Giving social support at work may reduce inflammation on employees themselves: a participatory workplace intervention study among Japanese hospital nurses.

Previously, we reported that the participatory workplace intervention was effective in reducing stress-related inflammatory markers among 31 Japanese female nurses. During the analysis, we recognized that our intervention might have increased prosocial behaviors like giving social support to others in some participants. Based on this assumption, we ran a secondary analysis, which examined the effect of giving social support on inflammatory markers, autonomic nervous activity (ANA), and perceived job stress (PJS) before and after the intervention. A group of participants who had increased scores on giving social support (n=13) showed significant decreases in interferon-γ, interleukin-6, and interleukin-12/23p40 after the intervention. Another group of those who had decreased/unchanged in the scores (n=17) did not show changes in these markers. Regarding ANA and PJS, no significant changes were observed in both groups. This study presented insight that giving social support at work may provide health benefits towards employees themselves, via decreasing inflammation.

Spontaneous pulmonary emphysema in mice lacking all three nitric oxide synthase isoforms.

The roles of endogenous nitric oxide (NO) derived from the entire NO synthases (NOSs) system have yet to be fully elucidated. We addressed this issue in mice in which all three NOS isoforms were deleted. Under basal conditions, the triple n/i/eNOSs-/- mice displayed significantly longer mean alveolar linear intercept length, increased alveolar destructive index, reduced lung elastic fiber content, lower lung field computed tomographic value, and greater end-expiratory lung volume as compared with wild-type (WT) mice. None of single NOS-/- or double NOSs-/- genotypes showed such features. These findings were observed in the triple n/i/eNOSs-/- mice as early as 4 weeks after birth. Cyclopaedic and quantitative comparisons of mRNA expression levels between the lungs of WT and triple n/i/eNOSs-/- mice by cap analysis of gene expression (CAGE) revealed that mRNA expression levels of three Wnt ligands and ten Wnt/ß-catenin signaling components were significantly reduced in the lungs of triple n/i/eNOSs-/- mice. These results provide the first direct evidence that complete disruption of all three NOS genes results in spontaneous pulmonary emphysema in juvenile mice in vivo possibly through down-regulation of the Wnt/ß-catenin signaling pathway, demonstrating a novel preventive role of the endogenous NO/NOS system in the occurrence of pulmonary emphysema.

Local Anesthetics Inhibit Transient Receptor Potential Vanilloid Subtype 3 Channel Function in Xenopus Oocytes.

BACKGROUND: The transient receptor potential vanilloid subtype 3 (TRPV3) channel is activated by innocuous temperature and several chemical stimuli. It is proposed to be involved in pathological pain development and is therefore considered a potential target for treating pain. Local anesthetics have been used for patients with both acute and chronic pain. Although blockage of the voltage-gated sodium channel is the primary mechanism by which local anesthetics exert their effects, they cannot be explained by this mechanism alone, especially in pathologic states such as chronic pain. Indeed, the effects of local anesthetics on multiple targets involved in the pain pathway have been reported. It has also been suggested that modulating the function of transient receptor potential (TRP) channels (eg, TRPV1 and transient receptor potential ankyrin 1 [TRPA1]) is one of the mechanisms of action of local anesthetics. However, the effects of local anesthetics on TRPV3 have not been reported. METHODS: We expressed TRPV3 in Xenopus oocytes and investigated the effects of local anesthetics on 2-aminoethoxydiphenyl borate (2APB)-induced currents using 2-electrode voltage-clamp techniques. RESULTS: Clinically used local anesthetics inhibited the 2APB-activated currents from the TRPV3 channel in a concentration-dependent manner at pharmacologically relevant concentrations with half maximal inhibitory concentration (IC50) values of 2.5 (lidocaine), 1.4 (mepivacaine), 0.28 (ropivacaine), and 0.17 (bupivacaine) mmol/L, respectively. Conversely, these local anesthetics also directly induced currents at higher concentrations, although these currents were quite small compared to the 2APB-induced currents. We found that the inhibition of TRPV3 by lidocaine is noncompetitive and independent of intracellular signaling cascades. 2APB-induced TRPV3 currents were reduced by extracellular N-(2,6-dimethylphenylcarbamoylmethyl) triethylammonium bromide (QX-314) but not by intracellular QX-314 nor benzocaine. Moreover, lidocaine showed a use-dependent block in TRPV3 inhibition. Finally, QX-314 appeared to slightly permeate the activated TRPV3 channel pore based on examination of oocytes coexpressing TRPV3 and a sodium channel. These results suggest that local anesthetics could inhibit TRPV3 channel function by extracellular interactions of their charged forms with the channel pore. CONCLUSIONS: Local anesthetics inhibited TRPV3 2APB-induced currents at pharmacologically relevant concentrations when TRPV3 was expressed in Xenopus oocytes. These effects seem to occur via an extracellular interaction between the charged form of the anesthetic with the TRPV3 channel pore. These results help to elucidate the mechanisms of action of local anesthetics.

