Myotonic dystrophy is a muscular disorder characterized by muscle weakness and myotonia. Myotonia manifests with abnormally slow relaxation after strong voluntary contraction of the muscles. In our previous study we reported that quinine sulfate provided therapeutic benefit to myotonia and a home exercise program based on muscle strengthening exercises improved muscle strength. The purpose of this study was to determine the effect of a multi-therapeutic program in patients with myotonic dystrophy. For six months, seven patients with myotonic dystrophy received heat therapy, were given psychologic intervention using relaxation techniques, were trained at home, and were given quinine sulfate. The changes in muscle strength and relaxation time between the post-six-months home exercise program combined with quinine sulfate therapy, and the post-six months multi-therapeutic program, were assessed from the first dorsal interossei, the elbow flexors, and the knee extensors. The results were as follows: 1) The mean muscle strength of the each of the three muscles after the six months multi-therapeutic program was improved but was not significant compared with the post-six-months home exercise program combined with quinine sulfate therapy. 2) The mean relaxation time of each of the three muscles after the six months multi-therapeutic program was significantly reduced compared with the home exercise program combined with quinine sulfate therapy. In conclusion, the multi-therapeutic program undertaken in this study was the better program for the patients with myotonic dystrophy.
Adolescent ; Adult ; Female ; Heat/therapeutic use ; Human ; Male ; Middle Age ; *Muscle Relaxation ; Muscles/*physiopathology ; Myotonic Dystrophy/*physiopathology/*rehabilitation ; Relaxation Techniques ; Support, Non-U.S. Gov't ; Time Factors

In the heart, Na+-Ca2+ exchange (NCX) is the major Ca2+ extrusion mechanism. NCX has been considered as a relaxation mechanism, as it reduces global [Ca2+]i raised during activation. However, if NCX locates in the close proximity to the ryanodine receptor, then NCX would curtail Ca2+ before its diffusion to global Ca2+i. This will result in a global [Ca2+]i decrease especially during its ascending phase rather than descending phase. Therefore, NCX would decrease the myocardial contractility rather than inducing relaxation in the heart. This possibility was examined in this study by comparing NCX-induced extrusion of Ca2+ after its release from SR in the presence and absence of global Ca2+i transient in the isolated single rat ventricular myocytes by using patch-clamp technique in a whole-cell configuration. Global Ca2+i transient was controlled by an internal dialysis with different concentrations of BAPTA added in the pipette. During stimulation with a ramp pulse from +100 mV to -100 mV for 200 ms, global Ca2+i transient was suppressed only mildly, and completely at 1 mmol/L, and 10 mmol/L BAPTA, respectively. In these situations, ryanodine-sensitive inward NCX current was compared using 100micromol/L ryanodine, Na+ depletion, 5 mmol/L NiCl2 and 1micromol/L nifedipine. Surprisingly, the result showed that the ryanodine-sensitive inward NCX current was well preserved after 10 mmol/L BAPTA to 91 % of that obtained after 1 mmol/L BAPTA. From this result, it is concluded that most of the NCX-induced Ca2+ extrusion occurs before the Ca2+ diffuses to global Ca2+i in the rat ventricular myocyte.
Animals ; Architectural Accessibility ; Dialysis ; Diffusion* ; Heart ; Muscle Cells* ; Nifedipine ; Patch-Clamp Techniques ; Rats* ; Relaxation ; Ryanodine ; Ryanodine Receptor Calcium Release Channel

