毛冬青甲素对心脏功能和血流动力学的作用

在整体猫心脏实验表明毛冬青甲素能增强心叽收缩性,增加心输出量、动脉血压和外周血管阻力,轻度减慢心率,增加分钟张力——时间指数,以低效率的方式增加心脏作功;轻度改善心脏的舒张特性。离体豚鼠心脏制备也表明毛冬青甲素增强心脏收缩;该药的量效曲线与异丙肾上腺素的量效曲线不平行,且不受心得安(10~(-7)M)的影响而右移,提示该药的正性肌力作用可能是对心肌直接作用,并可能不是通过β受体而实现。毛冬青甲素与哇巴因合用,不影响豚鼠哇巴因LD100。本文报导了一种利用(dp/dt)/P曲线测取左室等容舒张期压力降低的时间常数(T)的简便可行方法。     

小儿化食口服液的药理学研究

报道了改革后新剂型—小儿化食口服液对动物的消化功能的影响(包括离体肠段的收缩性、小肠推进运动、胃蛋白酶活性等)。结果显示小儿化食口服液与原剂型小儿化食丸药理作用基本相似,且在对胃蛋白酶活性的影响等方面优于丸剂。本实验对该药剂型改革提供了药理学依据。     

Differential vascular effects of neuropeptide Y(NPY) selective receptor agonists

Neuropeptide Y (NPY) increases blood pressure either directly or indirectly by potentiating the effect of various vasoconstrictors. Only one (the Y₁-receptor) of two subtypes of receptors (Y₁ and Y₂) is thought to mediate the vascular smooth muscle contraction. To test this hypothesis we challenged isolated rat mesenteric arteries that had a functional endothelium with (1–36) NPY and with specific Y₁-receptor ([Leu³¹, Pro³⁴] NPY) and Y₂-receptor ([Ahx^5–24, -Glu²--Lys³⁰] NPY) agonists. The Y₁-receptor agonist elicited a contractile response similar to that of NPY, whereas the Y₂-receptor agonist had no effect on wall tension. We also found that the presence of a functional endothelium has no influence on the contractile response to NPY. From these data we conclude that the direct contractile effect of NPY in the mesenteric artery is mediated by stimulation of Y₁-receptors and is not endothelium-dependent.     

扶桑花乙酸乙酯溶物（HR—3）对心血管活动影响的初探

初步观察了扶桑花乙酸乙酯溶物（ＨＲ３）的抗心肌缺氧作用及对动物血压和离体蛙心的影响．实验表明：①ＨＲ３可使ＩＣＲ小鼠的常压耐缺氧时间显著延长（Ｐ＜０．０１）,该作用与心得安无明显差异;可以明显延长夹闭气管小鼠的心电消失时间和异丙肾上腺素处理的小鼠心肌耐缺氧时间,提示ＨＲ３能对抗心肌缺氧．②１００ｍｇ／ｋｇ以上的ＨＲ３能明显降低家兔的收缩压与舒张压,该降压作用不被阿托品阻断,但不影响心率．③ＨＲ３对离体蛙心的心率及振幅呈梯度抑制作用,且该作用是可逆的．提示ＨＲ３可能通过减弱心肌收缩力,而产生降压作用和对抗心肌缺氧．     

Protection by iloprost of the myocardial contractility and rhythmicity in frog ventricular strips

Summary Incubation of frog ventricular strips with Ringer containing iloprost for 24 h at 4°C can protect the contractility and rhythmicity from heat stimulation and aconitine when compared with strips incubated in Ringer alone under the same experimental conditions.The authors are grateful to Dr E. Schillinger, Schering Research Laboratories, Berlin, W.-Germany, for kindly supplying iloprost (ZK 36 374). This work was supported by a grant from the Turkish Scientific and Technical Research Council (TAG-480).     