Effects of participatory workplace improvement program on stress-related biomarkers and self-reported stress among university hospital nurses: a preliminary study.

Although participatory workplace improvement programs are known to provide favorable effects on high stress occupations like nursing, no studies have confirmed its effect using biomarkers. The aim of this study was to determine whether a participatory workplace improvement program would decrease stress-related symptoms as evaluated by biomarkers and self-reported stress among hospital nurses. Three actions to alleviate job stress, which were determined through focus group interviews and voting, were undertaken for two months. A total of 31 female Japanese nurses underwent measurement of inflammatory markers, autonomic nervous activity (ANA), and perceived job stress (PJS) at three-time points; before the program (T1), within a week after the completion of the program (T2), and three months after the program (T3). A series of inflammatory markers (Interferon-γ, Interleukin (IL)-6, and IL-12/23p40) decreased significantly at T2, and IL-12/23p40 and IL-15 significantly decreased at T3 compared to T1, while ANA and PJS remained unchanged. Our participatory program exerted beneficial effects in reducing inflammatory responses, but not for ANA and PJS. Further investigations with a better study design, i.e., a randomized controlled trial, and a larger sample size are warranted to determine what exerted beneficial effects on inflammatory markers and why other outcomes remained unchanged.

Carvacrol inhibits the neuronal voltage-gated sodium channels Nav1.2, Nav1.6, Nav1.3, Nav1.7, and Nav1.8 expressed in Xenopus oocytes with different potencies.

Carvacrol is the predominant monoterpene in essential oils from many aromatic plants. Several animal studies showing analgesic effects of carvacrol indicate potential of carvacrol as a new medication for patients with refractory pain. Voltage-gated sodium channels (Nav) are thought to have crucial roles in the development of inflammatory and neuropathic pain, but there is limited information about whether the analgesic mechanism of carvacrol involves Nav. We used whole-cell, two-electrode, voltage-clamp techniques to examine the effects of carvacrol on sodium currents in Xenopus oocytes expressing α subunits of Nav1.2, Nav1.3, Nav1.6, Nav1.7, and Nav1.8. Carvacrol dose-dependently suppressed sodium currents at a holding potential that induced half-maximal current. The half-maximal inhibitory concentration values for Nav1.2, Nav1.3, Nav1.6, Nav1.7, and Nav1.8 were 233, 526, 215, 367, and 824 µmol/L, respectively, indicating that carvacrol had more potent inhibitory effects towards Nav1.2 and Nav1.6 than Nav1.3, Nav1.7, and Nav1.8. Gating analysis showed a depolarizing shift of the activation curve and a hyperpolarizing shift of the inactivation curve in all five α subunits following carvacrol treatment. Furthermore, carvacrol exhibits a use-dependent block for all five α Nav subunits. These findings provide a better understanding of the mechanisms associated with the analgesic effect of carvacrol.

The neurosteroid allopregnanolone sulfate inhibits Nav1.3 α subunit-containing voltage-gated sodium channels, expressed in Xenopus oocytes.