Mindfulness is a process in which all thoughts, feelings, sensations, and all phenomena that happen to me are uncritically recognized as they are, so that they are eventually accepted and released without identifying or automatically responding to them. The clinical effects of mindfulness-based therapy have already been demonstrated in several studies. However, consistent results have not been reported for the mechanism of mindfulness-based treatment. Thus, this review aimed to describe a systematic review of the literature and research on the mechanisms of mindfulness-based interventions. Experienced meditators showed a physiological change in a ‘wakeful hypometabolic state’ during mindfulness meditation. In mindfulness meditation, it is known that certain areas other than brain activation during relaxation are additionally activated, particularly activation of fronto-limbic and fronto-parietal neural networks. The psychological mechanisms include meta-cognitive awareness, emotion regulation, reduction of automatic and self-referential thinking, concentration control, self-compassion, improvement of value clarification and self-regulation, exposure, extinction, and reconsolidation. Of the brain regions with changes in activity associated with mindfulness meditation, prefrontal cortex, the default mode network including cortical midline structures were associated with emotion regulation, concentration control, and reduction of automatic and self-referential thinking. In addition, brain regions associated with mindfulness meditation have been reported in the hippocampus, amygdala, and medical frontal cortices associated with memory reconsolidation and fear extinction. Thus, mindfulness-based interventions have a psychological and neurobiological effect with a special mechanism different from other psychological interventions, so that mindfulness based intervention can be an effective therapeutic intervention with a different mechanism from other psychological techniques.
Amygdala ; Brain ; Frontal Lobe ; Hippocampus ; Meditation ; Memory ; Mindfulness ; Prefrontal Cortex ; Psychological Techniques ; Relaxation ; Self-Control ; Sensation ; Thinking

An impaired smooth muscle cell (SMC) relaxation of coronary artery by alteration of K+ channels would be the most potential explanation for reduced coronary reserve in left ventricular hypertrophy (LVH), however, this possibility has not been investigated. We performed morphometrical analysis of the coronary artery under electron microscopy and measured Ca2+-activated K (KCa) currents and delayed rectifier K (Kdr) currents by whole-cell and inside-out patch-clamp technique in single coronary arterial SMCs from rabbits subjected to isoprenaline-induced cardiac hypertrophy. Coronary arterial SMCs underwent significant changes in ultrastructure. The unitary current amplitude and the open-state probability of KCa channel were significantly reduced in hypertrophy without open-time and closed-time kinetic. The concentration-response curve of KCa channel to Ca2+ is shifted to the right in hypertrophy. The reduction in the mean single channel current and increase in the open channel noise of KCa channel by TEA were more sensitive in hypertrophy. Kdr current density is significantly reduced in hypertrophy without activation and inactivation kinetics. The sensitivity of Kdr current on 4-AP is significantly increased in hypertrophy. This is the first study to report evidence for alterations of KCa channels and Kdr channels in coronary SMCs with LVH. The findings may provide some insight into mechanism of the reduced coronary reserve in LVH.
Cardiomegaly* ; Coronary Vessels* ; Hypertrophy ; Hypertrophy, Left Ventricular ; Kinetics ; Microscopy, Electron ; Myocytes, Smooth Muscle ; Noise ; Patch-Clamp Techniques ; Rabbits ; Relaxation ; Tea

The present study was designed to evaluate the possible beneficial effects of biofeedback-assisted relaxation to pharmacotherapy on blood pressure and heart rate in patients with essential hypertension. Twenty patients with essential hypertension and without any complications or end-organ damage participated in the study. All the patients were using anti-hypertensive drugs. The study protocol consisted of an interview, 10 days baseline, 10 biofeedback-assisted relaxation sessions and a 10-day post-treatment period. Interview blood pressure (BP) and heart rate (HR) measurements, baseline mean values of systolic blood pressure (SBP), diastolic blood pressure (DBP) and HR recorded during the 1st, 10th and 20th minutes of each session and the post-treatment mean values were evaluated. Significant differences were found between the mean values of SBP, DBP and HR after the whole treatment protocol (Wilcoxon signed-ranks test). The mean values of SBP, DBP and HR measurements recorded during the 1st, 10th and 20th minutes of the biofeedback-assisted relaxation sessions, which were evaluated by repeated measures of ANOVA on ranks test, showed a significant decrease only for the 10th minute values at the end of the whole treatment program. Despite a short follow-up, it was suggested that these results were encouraging considering the fact that once the patients are thoroughly instructed in home practice of relaxation and encouraged to develop their own strategies for relaxation, the long term outcome may also be promising.
Adult ; Aged ; Biofeedback (Psychology)* ; Blood Pressure/drug effects* ; Female ; Follow-Up Studies ; Heart Rate/drug effects* ; Human ; Hypertension/therapy* ; Male ; Middle Age ; Relaxation Techniques*

