To investigate the possible involvement of outward potassium (K+) currents in nitric oxide-induced relaxation in intestinal smooth muscle, we used whole-cell patch clamp technique in freshly dispersed guinea-pig ileum longitudinal smooth muscle cells. When cells were held at -60 mV and depolarized from - 40 mV to + 50 mV in 10 mV increments, sustained outward K+ currents were evoked. The outward K+ currents were markedly increased by the addition of 10 muM sodium nitroprusside (SNP). 10 muM S-nitroso-N-acetylpenicillamine (SNAP) and 1 mM 8-Bromo-cyclic GMP (8-Br-cGMP) also showed a similar effect to that of SNP. 1 mM tetraethylammonium (TEA) significantly reduced depolarization-activated outward K+ currents. SNP-enhanced outward K+ currents were blocked by the application of TEA. High EGTA containing pipette solution (10 mM) reduced the control currents and also inhibited the SNP-enhanced outward K+ currents. 5 mM 4-aminopyridine (4-AP) significantly reduced the control currents but showed no effect on SNP-enhanced outward K+ currents. 0.3 muM apamin and 10 muM glibenclamide showed no effect on SNP-enhanced outward K+ currents. 1 muM 1H-(1,2,4)oxadiazolo (4,3-a)quinoxaline-1-one (ODQ), a specific inhibitor of soluble guanylate cyclase, significantly blocked SNP-enhanced K+ currents. We conclude that NO donors activate the Ca2+-activated K+ channels in guinea-pig ileal smooth muscle via activation of guanylate cyclase.
4-Aminopyridine ; Apamin ; Egtazic Acid ; Glyburide ; Guanylate Cyclase ; Humans ; Ileum* ; Muscle, Smooth* ; Myocytes, Smooth Muscle* ; Nitric Oxide* ; Nitroprusside ; Potassium Channels, Calcium-Activated ; Potassium* ; Relaxation ; S-Nitroso-N-Acetylpenicillamine ; Tea ; Tetraethylammonium ; Tissue Donors

The present study were designed to characterize the action mechanisms of acetylcholine (ACh) -induced endothelium-dependent relaxation in arteries precontracted with high K (70 mM). For this, we simultaneously measured both muscle tension and cytosolic free Ca2 concentration ([Ca2 ]i), using fura-2, in endothelium-intact, rabbit carotid arterial strips. In the artery with endothelium, high K increased both [Ca2 ]i and muscle tension whereas ACh (10microM) significantly relaxed the muscle and increased [Ca2 ]i. In the presence of NG-nitro-L-arginine (L-NAME, 0.1 mM), ACh increased [Ca2 ]i without relaxing the muscle. In the artery without endothelium, high K increased both [Ca2 ]i and muscle tension although ACh was ineffective. 4-DAMP (10 nM) or atropine (0.1microM) abolished ACh-induced increase in [Ca2 ]i and relaxation. The increase of [Ca2 ]i and vasorelaxation by ACh was siginificantly reduced by either 3microM gadolinium, 10microM lanthanum, or by 10microM SKF 96365. These results suggest that in rabbit carotid artery, ACh-evoked relaxation of 70 mM K -induced contractions appears to be mediated by the release of NO. ACh-evoked vasorelaxation is mediated via the M3 subtype, and activation of the M3 subtype is suggested to stimulate nonselective cation channels, leading to increase of [Ca2 ]i in endothelial cells.
Acetylcholine ; Arteries ; Atropine ; Carotid Arteries* ; Cytosol ; Endothelial Cells ; Endothelium ; Fura-2 ; Gadolinium ; Lanthanum ; Muscle Tonus ; Nitric Oxide ; Nitroarginine ; Relaxation* ; Vasodilation

Tonic smooth muscle exhibit the latch phenomenon: high force at low myosin regulatory light chains (MRLC) phosphorylation, shortening velocity (Vo), and energy consumption. However, the kinetics of MRLC phosphorylation and cellular activation in phasic smooth muscle are unknown. The present study was to determine whether Ca(2+)-stimulated MRLC phosphorylation could suffice to explain the agonist- or high K(+)-induced contraction in a fast, phasic smooth muscle. We measured myoplasmic [Ca2+], MRLC phosphorylation, half-time after step-shortening (a measure of Vo) and contractile stress in rabbit urinary bladder strips. High K(+)-induced contractions were phasic at both 22degrees C and 37degrees C: myoplasmic [Ca2+], MRLC phosphorylation, 1/half-time, and contractile stress increased transiently and then all decreased to intermediate values. Carbachol (CCh)-induced contractions exhibited latch at 37degrees C: stress was maintained at high levels despite decreasing myoplasmic [Ca2+], MRLC phosphorylation, and 1/half-time. At 22degrees C CCh induced sustained elevations in all parameters. 1/half-time depended on both myoplasmic [Ca2+] and MRLC phosphorylation. The steady-state dependence of stress on MRLC phosphorylation was very steep at 37degrees C in the CCh- or K(+)-depolarized tissue and reduced temperature flattend the dependence of stress on MRLC phosphorylation compared to 37degrees C. These data suggest that phasic smooth muscle also exhibits latch behavior and latch is less prominent at lower temperature.
Carbachol ; Contracts ; Kinetics ; Muscle, Smooth ; Myosin Light Chains ; Phosphorylation ; Urinary Bladder