The neurosteroid allopregnanolone has potent analgesic effects, and its potential use for neuropathic pain is supported by recent reports. However, the analgesic mechanisms are obscure. The voltage-gated sodium channels (Nav) α subunit Nav1.3 is thought to play an essential role in neuropathic pain. Here, we report the effects of allopregnanolone sulfate (APAS) on sodium currents (INa) in Xenopus oocytes expressing Nav1.3 with ß1 or ß3 subunits. APAS suppressed INa of Nav1.3 with ß1 and ß3 in a concentration-dependent manner (IC50 values; 75 and 26 µmol/L). These results suggest the possible importance of Nav1.3 inhibition for the analgesic mechanisms of allopregnanolone.

Angiotensin II promotes pulmonary metastasis of melanoma through the activation of adhesion molecules in vascular endothelial cells.

Hypertension is considered as one of the cancer progressive factors, and often found comorbidity in cancer patients. Renin-angiotensin system (RAS) plays an important role in the regulation of blood pressure, and angiotensin II (Ang II) is well known pressor peptide associated with RAS. Ang II has been reported to accelerate progression and metastasis of cancer cells. However, its precise mechanisms have not been fully understood. In this study, we sought to elucidate the mechanisms by which Ang II exacerbates hematogenous metastasis in mouse melanoma cells, focusing the adhesion pathway in vascular endothelial cells. For this purpose, B16/F10 mouse melanoma cells, which do not express the Ang II type 1 receptor (AT1R), were intravenously injected into C57BL/6 mice. Two weeks after cell injection, the number of lung metastatic colonies was significantly higher in the Ang II-treated group (1 µg/kg/min) than in the vehicle-treated group. The AT1R blocker valsartan (40 mg/kg/day), but not the calcium channel blocker amlodipine (5 or 10 mg/kg/day), significantly suppressed the effect of Ang II. In endothelium-specific Agtr1a knockout mice, Ang II-mediated acceleration of lung metastases of melanoma cells was significantly diminished. Ang II treatment significantly increased E-selectin mRNA expression in vascular endothelial cells collected from lung tissues, and thus promoted adherence of melanoma cells to the vascular endothelium. Ang II-accelerated lung metastases of melanoma cells were also suppressed by treatment with anti-E-selectin antibody (20 mg/kg). Taken together, Ang II-treatment exacerbates hematogenous cancer metastasis by promoting E-selectin-mediated adhesion of cancer cells to vascular endothelial cells.

Protective Role of Myelocytic Nitric Oxide Synthases against Hypoxic Pulmonary Hypertension in Mice.

RATIONALE: Nitric oxide (NO), synthesized by NOSs (NO synthases), plays a role in the development of pulmonary hypertension (PH). However, the role of NO/NOSs in bone marrow (BM) cells in PH remains elusive. OBJECTIVES: To determine the role of NOSs in BM cells in PH. METHODS: Experiments were performed on 36 patients with idiopathic pulmonary fibrosis and on wild-type (WT), nNOS (neuronal NOS)-/-, iNOS (inducible NOS)-/-, eNOS (endothelial NOS)-/-, and n/i/eNOSs-/- mice. MEASUREMENTS AND MAIN RESULTS: In the patients, there was a significant correlation between higher pulmonary artery systolic pressure and lower nitrite plus nitrate levels in the BAL fluid. In the mice, hypoxia-induced PH deteriorated significantly in the n/i/eNOSs-/- genotype and, to a lesser extent, in the eNOS-/- genotype as compared with the WT genotype. In the n/i/eNOSs-/- genotype exposed to hypoxia, the number of circulating BM-derived vascular smooth muscle progenitor cells was significantly larger, and transplantation of green fluorescent protein-transgenic BM cells revealed the contribution of BM cells to pulmonary vascular remodeling. Importantly, n/i/eNOSs-/--BM transplantation significantly aggravated hypoxia-induced PH in the WT genotype, and WT-BM transplantation significantly ameliorated hypoxia-induced PH in the n/i/eNOSs-/- genotype. A total of 69 and 49 mRNAs related to immunity and inflammation, respectively, were significantly upregulated in the lungs of WT genotype mice transplanted with n/i/eNOSs-/--BM compared with those with WT-BM, suggesting the involvement of immune and inflammatory mechanisms in the exacerbation of hypoxia-induced PH caused by n/i/eNOSs-/--BM transplantation. CONCLUSIONS: These results demonstrate that myelocytic n/i/eNOSs play an important protective role in the pathogenesis of PH.

