亚急性衰老大鼠逼尿肌舒缩功能变化的实验研究

目的观察D—gal致亚急性衰老大鼠膀胱逼尿肌舒缩功能的变化。方法在初筛合格的sD大鼠颈背部皮下注射浓度为5％的D—gaI生理盐水溶液125mg·kg^-1·d^-1连续8周。用离体逼尿肌条实验观察动物逼尿肌舒缩功能,并进行组织病理形态学观察。结果与正常对照组比较,模型组动物逼尿肌自发性收缩频率加快（P〈0．01）．顺应性、弹力下降（P〈0．05～0．01）,但收缩性没有明显改变（P〉0．05）;ATP对亚急性衰老逼尿肌中的收缩作用增强,ISO在亚急性衰老动物逼尿肌中的抑制收缩作用减弱（P〈0．05～0．01）;病理形态学观察显示,模型动物膀胱形态改变明显,逼尿肌中胶原纤维组织所占比例增加（P〈0．01）。结论亚急性衰老大鼠逼尿肌舒缩功能及神经受体敏感性发生显著改变。     

Transient receptor potential A1 (TRPA1) activity in the human urethra--evidence for a functional role for TRPA1 in the outflow region

Background

A role for the transient receptor potential (TRP) A1 ion channel in rat lower urinary tract (LUT) sensation and disease has been proposed, but in the human LUT no information on TRPA1 activity is available.

Objectives

To investigate the distribution of TRPA1 in the human urethra and to study the effect of TRPA1 agonists on isolated urethral strip preparations.

Design, settings, and participants

Urethral specimens were obtained preoperatively from 10 patients and were freshly prepared for Western blot, immunohistochemistry, and functional in vitro investigations.

Measurements

The expression patterns of TRPA1 were studied with Western blot and immunohistochemistry. The effects of allyl isothiocyanate (AI), cinnamaldehyde (CA), and NaHS (donor of H₂S) on tension of urethral strips were investigated in tissue baths.

Results and limitations

TRPA1 immunoreactivity (-IR) was found in nerve fibres in the suburothelial space and was also located to nerve fibres of the muscle layer. Single TRPA1-IR nerves extended into the urothelium. A majority, but not all TRPA1-IR nerves also expressed immunoreactivity for CGRP or TRPV1. In the urothelium, TRPV1 was located to the outer layers whereas TRPA1 was observed in basal urothelial cells. Interspersed between strands of smooth muscle cells of the urethral wall, TRPA1- and vimentin-IR cells containing central nuclei and slender cytoplasmatic extensions were observed.In functional experiments, TRPA1-agonists had no contractile effect in urethral preparations. After precontraction with phenylephrine, AI, CA, and NaHS caused concentration-dependent relaxations of urethral strip preparations.

Conclusions

The localization of TRPA1 to nerves that also express TRPV1 and CGRP, and in urothelial cells and interstitial cells, as well as the findings that TRPA1 agonists can modify tone of urethral preparations, propose a role for TRPA1 in afferent and efferent sensory signaling of the human outflow region.     

放松训练对康复期精神分裂症患者的对照研究

目的探讨放松训练对康复期精神分裂症患者的治疗效果。方法将120例康复期精神分裂症患者,随机分为两组即实验组和对照组。两组在接受常规治疗和护理的同时,实验组进行3个月的放松训练。采用简明精神病评定量表（BPRS）、社会功能缺陷筛选量表（SDSS）和日常生活能力量表（ADL）对放松前和放松后3个月进行量化评定。结果放松训练3个月后实验组BPRS、SDSS及ADL评分明显低于对照组（P〈0.01）。结论放松训练技术能改善精神分裂症患者社会功能和日常生活能力,对于提高生活质量,延缓衰退,促进疾病的恢复很有帮助,值得在精神科推广。     

Temporal dissociation of frequency-dependent acceleration of relaxation and protein phosphorylation by CaMKII