OBJECTIVE: Papaverine has been used in treating vasospasm following subarachnoid hemorrhage(SAH). However, its action mechanism for cerebral vascular relaxation is not clear. Potassium channels are closely related to the contraction and relaxation of cerebral smooth muscle. Therefore, to identify the role of potassium and calcium channels in papaverine-induced vascular relaxation, we examine the effect of papaverine on potassium channels in freshly isolated smooth muscle cells from rat basilar artery. METHODS: The isolation of rat basilar smooth muscle cells was performed by special techniques. The whole cell currents were recorded by whole cell patch clamp technique in freshly isolated smooth muscle cells from rat basilar artery. Papaverine was added to the bath solution. RESULTS: Papaverine of 100 microM into bath solution increased the amplitude of the outward K+ current which was completely blocked by BKCa(large conductance calcium dependent potassium channels)blocker, IBX(iberiotoxin), and calcium chealator, BAPTA(1, 2-bis(o-aminophenoxy)ethane-N, N, N', N'-tetraacetic acid), in whole cell mode. CONCLUSION: These results strongly suggest that potassium channels may play roles in papaverine-induced vascular relaxation in rat basilar artery.
Animals ; Basilar Artery ; Baths ; Calcium ; Calcium Channels ; Muscle, Smooth* ; Myocytes, Smooth Muscle* ; Papaverine* ; Patch-Clamp Techniques ; Potassium ; Potassium Channels ; Rats* ; Relaxation

PURPOSE: beta-adrenoceptors have been demonstrated in human corporal smooth muscles by the receptor binding assays, and have been known to elicit relaxation of the precontracted corporal tissues. Despite these findings, it is not clear whether the beta-adrenoceptors have any role in the control of penile erection. Potassium channels play an important role in the physiology of the corporal smooth muscle. The maxi-K+ channel subtypes are thought to be the most physiologically relevant K+ channels expressed in this tissue. The goal of this study was to clarify the contribution of the beta-adrenoceptors to the modulation of the corporal smooth muscle tone. MATERIALS AND METHODS: Patch-clamp technique was applied to the cultured human corporal smooth muscle cells. RESULTS: Maxi-K+ channel was activated by the application of the beta-adrenoceptor stimulator, isoproterenol (ISO). ISO increased the open probability (nP0) by 512+/-53% and the mean open time by 214+/-12% in the cell-attached patch recording. The whole cell patch recording indicated that the application of ISO in the bath solution increased the peak amplitude of the whole cell outward K+-current during the step depolarization (from -70 to + 130 mV). The presence of a specific protein kinase A inhibitor (PKI) in the pipette tip suppressed the ISO-induced increase of the whole cell outward K+-current. CONCLUSIONS: These studies showed that the beta-adrenoceptor activation contributed to the modulation of the corporal smooth muscle tone by activating the potassium channels, and moreover, that the activation of the potassium channels by the beta-adrenoceptors was related to the protein kinase A pathway.
Baths ; Cyclic AMP-Dependent Protein Kinases ; Humans* ; Isoproterenol ; Male ; Muscle, Smooth* ; Myocytes, Smooth Muscle* ; Patch-Clamp Techniques ; Penile Erection ; Physiology ; Potassium Channels ; Relaxation

AIMTo evaluate the relaxant effect of verapamil on human corpus cavernosum in vitro and to assess the drug's potential as a treatment for erectile dysfunction (ED).

METHODSPreparations of the human corpus cavernosum were obtained from recently deceased young men who had had normal erectile function. The isometric tension and detailed curves were recorded when contractions induced by 10 micromol/L phenylephrine were reduced by different doses of verapamil or the vehicle control (sterile water). The tension of human corpus cavernosum preparations are described as a percentage of their top tension before adding verapamil or the vehicle. ANOVA and least significant difference tests were used for statistical analysis.