Rheological behavior of mammalian cells

Rheological properties of living cells determine how cells interact with their mechanical microenvironment and influence their physiological functions. Numerous experimental studies have show that mechanical contractile stress borne by the cytoskeleton and weak power-law viscoelasticity are governing principles of cell rheology, and that the controlling physics is at the level of integrative cytoskeletal lattice properties. Based on these observations, two concepts have emerged as leading models of cytoskeletal mechanics. One is the tensegrity model, which explains the role of the contractile stress in cytoskeletal mechanics, and the other is the soft glass rheology model, which explains the weak power-law viscoelasticity of cells. While these two models are conceptually disparate, the phenomena that they describe are often closely associated in living cells for reasons that are largely unknown. In this review, we discuss current understanding of cell rheology by emphasizing the underlying biophysical mechanism and critically evaluating the existing rheological models. Received 25 May 2008; received after revision 19 June 2008; accepted 1 July 2008     

Hydrocortisone administration enhances vessel contractility in Koltushi low-, and Koltushi high-avoidance rats

The contractility of tail artery rings was investigated in rats psychogenetically selected for rapid (KHA) and slow (KLA) acquisition of an avoidance response in the shuttle box. The vessel contractility was greater in the KHA rats. Hydrocortisone administration enhanced vessel contractility in both strains.     

维生素B1及维生素C对酒精引起的心功能损伤的预防及修复作用

主要探讨了VB1及Vc对酒精引起的心功能损伤的预防及修复作用．将45只牛蛙随机分为三组；对照组、VB1组、Vc组．经后大静脉向各组牛蛙均灌入20％酒精对心脏进行损伤，4min后分别给予对照组、VBl组、Vc组牛蛙灌注任氏液、0．2g／L V B1溶液、0．6g／L Vc溶液，20min再次向各组牛蛙心脏灌入20％酒精，于每一次灌注溶液前后分别记录三组牛蛙的心率及心肌收缩力．结果显示，20％的酒精能够使牛蛙的心率减慢，心肌收缩力降低，0．2g／t．VB1，0．6g／LVC使牛蛙的心率及心肌收缩力明显恢复，并且VB，和Vc具有抗酒精损伤作用．可见，VB1及Vc对酒精引起的牛蛙心功能损伤具有一定的预防及修复作用．     

三种麻醉剂对蟾蜍离体心脏生理特性的影响

本实验采用蟾蜍离体心脏灌流方法分别观察了氨基甲酸乙酯、戊巴比妥钠、水合氯醛三种麻醉剂对心脏收缩性和百动节律性的影响．结果：对心率，三种麻醉剂均有抑制作用，其中氨基甲酸乙酯抑制作用最大，抑制率为27．1％；水合氯醛抑制作用次之，抑制率为18．9％；戊巴比妥钠抑制作用最小，抑制率为5．6％．去除麻醉剂后，氨基甲酸乙酯组能立即恢复正常，戊巴比妥钠组和水合氯醛组心率均不能立即恢复到正常水平．对心脏收缩力，三者均有较强的抑制作用。氨基甲酸乙酯对收缩力抑制率为26．0％，戊巴比妥纳为23．0％，水合氯醛为12．0％，去除麻醉剂后。氨基甲酸乙酯组和水合氯醛组较易恢复到正常水平，戊巴比妥钠组不易恢复。     

Intra-vascular glucocorticoid metabolism as a modulator of vascular structure and function

The ability of glucocorticoids to directly alter arterial function, structure and the inflammatory response to vascular injury may contribute to their well-established link with the development of cardiovascular disease. Recent studies have emphasised the importance of tissue-specific regulation of glucocorticoid availability by the 11 β-hydroxysteroid dehydrogenase (11HSD) isozymes, which inter-convert active glucocorticoids and their inactive metabolites. The expression of both type 1 and type 2 11HSDs in the arterial wall suggests that prereceptor metabolism of glucocorticoids may have a direct impact on vascular physiology. Indeed there is evidence that 11HSDs influence glucocorticoid-mediated changes in vascular contractility, vascular structure, the inflammatory response to injury and the growth of new blood vessels. Hence, inhibition of 11HSD isozymes may provide a novel therapeutic target in vascular disease. Received 19 September 2005; received after revision 1 November 2005; accepted 25 November 2005