OBJECTIVE: It is a widely accepted belief that paraspinal muscles tend to show spontaneous activity on needle electromyography early on in a radiculopathy and distal muscles become abnormal later on. But most studies have shown the limitations of using symptom duration when interpreting electrodiagnostic findings in radiculopathy. The purpose of this study was to determine the relationship between symptom duration and abnormal spontaneous activity in S1 radiculopathy confined to abnormal H-reflex. METHOD: A retrospective study that collected the informations on symptom duration and spontaneous activity in paraspinal muscle and gastrocnemius for 112 patients with S1 radiculopathy diagnosed by unilateral H-reflex abnormality was undertaken. RESULTS: Abnormal spontaneous activity in paraspinal muscle had shown a significant negative correlation with symptom duration, that is a tendency to decrease its expression over symptom duration. On the contrary abnormal spontaneous activity in gastrocnemius muscle was rare at first a few weeks and became to show after 7 weeks. Patients with symptom duration over 1 year had higher incidence of having no abnormal spontaneous activities both in paraspinal and gastrocnemius muscle. CONCLUSION: These results suggested that symptom duration had a potential role in the diagnosis of S1 radiculopathy when H-reflex were abnormal unilaterally.
Diagnosis ; Electromyography ; H-Reflex ; Humans ; Incidence ; Muscle, Skeletal ; Muscles ; Needles ; Paraspinal Muscles ; Radiculopathy* ; Retrospective Studies

Background/Aims: This study was conducted to investigate the inhibitory effect of irsogladine maleate (IM) on gastric ulcers induced by ethanol and hydrochloric acid (HCl). Methods: Mice were pretreated with IM for 1 hours before ulcer induction. Gastric ulcers were induced by oral administration of an ethanol/HCl mixture. To clarify the action mechanism of IM, the roles of 3ʹ5ʹ-cyclic adenosine monophosphate (cAMP), nitric oxide (NO), adenosine triphosphate-sensitive potassium (KATP ) channels, prostaglandins and transient receptor potential cation channel subfamily V member 1 (TRPV1) were investigated, and lipid peroxidation in the stomach of IM-treated and -untreated animals was also measured. Results: IM significantly reduced the extent of ethanol/HCl mixture-induced gastric ulceration. It exhibited dose-related gastroprotection against the ethanol/ HCl-induced lesions, while pretreatment with glibenclamide but not N(ω)-nitro-L-arginine methyl ester, reversed this action. While pretreatment with the TRPV1 antagonist capsazepine failed to effectively block the gastroprotective effect of IM, the non-selective cyclooxygenase inhibitor indomethacin almost abolished it. IM also decreased the level of thiobarbituric acid reactive substances. Conclusions We concluded that IM exhibited significant gastroprotective effects in an ethanol/HCl-induced ulcer model, which appear to be mediated, at least in part, by NO, cAMP, endogenous prostaglandins, KATP channel opening, activation of TRPV1 channels, and antioxidant properties.

No abstract available.
Lipoma*

Primary aortoenteric fistula (PAEF) is a rare but catastrophic cause of gastrointestinal bleeding. The diagnosis of PAEF is difficult to make. The classic triad of symptoms, i.e. gastrointestinal bleeding, abdominal pain, and a pulsating abdominal mass is overemphasized, as it occurs in less than 11~25% of the patients. For two thirds of the patients, the diagnosis is made in the operating room. Endoscopic and radiographic studies are very helpful, but the absence of abnormalities can not exclude the diagnosis. PAEF is a clinical and surgical challenge associated with high mortality. A high index of suspicion, early diagnosis and prompt and appropriate surgical intervention are essential to patient survival. Two primary aortoenteric fistulas (aortoduodenal and aortoesophageal) cases are presented and the related literature are reviewed.
Abdominal Pain ; Aorta, Abdominal ; Aortic Aneurysm, Abdominal ; Early Diagnosis ; Fistula ; Gastrointestinal Hemorrhage ; Hemorrhage ; Humans ; Intestinal Fistula ; Operating Rooms ; Vascular Fistula