Antidepressants inhibit Nav1.3, Nav1.7, and Nav1.8 neuronal voltage-gated sodium channels more potently than Nav1.2 and Nav1.6 channels expressed in Xenopus oocytes.

Tricyclic antidepressants (TCAs) and duloxetine are used to treat neuropathic pain. However, the mechanisms underlying their analgesic effects remain unclear. Although many investigators have shown inhibitory effects of antidepressants on voltage-gated sodium channels (Nav) as a possible mechanism of analgesia, to our knowledge, no one has compared effects on the diverse variety of sodium channel α subunits. We investigated the effects of antidepressants on sodium currents in Xenopus oocytes expressing Nav1.2, Nav1.3, Nav1.6, Nav1.7, and Nav1.8 with a ß1 subunit by using whole-cell, two-electrode, voltage clamp techniques. We also studied the role of the ß3 subunit on the effect of antidepressants on Nav1.3. All antidepressants inhibited sodium currents in an inactivated state induced by all five α subunits with ß1. The inhibitory effects were more potent for Nav1.3, Nav1.7, and Nav1.8, which are distributed in dorsal root ganglia, than Nav1.2 and Nav1.6, which are distributed primarily in the central nervous system. The effect of amitriptyline on Nav1.7 with ß1 was most potent with a half-maximal inhibitory concentration (IC50) 4.6 µmol/L. IC50 for amitriptyline on Nav1.3 coexpressed with ß1 was lowered from 8.4 to 4.5 µmol/L by coexpression with ß3. Antidepressants predominantly inhibited the sodium channels expressed in dorsal root ganglia, and amitriptyline has the most potent inhibitory effect. This is the first evidence, to our knowledge, showing the diverse effects of antidepressants on various α subunits. Moreover, the ß3 subunit appears important for inhibition of Nav1.3. These findings may aid better understanding of the mechanisms underlying the pain relieving effects of antidepressants.

Inhibitory effects of pine nodule extract and its component, SJ-2, on acetylcholine-induced catecholamine secretion and synthesis in bovine adrenal medullary cells.

Extract of pine nodules (matsufushi) formed by bark proliferation on the surface of trees of Pinus tabulaeformis or Pinus massoniana has been used as an analgesic for joint pain, rheumatism, neuralgia, dysmenorrhea and other complaints in Chinese traditional medicine. Here we report the effects of matsufushi extract and its components on catecholamine secretion and synthesis in cultured bovine adrenal medullary cells. We found that matsufushi extract (0.0003-0.005%) and its component, SJ-2 (5-hydroxy-3-methoxy-trans-stilbene) (0.3-100 µM), but not the other three, concentration-dependently inhibited catecholamine secretion induced by acetylcholine, a physiological secretagogue. Matsufushi extract (0.0003-0.005%) and SJ-2 (0.3-100 µM) also inhibited 45Ca2+ influx induced by acetylcholine in a concentration-dependent manner, similar to its effect on catecholamine secretion. They also suppressed 14C-catecholamine synthesis and tyrosine hydroxylase activity induced by acetylcholine. In Xenopus oocytes expressing α3ß4 nicotinic acetylcholine receptors, matsufushi extract (0.00003-0.001%) and SJ-2 (1-100 µM) directly inhibited the current evoked by acetylcholine. The present findings suggest that SJ-2, as well as matsufushi extract, inhibits acetylcholine-induced catecholamine secretion and synthesis by suppression of nicotinic acetylcholine receptor-ion channels in bovine adrenal medullary cells.

