Difference in Contractile Mechanisms between the Early and Sustained Components of Ionomycin-Induced Contraction in Rat Caudal Arterial Smooth Muscle.

We previously reported that the sustained component of contraction induced by depolarizing stimulation by high K+ concentration in rat caudal arterial smooth muscle involves a Ca2+-induced Ca2+ sensitization mechanism whereby Ca2+ entry through voltage-gated Ca2+ channels activates proline-rich tyrosine kinase 2 (Pyk2), leading to activation of RhoA/Rho-associated kinase (ROCK). In the present study, we investigated a potential role for Pyk2-mediated RhoA/ROCK activation in contraction mediated by elevation of cytosolic free Ca2+ concentration ([Ca2+]i) induced by a Ca2+ ionophore, ionomycin, rather than by depolarizing stimulation. Ionomycin (60 µM) induced slow and sustained contraction of rat caudal arterial smooth muscle due to influx of Ca2+. Pre-treatment with a myosin light chain kinase (MLCK) inhibitor, ML-9 (30 µM), inhibited both the early phase (4 min) and the sustained phase (30 min) of ionomycin-induced contraction. On the other hand, a ROCK inhibitor, HA-1077 (3 µM), and Pyk2 inhibitors, sodium salicylate (10 mM) and PF-431396 (3 µM), suppressed only the sustained phase of ionomycin-induced contraction. A calmodulin (CaM) inhibitor, W-7 (150 µM), but not W-5 (150 µM), suppressed the early phase of contraction. Early or sustained increase of ionomycin-induced 20 kDa light chain of myosin (LC20) phosphorylation was inhibited by each inhibitor in a manner similar to the attenuation of contraction. These results indicate that the early phase of ionomycin-induced contraction is mediated by MLCK activation by [Ca2+]i elevation, whereas the sustained phase of ionomycin-induced contraction involves RhoA/ROCK activation and inhibition of myosin light chain phosphatase (MLCP) through CaM-independent Pyk2 activation by [Ca2+]i elevation.

[Investigation into the Effect of Shitei Extract, a Traditional Chinese Medicine Formulation, on Hiccups].

Hiccups are occasionally experienced by most individuals, and although not life-threatening, they may leadto a decline in quality of life. Shitei extract(shitei, persimmon calyx)may be usedfor the treatment of hiccups. The effects of shitei extract were investigatedin patients admittedto the Japanese RedCross Musashino Hospital between October 2011 andM ay 2016. Numerous prescriptions for shitei extract were reportedin the Department of Respiratory Organs andNeurosurgery. The primary causes of hiccups were chemotherapy andbrain disease. Of 149 patients, 107(71.8%)sufferedfrom hiccups. None of the patients reported adverse events related to the administration of shitei extract. The incidence of hiccups was significantly higher in patients with brain disease(p=0.0075), treatedwith chemotherapy for cancer(p=0.0402), or requiring the insertion of a gastric tube(p=0.0065). Among those treatedwith chemotherapy for cancer, shitei extract was effective against hiccups in 82.0% patients(45 of 55). Furthermore, four patients receivedprophylaxis with shitei extract for the prevention of hiccups after chemotherapy. In conclusion, these results indicate that shitei extract is an effective and safe therapeutic drug for the treatment of hiccups. In particular, shitei extract was effective in the prevention of hiccups after chemotherapy.

The Association between Molecular Initiating Events and Drug-Induced Hiccups.

Hiccups can significantly reduce the quality of life of patients and can occur as a drug side effect. Previous reports have revealed sex-specific differences in the incidence of drug-induced hiccups. However, the pathogenesis of drug-induced hiccups remains unknown, and there is limited evidence on its treatment or prevention. This study examined molecular initiating events (MIEs), which are the starting point of adverse events, to investigate the drug-induced pathways of hiccups. We extracted drugs suspected to cause hiccups using the FDA Adverse Event Reporting System, a large database on adverse drug reactions. Information on drugs suspected to be associated with hiccups was extracted from the overall population and sex-specific subgroups were divided. In each data table, the predicted activity values of nuclear receptors and stress response pathways for each drug were calculated using the Toxicity Predictor, a machine-learning model. Transforming growth factor-beta and antioxidant response elements were considered an independent factor for hiccups in the male and female subgroups, respectively. This report first examined one of the mechanisms of drug-induced hiccups and identified MIEs associated with drug-induced hiccups. The use of an adverse event database and the machine-learning model, Toxicity Predictor, may be useful for generating hypotheses for other adverse effects with unknown mechanisms.

Niflumic acid activates additional currents of the human glial L-glutamate transporter EAAT1 in a substrate-dependent manner.

The astrocytic L-glutamate (L-Glu) transporter EAAT1 participates in the removal of L-Glu from the synaptic cleft and maintenance of non-toxic concentrations in the extracellular fluid. We have shown that niflumic acid (NFA), a non-steroidal anti-inflammatory drug (NSAIDs), alters L-Glu-induced EAAT1 currents in a voltage-dependent manner using the two-electrode voltage clamp technique in Xenopus oocytes expressing EAAT1. In this study, we characterised the effects of NFA on each type of ion-flux through EAAT1. NFA modulated currents induced by both L-Glu and L-aspartate (L-Asp) in a voltage-dependent manner. Ion-substitution experiments revealed that the activation of additional H(+) conductance was involved in the modulation of currents induced by L-Asp and L-Glu, but Cl(-) was involved only with the L-Asp currents. NFA activated additional currents of EAAT1 in a substrate-dependent manner.

Dysfunction of neurotransmitter modulation system on adrenergic nerves of caudal artery in type 2 diabetic Goto-Kakizaki rats.

