrast to published views, the rat resembles other vertebrates in that it can support extensive muscle glycogen repletion from endogenous carbon sources during the recovery phase following high intensity exercise.     

Modulation of ryanodine-induced contractures in human skeletal muscle pretreated with dantrolene

Dantrolene seems to be the causal therapy in malignant hyperthermia (MH) crisis but the complex mechanisms of MH and dantrolene therapy are still not fully understood. The influence of dantrolene on ryanodine-induced contractures has been reported in animal studies only. In the present study 20 patients from] 7 families were tested for MH using the protocol of the European Malignant Hyperthermia Group. In addition ryanodine-induced contractures were evaluated following bolus application of 10.0 μmol · 1^-1 ryanodine. After pretreatment with 1 μimol · 1^-1 dantrolene ryanodine-provoked contractures developed significantly later in MHS (15.8±1.8 min) and MHN (46.0±4.2 min) muscle specimens than after ryanodine alone (MHS 4.8±0.7 min), (MHN 13.7±0.9 min). They were no longer observed in either group after pretreatment with 5 μimol · 1^-1 dantrolene. We conclude that dantrolene is able to attenuate ryanodine-induced contractures dose-dependendy, and therefore it is speculated that dantrolene could specifically act at the ryanodine receptor binding site.     

上腔静脉梗阻外科治疗(附5例报告)

本文通过应用大隐静脉、人造血管与经戊二醛处理后的新生儿脐带静脉,分别为5例上腔静脉梗阻进行6例次转流术或上腔静脉重建术,认为脐带静脉具有取材容易,处理简单,血管口径一致,无静脉瓣,缝合较易等优点;大隐静脉适用于不开胸者,为减轻症状治疗首选材料;人造血管不宜代上腔静脉。上腔静脉梗阻手术治疗指征是,当梗阻发生在奇静脉或其以上,侧枝循环少,左右无名静脉通畅,病人有不能耐受的脑部和呼吸道症状,估计能够耐受开胸手术。     

心肌和骨骼肌对低血钙不同反应性机理的初步研究

本实验采用枸椽酸钠等静脉输入复制家兔低血钙。实验动物血钙显著下降,同时出现骨骼肌抽搐和心肌收缩性下降。测定骨骼肌匀浆钙含量在低血钙前、后均比心肌匀浆高。认为这两种肌肉细胞内固有钙含量的差异,是低血钙时骨骼肌收缩亢进和心肌收缩性下降的原因之一,其次为神经肌肉的兴奋性改变。     

Effects of bile acids on ventricular muscle contraction and electrophysiological properties: studies in rat papillary muscle and isolated ventricular myocytes

Summary The effects of sodium salts of various bile acids on the contractile force and the electrophysiological properties of rat ventricular muscle were studied in vitro. Primary, conjugated, and secondary bile acids were studied in a concentration range of 10^–9–10^–6 mol/l, which corresponds to concentrations found in the plasm of patients with cholestatic jaundice. In general, the bile acid induced a negative inotropic effect which was manifested as a reduction in active tension, maximum rate of tension activation, and maximum rate of tension relaxation. Twitch duration and time to peak tension were unaffected by the bile acids. The negative inotropism was associated with a reduction in ventricular action potential duration. Resting potential, action potential amplitude, and maximum upstroke velocity of phase 0 depolarization were unaffected. Voltage clamp experiments in rat ventricular myocytes demonstrated that sodium taurocholate decreased the slow inward current and slightly increased the outward potassium current. Hence, these effects on the membrane currents are probably responsible for the negative inotropic effect. Send offprint requests to O. Binah at the above address     

A new modification in temporary stent technique of microvenous anastomosis — An experimental study

Summary A new modification of microvenous anastomosis, which has increased patency rates while simultaneously decreasing the difficulty of the procedure, is presented in this paper. The primary purpose of this study was to compare the classical and the temporary stent techniques of microvenous anastomosis. Because of problems such as mixing and tangling of strings during insertion and tying of the last four sutures while applying the temporary stent technique, we decided to modify the procedure. The silastic tube was removed through an incision (venotomy), distant from the actual suture line. This modified technique and the other above mentioned techniques were carried out on rat femoral veins. The results indicate that this modification has increased patency rates, shortened the time of anastomosis and facilitated the procedure.     

精索静脉曲张患者精索静脉和外周血睾酮水平的对照研究

目的：探讨精索静脉血张患者血浆睾酮水平的变化及其机制。方法：对25例精索静脉曲张患者与22例腹股沟斜疝患者精索静脉和外周血睾酮水平进行对照研究。结果：精索静脉曲张组外周血睾酮浓度与腹股沟斜疝组无差别（P＞0．05），而精索静脉血睾酮浓度两组则有明显差异，精索静脉曲张组精索静脉血中睾酮浓度较腹股沟斜疝组低（P＜0．05）。结论：多种因素可影响外周血睾酮浓度，使其难以准确地反映睾丸分泌睾酮的实际水平，而精索静脉血中的睾酮浓度则能较为直接地反映睾丸的睾酮分泌能力。