Long-term dietary nitrite and nitrate deficiency causes the metabolic syndrome, endothelial dysfunction and cardiovascular death in mice.

AIMS/HYPOTHESIS: Nitric oxide (NO) is synthesised not only from L-arginine by NO synthases (NOSs), but also from its inert metabolites, nitrite and nitrate. Green leafy vegetables are abundant in nitrate, but whether or not a deficiency in dietary nitrite/nitrate spontaneously causes disease remains to be clarified. In this study, we tested our hypothesis that long-term dietary nitrite/nitrate deficiency would induce the metabolic syndrome in mice. METHODS: To this end, we prepared a low-nitrite/nitrate diet (LND) consisting of an amino acid-based low-nitrite/nitrate chow, in which the contents of L-arginine, fat, carbohydrates, protein and energy were identical with a regular chow, and potable ultrapure water. Nitrite and nitrate were undetectable in both the chow and the water. RESULTS: Three months of the LND did not affect food or water intake in wild-type C57BL/6J mice compared with a regular diet (RD). However, in comparison with the RD, 3 months of the LND significantly elicited visceral adiposity, dyslipidaemia and glucose intolerance. Eighteen months of the LND significantly provoked increased body weight, hypertension, insulin resistance and impaired endothelium-dependent relaxations to acetylcholine, while 22 months of the LND significantly led to death mainly due to cardiovascular disease, including acute myocardial infarction. These abnormalities were reversed by simultaneous treatment with sodium nitrate, and were significantly associated with endothelial NOS downregulation, adiponectin insufficiency and dysbiosis of the gut microbiota. CONCLUSIONS/INTERPRETATION: These results provide the first evidence that long-term dietary nitrite/nitrate deficiency gives rise to the metabolic syndrome, endothelial dysfunction and cardiovascular death in mice, indicating a novel pathogenetic role of the exogenous NO production system in the metabolic syndrome and its vascular complications.

Decreased Bronchial Eosinophilic Inflammation and Mucus Hypersecretion in Asthmatic Mice Lacking All Nitric Oxide Synthase Isoforms.

BACKGROUND: Asthma is characterized by airflow limitation with chronic airway inflammation, hyperresponsiveness and mucus hypersecretion. NO is generated by three nitric oxide synthase (i/n/eNOSs) isoforms, but conflicting results have been reported using asthmatic mice treated with NOSs inhibitors and NOS-knockout mice. To elucidate the authentic role of NO/NOSs in asthma, we used asthmatic mice lacking all NOSs (n/i/eNOS(-/-)). METHODS: Wild-type and n/i/eNOS(-/-) mice were sensitized and challenged with ovalbumin. Pathological findings and expressions of interferon (IFN)-γ, interleukin (IL)-4, -5, -10, -13 and chemokines in the lung were evaluated. RESULTS: Decreased eosinophilic inflammation, bronchial thickening and mucus secretion, IL-4, -5 and -13, monocyte chemoattractant protein-1, eotaxin-1 and thymus and activation-regulated chemokine expressions were observed in n/i/eNOS(-/-) mice compared to wild-type, but expressions of IFN-γ and IL-10 were similar. CONCLUSION: Using asthmatic n/i/eNOS(-/-) mice, NO plays important roles in accelerating bronchial eosinophilic inflammation and mucus hypersecretion in the pathophysiology of asthma.

Ikarisoside A inhibits acetylcholine-induced catecholamine secretion and synthesis by suppressing nicotinic acetylcholine receptor-ion channels in cultured bovine adrenal medullary cells.