BACKGROUND: Patients with non-Q wave myocardial infarction tend to have smaller infarcts and less degree of ventricular function impairment initially, however, uncomplicated non-Q wave infarctions are known to be as serious as Q wave myocardal infarction due to residual myocardal ischemia and higher reinfarction rate. METHODS: Inorder to compare the clinical and coronary angiographic findings of Q wave infarction with those of non-Q wave infarction. 58 partients with acute myocardial infarction were reviewed retrospectively. Patients were classified into Q wave(n=45) and non-Q wave infarction(n=13) according to electrocardiographic findings. RESULTS: 1) There were no significant differences between the two groups in risk factors of coronary artery disease such as hypertension, hypercholesterolemia, smoking and diabets mellitus. 2) The peak myocardial enzyme levels of CPK, CPK-MB were significantly higher in the Q wave MI group, and the percentage of wall motion abnormality on two-dimensional echocardiography was significantly higher in Q wave MI than in the non-Q wave MI group. 3) The number of involved vessel, degree of stenosis and collateral circulation were not different but high degree of stenosis of infarct-related artery was more frequent in Q wave MI group. 4) There were no significant differences between the two groups in the incidence of arrhythmia and in-hospital mortality. CONCLUSION: There were some differences in clinical and angiographic findings, but in-hospital mortality was not significant different between two groups. Futher prospective studies should be performed to clarify the long term prognosis.
Arrhythmias, Cardiac ; Arteries ; Collateral Circulation ; Constriction, Pathologic ; Coronary Angiography ; Coronary Artery Disease ; Echocardiography ; Electrocardiography ; Hospital Mortality ; Humans ; Hypercholesterolemia ; Hypertension ; Incidence ; Infarction ; Ischemia ; Myocardial Infarction* ; Prognosis ; Retrospective Studies ; Risk Factors ; Smoke ; Smoking ; Ventricular Function

BACKGROUND: Propofol directly inhibits vascular reactivity. However, available information regarding the underlying mechanisms of propofol is poor. Therefore, mechanisms of the underlying relaxant action of propofol were investigated using rabbit renal arteries. METHODS: Propofol-induced relaxation of rabbit renal arteries was studied in contracted preparations with 50 mM KCl or 10microM histamine. Vessel tension was recorded with a pen recorder. We were interested in determining whether propofol-induced vasodilation is affected by endothelium-denudation, L-NG-nitroarginine methyl ester (L-NAME), tetraethylammonium (TEA), iberiotoxin, glibenclamide, 4-aminopyridine, 7-ethoxyresorufin, caffeic acid, baiclalein, ryanodine, and thapsigargin. RESULTS: Propofol-induced concentration-dependent vasodilation was not affected either by endothelium denudation or by L-NAME during histamine-induced contraction. The relaxing effect of propofol on histamine-induced contraction was inhibited by either TEA, a K+ channel inhibitor, or iberiotoxin (100 nM), a selective blocker of the large conductance Ca(2+)-activated K+ channel (BKCa channel). In contrast, the relaxing effect of propofol was unaffected by 10microM glibenclamide, an ATP-sensitive K+ channel blocker, by 5 mM 4-aminopyridine, a blocker of delayed rectifier, by 7-ethoxyresorufin, a cytochrome P450 inhibitor, by 10microM caffeic acid and 10microM baiclalein, lipooxygenase inhibitors, or by 10microM ryanodine and thapsigargin, Ca2+store inhibitors. CONCLUSIONS: These results suggest that the relaxant effect of propofol may result from activation of BKCa channels by inhibiting voltage-gated Ca2+ influx in a prolonged manner.
4-Aminopyridine ; Caffeic Acids ; Contracts ; Cytochrome P-450 Enzyme System ; Endothelium ; Glyburide ; Glycosaminoglycans ; Histamine ; NG-Nitroarginine Methyl Ester ; Oxazines ; Peptides ; Propofol ; Relaxation ; Renal Artery ; Ryanodine ; Tea ; Tetraethylammonium ; Thapsigargin ; Vasodilation

OBJECTIVE: Chronic subdural hematoma (CSDH) is one of the most common types of intra-cranial hemorrhages usually associated with trauma. Surgical treatment is the treatment of choice and burr hole trephination (BHT) is widely performed. The recurrence rate in the patients with CSDH is 3.7-30%. This study investigated the risk factors associated with the recurrence of patients with CSDH who underwent BHT. METHODS: One hundred twenty-five patients with CSDH underwent BHT. Eight of 125 patients (6.4%) underwent reoperation for recurrent CSDH. We retrospectively analyzed demographic, clinical and radiological findings, catheter tip location and drainage duration as the risk factors for the recurrence of CSDH. RESULTS: Recurrence of CSDH in the high- or mixed-density groups was significantly higher than those in the low- or iso-density groups (p<0.001). Placement of catheter tip at the temporoparietal area was associated with a significantly higher recurrence rate of CSDH than placement at the frontal area (p=0.006) and the brain re-expansion rate (BRR) was much lower than placement at the frontal area (p<0.001). CONCLUSION: The operation may be delayed in high- and mixed-density groups, unless severe symptoms or signs are present. In addition, placing the catheter tip at the frontal area helps to reduce the incidence of postoperative recurrence of CSDH and to increase the BRR.
Brain ; Butylated Hydroxytoluene ; Catheters ; Drainage ; Hematoma, Subdural, Chronic* ; Hemorrhage ; Humans ; Incidence ; Recurrence* ; Reoperation ; Retrospective Studies ; Risk Factors* ; Trephining*