Frequency-dependent acceleration of relaxation (FDAR) is an important intrinsic mechanism that allows for diastolic filling of the ventricle at higher heart rates, yet its molecular mechanism is still not understood. Previous studies showed that FDAR is dependent on functional sarcoplasmic reticulum (SR) and can be abolished by phosphatase or by Ca/CaM kinase (CaMKII) inhibition. Additionally, CaMKII activity/autophosphorylation has been shown to be frequency-dependent. Thus, we tested the hypothesis that CaMKII phosphorylation of SR Ca(2+)-handling proteins (Phospholamban (PLB), Ca(2+) release channel (RyR)) mediates FDAR. Here we show that FDAR occurs abruptly in fluo-4 loaded isolated rat ventricular myocytes when frequency is raised from 0.1 to 2 Hz. The effect is essentially complete within four beats (2 s) with the tau of [Ca(2+)](i) decline decreasing by 42+/-3%. While there is a detectable increase in PLB Thr-17 and RyR Ser-2814 phosphorylation, the increase is quantitatively small (PLB<5%, RyR approximately 8%) and the time-course is clearly delayed with regard to FDAR. The low substrate phosphorylation indicates that pacing of myocytes only mildly activates CaMKII and consistent with this CaMKIIdelta autophosphorylation did not increase with pacing alone. However, in the presence of phosphatase 1 inhibition pacing triggered a net-increase in autophosphorylated CaMKII and also greatly enhanced PLB and RyR phosphorylation. We conclude that FDAR does not rely on phosphorylation of PLB or RyR. Even though CaMKII does become activated when myocytes are paced, phosphatases immediately antagonize CaMKII action, limit substrate phosphorylation and also prevent sustained CaMKII autophosphorylation (thereby suppressing global CaMKII effects).     

CaMKII inhibition targeted to the sarcoplasmic reticulum inhibits frequency-dependent acceleration of relaxation and Ca2+ current facilitation

Cardiac Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) in heart has been implicated in Ca(2+) current (I(Ca)) facilitation, enhanced sarcoplasmic reticulum (SR) Ca(2+) release and frequency-dependent acceleration of relaxation (FDAR) via enhanced SR Ca(2+) uptake. However, questions remain about how CaMKII may work in these three processes. Here we tested the role of CaMKII in these processes using transgenic mice (SR-AIP) that express four concatenated repeats of the CaMKII inhibitory peptide AIP selectively in the SR membrane. Wild type mice (WT) and mice expressing AIP exclusively in the nucleus (NLS-AIP) served as controls. Increasing stimulation frequency produced typical FDAR in WT and NLS-AIP, but FDAR was markedly inhibited in SR-AIP. Quantitative analysis of cytosolic Ca(2+) removal during [Ca(2+)](i) decline revealed that FDAR is due to an increased apparent V(max) of SERCA. CaMKII-dependent RyR phosphorylation at Ser2815 and SR Ca(2+) leak was both decreased in SR-AIP vs. WT. This decrease in SR Ca(2+) leak may partly balance the reduced SERCA activity leading to relatively unaltered SR-Ca(2+) load in SR-AIP vs. WT myocytes. Surprisingly, CaMKII regulation of the L-type Ca(2+) channel (I(Ca) facilitation and recovery from inactivation) was abolished by the SR-targeted CaMKII inhibition in SR-AIP mice. Inhibition of CaMKII effects on I(Ca) and RyR function by the SR-localized AIP places physical constraints on the localization of these proteins at the junctional microdomain. Thus SR-targeted CaMKII inhibition can directly inhibit the activation of SR Ca(2+) uptake, SR Ca(2+) release and I(Ca) by CaMKII, effects which have all been implicated in triggered arrhythmias.     

Insights into the kinetics of Ca2+-regulated contraction and relaxation from myofibril studies

Muscle contraction results from force-generating interactions between myosin cross-bridges on the thick filament and actin on the thin filament. The force-generating interactions are regulated by Ca²⁺ via specialised proteins of the thin filament. It is controversial how the contractile and regulatory systems dynamically interact to determine the time course of muscle contraction and relaxation. Whereas kinetics of Ca²⁺-induced thin-filament regulation is often investigated with isolated proteins, force kinetics is usually studied in muscle fibres. The gap between studies on isolated proteins and structured fibres is now bridged by recent techniques that analyse the chemical and mechanical kinetics of small components of a muscle fibre, subcellular myofibrils isolated from skeletal and cardiac muscle. Formed of serially arranged repeating units called sarcomeres, myofibrils have a complete fully structured ensemble of contractile and Ca²⁺ regulatory proteins. The small diameter of myofibrils (few micrometres) facilitates analysis of the kinetics of sarcomere contraction and relaxation induced by rapid changes of [ATP] or [Ca²⁺]. Among the processes studied on myofibrils are: (1) the Ca²⁺-regulated switch on/off of the troponin complex, (2) the chemical steps in the cross-bridge adenosine triphosphatase cycle, (3) the mechanics of force generation and (4) the length dynamics of individual sarcomeres. These studies give new insights into the kinetics of thin-filament regulation and of cross-bridge turnover, how cross-bridges transform chemical energy into mechanical work, and suggest that the cross-bridge ensembles of each half-sarcomere cooperate with each other across the half-sarcomere borders. Additionally, we now have a better understanding of muscle relaxation and its impairment in certain muscle diseases.     