Ikarisoside A is a natural flavonol glycoside derived from plants of the genus Epimedium, which have been used in Traditional Chinese Medicine as tonics, antirheumatics, and aphrodisiacs. Here, we report the effects of ikarisoside A and three other flavonol glycosides on catecholamine secretion and synthesis in cultured bovine adrenal medullary cells. We found that ikarisoside A (1-100 µM), but not icariin, epimedin C, or epimedoside A, concentration-dependently inhibited the secretion of catecholamines induced by acetylcholine, a physiological secretagogue and agonist of nicotinic acetylcholine receptors. Ikarisoside A had little effect on catecholamine secretion induced by veratridine and 56 mM K(+). Ikarisoside A (1-100 µM) also inhibited (22)Na(+) influx and (45)Ca(2+) influx induced by acetylcholine in a concentration-dependent manner similar to that of catecholamine secretion. In Xenopus oocytes expressing α3ß4 nicotinic acetylcholine receptors, ikarisoside A (0.1-100 µM) directly inhibited the current evoked by acetylcholine. It also suppressed (14)C-catecholamine synthesis and tyrosine hydroxylase activity induced by acetylcholine at 1-100 µM and 10-100 µM, respectively. The present findings suggest that ikarisoside A inhibits acetylcholine-induced catecholamine secretion and synthesis by suppression of nicotinic acetylcholine receptor-ion channels in bovine adrenal medullary cells.

Effects of various pharmacological agents on the function of norepinephrine transporter.

The norepinephrine transporter is selectively expressed in noradrenergic nerve terminals, where it can exert spatial and temporal control over the action of norepinephrine. The norepinephrine transporter mediates the termination of neurotransmission via the reuptake of norepinephrine released into the extracellular milieu. In the present brief review, we report our recent studies about the effects of various pharmacological agents such as fasudil, nicotine, pentazocine, ketamine and genistein on norepinephrine transporter function.

Lidocaine preferentially inhibits the function of purinergic P2X7 receptors expressed in Xenopus oocytes.

BACKGROUND: Lidocaine has been widely used to relieve acute pain and chronic refractory pain effectively by both systemic and local administration. Numerous studies reported that lidocaine affects several pain signaling pathways as well as voltage-gated sodium channels, suggesting the existence of multiple mechanisms underlying pain relief by lidocaine. Some extracellular adenosine triphosphate (ATP) receptor subunits are thought to play a role in chronic pain mechanisms, but there have been few studies on the effects of lidocaine on ATP receptors. We studied the effects of lidocaine on purinergic P2X3, P2X4, and P2X7 receptors to explore the mechanisms underlying pain-relieving effects of lidocaine. METHODS: We investigated the effects of lidocaine on ATP-induced currents in ATP receptor subunits, P2X3, P2X4, and P2X7 expressed in Xenopus oocytes, by using whole-cell, two-electrode, voltage-clamp techniques. RESULTS: Lidocaine inhibited ATP-induced currents in P2X7, but not in P2X3 or P2X4 subunits, in a concentration-dependent manner. The half maximal inhibitory concentration for lidocaine inhibition was 282 ± 45 µmol/L. By contrast, mepivacaine, ropivacaine, and bupivacaine exerted only limited effects on the P2X7 receptor. Lidocaine inhibited the ATP concentration-response curve for the P2X7 receptor via noncompetitive inhibition. Intracellular and extracellular N-(2,6-dimethylphenylcarbamoylmethyl) triethylammonium bromide (QX-314) and benzocaine suppressed ATP-induced currents in the P2X7 receptor in a concentration-dependent manner. In addition, repetitive ATP treatments at 5-minute intervals in the continuous presence of lidocaine revealed that lidocaine inhibition was use-dependent. Finally, the selective P2X7 receptor antagonists Brilliant Blue G and AZ11645373 did not affect the inhibitory actions of lidocaine on the P2X7 receptor. CONCLUSIONS: Lidocaine selectively inhibited the function of the P2X7 receptor expressed in Xenopus oocytes. This effect may be caused by acting on sites in the ion channel pore both extracellularly and intracellularly. These results help to understand the mechanisms underlying the analgesic effects of lidocaine when it is administered locally at least.