RESULTSDoses of 1 micromol/L, 10 micromol/L and 100 micromol/L verapamil resulted in relaxation of (35.28+/-7.96)%, (55.91+/-6.41)%, (85.68+/-4.16)% after 30 min, respectively. The vehicle control at the same time point produced relaxation of (-0.06+/-10.57)% (P<0.05).

CONCLUSIONVerapamil is significantly effective in relaxing normal human corpus cavernous smooth muscle induced by phenylephrine in vitro and the relaxant effect depends on the concentration of verapamil.

Adult ; Humans ; In Vitro Techniques ; Male ; Muscle Relaxation ; drug effects ; Muscle, Smooth, Vascular ; drug effects ; physiology ; Penis ; drug effects ; physiology ; Verapamil ; pharmacology

OBJECTIVETo investigate the effect of ascorbic acid (VC) on relaxation of ex vivo Bufo gastrocnemius during sustained isometric contraction.

METHODSDynamic tension of the muscle was recorded under constant voltage stimulation within 7.0 min at 2 s intervals. The rest tension and relaxation rate of the muscle was obtained by weighted fitting to the relaxation process of tension <90% of its peak with a mono-exponential model to characterize the muscular relaxation.

RESULTSVC at 2.0 mmol/L alone or in combination with the inhibitors of the antixoidation enzymes (surperoxide dismutase, glutathione peroxidase and catalase) resulted in negligible alterations in the muscular relaxation kinetics. VC combined with the inhibitor of surperoxide dismutase resulted in significantly lowered relaxation rate while increased rest tension, but VC with the inhibitor of either catalase or glutathione peroxidase showed negligible action. VC combined with the inhibitors of all the 3 enzymes also caused significant effect on the muscular relaxation kinetics, which was similar the effect of VC with superoxide dismutase inhibitor.

CONCLUSIONVC at high concentration may result in oxidative toxicity to the biological system rich in transitional metal ion complexes but with low antioxidation capacity by causing superoxide-mediated oxidative damages.

Animals ; Ascorbic Acid ; pharmacology ; Bufonidae ; Electric Stimulation ; In Vitro Techniques ; Isometric Contraction ; drug effects ; Muscle Relaxation ; drug effects ; Muscle, Skeletal ; drug effects ; physiology

There was a slow-relaxing tail of skeletal muscles in vitro upon the inhibition of Ca(2+)-pump by cyclopiazonic acid (CPA). Herein, a new linearly-combined bi-exponential model to resolve this slow-relaxing tail from the fast-relaxing phase was investigated for kinetic analysis of the isometric relaxation process of Bufo gastrocnemius in vitro, in comparison to the single exponential model and the classical bi-exponential model. During repetitive stimulations at a 2-s interval by square pulses of a 2-ms duration at 12 V direct currency (DC), the isometric tension of Bufo gastrocnemius was recorded at 100 Hz. The relaxation curve with tensions falling from 90% of the peak to the 15th datum before next stimulation was analyzed by three exponential models using a program in MATLAB 6.5. Both the goodness of fit and the distribution of the residuals for the best fitting supported the comparable validity of this new bi-exponential model for kinetic analysis of the relaxation process of the control muscles. After CPA treatment, however, this new bi-exponential model showed an obvious statistical superiority for kinetic analysis of the muscle relaxation process, and it gave the estimated rest tension consistent to that by experimentation, whereas both the classical bi-exponential model and the single exponential model gave biased rest tensions. Moreover, after the treatment of muscles by CPA, both the single exponential model and the classical bi-exponential model yielded lowered relaxation rates, nevertheless, this new bi-exponential model had relaxation rates of negligible changes except much higher rest tensions. These results suggest that this novel linearly-combined bi-exponential model is desirable for kinetic analysis of the relaxation process of muscles with altered Ca(2+)-pumping activity.
Animals ; Bufonidae ; physiology ; Electric Stimulation ; Electrophysiology ; In Vitro Techniques ; Indoles ; pharmacology ; Kinetics ; Models, Animal ; Models, Biological ; Muscle Relaxation ; drug effects ; physiology ; Muscle Tonus ; drug effects