Antispasmodic and relaxant effects of the hidroalcoholic extract of Pimpinella anisum (Apiaceae) on rat anococcygeus smooth muscle

The present work describes the mechanisms involved in the muscle relaxant effect of ethanol:water (40:60, 60:40 and 80:20) aerial parts extracts of Pimpinella anisum. Three hidroalcoholic extracts in which the proportion of ethanol was 40% (HA(40%)), 60% (HA(60%)) or 80% (HA(80%)) were tested for activity in the rat anococcygeus smooth muscle. The three extracts (50 microg/mL) inhibited acetylcholine-induced contraction. The extract HA(60%) (5-50 microg/mL) concentration dependently relaxed acetylcholine-pre-contracted tissues (31.55+/-3.56%). Conversely, HA(40%) and HA(80%) did not exert relaxant action. Pre-incubation of the preparations with N(G)-nitro-L-arginine methyl ester (L-NAME, 100 microM), 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ, 3 microM) and oxyhemoglobin (10 microM) reduced the relaxation induced by HA(60%) (percentage of relaxation: 6.81+/-1.86%, 13.13+/-5.87% and 2.12+/-1.46%, respectively). Neither indomethacin (10 microM) nor tetraethylammonium (1 mM) affected the relaxation induced by HA(60%). Incubation of the tissues with L-NAME significantly enhanced the maximal contraction induced by acetylcholine, indicating an inhibitory role for NO in the modulation of the contractile response of anococcygeus smooth muscle to acetylcholine. However, simultaneous addition of L-NAME and HA(60%) resulted in an effect similar to that observed with L-NAME alone, further confirming the observation that Pimpinella anisum acts by realizing NO. Additionally, HA(60%) did not alter CaCl(2)-induced contraction. Collectively, our results provide functional evidence that the effects elicited by the hidroalcoholic extract of Pimpinella anisum involve the participation of NO and subsequent activation of the NO-cGMP pathway. The relaxant action displayed by Pimpinella anisum justifies its use in the folk medicine as an antispasmodic agent.     

In vivo assessment of safety and mechanisms underlying in vitro relaxation induced by Mikania laevigata Schultz Bip. ex Baker in the rat trachea

Mikania laevigata, popularly known in Brazil as "guaco", is largely used in folk medicine against respiratory diseases. However, neither the assessment of the toxicity of "guaco" syrup (GS, used by humans) nor its efficacy or mechanisms of action has been properly investigated. Using in vitro procedures, we showed that the hydroalcoholic extract (HE) from Mikania laevigata induces a concentration-dependent relaxation of rat trachea which does not depend on epithelium-derived substances but involves changes in the cellular mobilization of calcium, perhaps due to a direct effect on membrane potassium channels. In addition, we assessed both oral and intraperitoneal acute toxicity, as well as the oral subchronic and chronic toxicity of GS containing controlled amounts of coumarin, the main biological marker of Mikania laevigata preparations used in humans. The calculated LD(50) of GS after intraperitoneal administration was 0.904 g/kg in mice (both sexes) and 0.967 and 0.548 g/kg in male and female rats, respectively. However, the LD(50) values of GS by the oral route were calculated to be up to 10 g/kg, in both male and female mice and rats. Repeated dose 28- or 90-day oral treatment with GS (75, 150 and 300 mg/kg) did not produce any disturbances in the hematological or biochemical parameters of either male or female rats, nor did it provide evidence of toxicity in the hepatic, renal or pancreatic systems. Besides the mechanistic findings, our results provide evidence of the safety of Mikania laevigata in rodents, even after subchronic and chronic administration, at least in relation to the evaluated parameters.     

放松功对老年高血压患者保健效果的研究

目的探讨放松功对老年高血压患者的保健效果。方法对自愿受试的老年高血压患者进行放松功锻炼，通过对照研究，观测其高血压的治疗效果。结果放松功治疗组患者血压下降水平明显优于对照组（P〈O．05），症状改善效果尤佳。非药物治疗的5例高血压典型病例也取得较好的疗效。结论放松功作为老年高血压患者的辅助疗法，具有积极的保健效果。