Significance of nitric oxide synthases: Lessons from triple nitric oxide synthases null mice.

Nitric oxide (NO) is synthesized by three distinct NO synthases (neuronal, inducible, and endothelial NOSs), all of which are expressed in almost all tissues and organs in humans. The regulatory roles of NOSs in vivo have been investigated in pharmacological studies with non-selective NOS inhibitors. However, the specificity of the inhibitors continues to be an issue of debate, and the authentic significance of NOSs is still poorly understood. To address this issue, we generated mice in which all three NOS genes are completely disrupted. The triple NOSs null mice exhibited cardiovascular abnormalities, including hypertension, arteriosclerosis, myocardial infarction, cardiac hypertrophy, diastolic heart failure, and reduced EDHF responses, with a shorter survival. The triple NOSs null mice also displayed metabolic abnormalities, including metabolic syndrome and high-fat diet-induced severe dyslipidemia. Furthermore, the triple NOSs null mice showed renal abnormalities (nephrogenic diabetes insipidus and pathological renal remodeling), lung abnormalities (accelerated pulmonary fibrosis), and bone abnormalities (increased bone mineral density and bone turnover). These results provide evidence that NOSs play pivotal roles in the pathogenesis of a wide variety of disorders. This review summarizes the latest knowledge on the significance of NOSs in vivo, based on lessons learned from experiments with our triple mutant model.

[Application of power spectral analysis of heart rate variability to women with climacteric symptoms].

Climacteric symptoms are multiple syndromes in menopausal women. It is known that autonomic nervous activity disorder plays an important role in these symptoms. In the present brief review, we report our recent studies of the relation between climacteric symptoms and autonomic nervous system balance measured by power spectral analysis of heart rate variability (HRV) using a standard hexagon radar chart. The sympathetic excitability and irritability, and the standard deviation of mean R-R intervals in the supine position were significantly decreased in women with climacteric symptoms compared to control women without climacteric symptoms. There was a negative correlation (r = -0.363, P = 0.0167) between the standard deviation of mean R-R intervals in the supine position and the simplified menopausal index score. These results show suggest a close relation between climacteric symptoms and autonomic nervous activities, and our power spectral analysis of HRV, which provides a standard hexagonal radar chart composed of three sympathetic and three parasympathetic parameters, may be helpful in the diagnosis and treatment of climacteric symptoms in menopausal women.

Development of an experimentally useful model of acute myocardial infarction: 2/3 nephrectomized triple nitric oxide synthases-deficient mouse.

We investigated the effect of subtotal nephrectomy on the incidence of acute myocardial infarction (AMI) in mice deficient in all three nitric oxide synthases (NOSs). Two-thirds nephrectomy (NX) was performed on male triple NOSs(-/-) mice. The 2/3NX caused sudden cardiac death due to AMI in the triple NOSs(-/-) mice as early as 4months after the surgery. The 2/3NX triple NOSs(-/-) mice exhibited electrocardiographic ST-segment elevation, reduced heart rate variability, echocardiographic regional wall motion abnormality, and accelerated coronary arteriosclerotic lesion formation. Cardiovascular risk factors (hypertension, hypercholesterolemia, and hyperglycemia), an increased number of circulating bone marrow-derived vascular smooth muscle cell (VSMC) progenitor cells (a pro-arteriosclerotic factor), and cardiac up-regulation of stromal cell-derived factor (SDF)-1α (a chemotactic factor of the progenitor cells) were noted in the 2/3NX triple NOSs(-/-) mice and were associated with significant increases in plasma angiotensin II levels (a marker of renin-angiotensin system activation) and urinary 8-isoprostane levels (a marker of oxidative stress). Importantly, combined treatment with a clinical dosage of an angiotensin II type 1 receptor blocker, irbesartan, and a calcium channel antagonist, amlodipine, markedly prevented coronary arteriosclerotic lesion formation and the incidence of AMI and improved the prognosis of those mice, along with ameliorating all those pro-arteriosclerotic parameters. The 2/3NX triple NOSs(-/-) mouse is a new experimentally useful model of AMI. Renin-angiotensin system activation, oxidative stress, cardiovascular risk factors, and SDF-1α-induced recruitment of bone marrow-derived VSMC progenitor cells appear to be involved in the pathogenesis of AMI in this model.

Nitric oxide exerts protective effects against bleomycin-induced pulmonary fibrosis in mice.

BACKGROUND: Increased expression of nitric oxide synthase (NOS) and an increase in plasma nitrite plus nitrate (NOx) have been reported in patients with pulmonary fibrosis, suggesting that nitric oxide (NO) plays an important role in its development. However, the roles of the entire NO and NOS system in the pathogenesis of pulmonary fibrosis still remain to be fully elucidated. The aim of the present study is to clarify the roles of NO and the NOS system in pulmonary fibrosis by using the mice lacking all three NOS isoforms. METHODS: Wild-type, single NOS knockout and triple NOS knockout (n/i/eNOS-/-) mice were administered bleomycin (BLM) intraperitoneally at a dose of 8.0 mg/kg/day for 10 consecutive days. Two weeks after the end of the procedure, the fibrotic and inflammatory changes of the lung were evaluated. In addition, we evaluated the effects of long-term treatment with isosorbide dinitrate, a NO donor, on the n/i/eNOS-/- mice with BLM-induced pulmonary fibrosis. RESULTS: The histopathological findings, collagen content and the total cell number in bronchoalveolar lavage fluid were the most severe/highest in the n/i/eNOS-/- mice. Long-term treatment with the supplemental NO donor in n/i/eNOS-/- mice significantly prevented the progression of the histopathological findings and the increase of the collagen content in the lungs. CONCLUSIONS: These results provide the first direct evidence that a lack of all three NOS isoforms led to a deterioration of pulmonary fibrosis in a BLM-treated murine model. We speculate that the entire endogenous NO and NOS system plays an important protective role in the pathogenesis of pulmonary fibrosis.

Neurosteroids allopregnanolone sulfate and pregnanolone sulfate have diverse effect on the α subunit of the neuronal voltage-gated sodium channels Nav1.2, Nav1.6, Nav1.7, and Nav1.8 expressed in xenopus oocytes.

BACKGROUND: The neurosteroids allopregnanolone and pregnanolone are potent positive modulators of γ-aminobutyric acid type A receptors. Antinociceptive effects of allopregnanolone have attracted much attention because recent reports have indicated the potential of allopregnanolone as a therapeutic agent for refractory pain. However, the analgesic mechanisms of allopregnanolone are still unclear. Voltage-gated sodium channels (Nav) are thought to play important roles in inflammatory and neuropathic pain, but there have been few investigations on the effects of allopregnanolone on sodium channels. METHODS: Using voltage-clamp techniques, the effects of allopregnanolone sulfate (APAS) and pregnanolone sulfate (PAS) on sodium current were examined in Xenopus oocytes expressing Nav1.2, Nav1.6, Nav1.7, and Nav1.8 α subunits. RESULTS: APAS suppressed sodium currents of Nav1.2, Nav1.6, and Nav1.7 at a holding potential causing half-maximal current in a concentration-dependent manner, whereas it markedly enhanced sodium current of Nav1.8 at a holding potential causing maximal current. Half-maximal inhibitory concentration values for Nav1.2, Nav1.6, and Nav1.7 were 12 ± 4 (n = 6), 41 ± 2 (n = 7), and 131 ± 15 (n = 5) µmol/l (mean ± SEM), respectively. The effects of PAS were lower than those of APAS. From gating analysis, two compounds increased inactivation of all α subunits, while they showed different actions on activation of each α subunit. Moreover, two compounds showed a use-dependent block on Nav1.2, Nav1.6, and Nav1.7. CONCLUSION: APAS and PAS have diverse effects on sodium currents in oocytes expressing four α subunits. APAS inhibited the sodium currents of Nav1.2 most strongly.