The Goto-Kakizaki (GK) rat is a non-obese and spontaneous model of mild Type 2 diabetes mellitus. In the present study, we compared the regulatory mechanisms of endogenous norepinephrine (NE) release from sympathetic nerves of caudal arteries of 12-week-old GK rats and age-matched normal Wistar rats. Electrical stimulation (ES) evoked significant NE release from caudal arteries of Wistar and GK rats. The amounts of NE released by ES were almost equal in Wistar and GK rats, although the NE content in caudal artery of GK rats was significantly lower than that of Wistar rats. We examined the effects of an α2-adrenoceptor agonist, clonidine (CLO), and an α2-adrenoceptor antagonist, yohimbine (YOH), on the release of endogenous NE evoked by ES. CLO significantly reduced NE release from caudal arteries of Wistar but not GK rats. On the other hand, YOH significantly increased NE release from both rats. Furthermore, we examined the effects of an A1-adenosine receptor agonist, 2-chloroadenosine (2CA), and an A1-adenosine receptor antagonist, 8-sulfophenyltheophylline (8SPT), on the release of endogenous NE evoked by ES. 2CA significantly reduced NE release from caudal arteries of Wistar but not GK rats. On the other hand, 8SPT did not affect NE release from both rats. These results suggest that the dysfunction of negative feedback regulation of NE release via presynaptic receptors on sympathetic nerves in GK rats may be involved in the autonomic nervous system dysfunction associated with diabetic autonomic neuropathy.

Analysis of Factors Associated with Hiccups Using the FAERS Database.

In this study, we used the large number of cases in the FDA adverse-event reporting system (FAERS) database to investigate risk factors for drug-induced hiccups and to explore the relationship between hiccups and gender. From 11,810,863 adverse drug reactions reported between the first quarter of 2004 and the first quarter of 2020, we extracted only those in which side effects occurred between the beginning and end of drug administration. Our sample included 1454 adverse reactions for hiccups, with 1159 involving males and 257 involving females (the gender in 38 reports was unknown). We performed univariate analyses of the presence or absence of hiccups for each drug and performed multivariate analysis by adding patient information. The multivariate analysis showed nicotine products to be key suspect drugs for both men and women. For males, the risk factors for hiccups included older age, lower body weight, nicotine, and 14 other drugs. For females, only nicotine and three other drugs were extracted as independent risk factors. Using FAERS, we were thus able to extract new suspect drugs for drug-induced hiccups. Furthermore, this is the first report of a gender-specific analysis of risk factors for hiccups that provides novel insights into drug-induced hiccups, and it suggests that the mechanism responsible is strongly related to gender. Thus, this study can contribute to elucidating the mechanism underlying this phenomenon.

Two non-steroidal anti-inflammatory drugs, niflumic acid and diclofenac, inhibit the human glutamate transporter EAAT1 through different mechanisms.

We investigated the effects of non-steroidal anti-inflammatory drugs on substrate-induced currents of L-glutamate (L-Glu) transporter EAAT1 expressed in Xenopus laevis oocytes. Niflumic acid (NFA) and diclofenac inhibited L-Glu-induced current through EAAT1 in a non-competitive manner. NFA produced a leftward shift in reversal potential (E(rev)) of L-Glu-induced current and increased current amplitude at the potentials more negative than -100 mV. Diclofenac had no effects on E(rev) and inhibited the current amplitude to the same extent at all negative potentials. These results indicate that NFA and diclofenac inhibit the L-Glu-induced EAAT1 current via different mechanisms.

Effect of chondroitinase on dermatan sulfate-facilitated arginine amidase released from rabbit ear artery.

We examined the effects of chondroitinases on the release of dermatan sulfate (DS)-induced arginine amidase (AA) from rabbit ear artery. DS-induced AA release was significantly decreased by treatment with chondroitinase ABC (ABCase) in the rabbit ear artery. On the other hand, Chondroitinase ACII (ACIIase) enhanced spontaneous and DS-induced AA release. Heat-inactivated ABCase and ACIIase did not affect spontaneous and DS-induced AA release. Furthermore, ABCase, but not ACIIase and heat-inactivated chondroitinases, degraded DS. These results indicate that the facilitatory effect of DS-induced AA release from the rabbit ear artery is affected by the molecular size of DS.

[Examination of questionnaires regarding diabetic peripheral neuropathy in epalrestat-treated patients and their usefulness in the treatment of the patients during the treatment course].

Epalrestat (Kinedak) is an aldose reductase inhibitor (ARI) for diabetic peripheral neuropathy. In 41 diabetics, we conducted a questionnaire survey to evaluate symptoms of peripheral neuropathy and select appropriate drug therapy. We investigated 27 patients who participated in the first and second questionnaire surveys. We reviewed questionnaire items, and examined the correlation between the therapeutic effects and responses to the questionnaire. Concerning the usefulness of the questionnaire items, some questions were correlated with the effects. Treatment was effective for somatic neuropathy, but not for autonomic neuropathy. The questionnaire regarding diabetic peripheral neuropathy was useful for somatic neuropathy screening, but it was difficult to detect autonomic neuropathy.

[Survey of the drugs remaining in the diskhaler and investigation of cleaning of fluticasone propionate].

When a fluticasone propionate (FP) diskhaler is used to administer inhaled corticosteroid, it has been reported that there is considerable drug residue remaining in the diskhaler after use. The internal structure of the diskhaler is complex, and it is possible that sufficient cleaning of the device is not achieved using the attached brush. In this study, the diskhaler cleaning method was examined using a patient questionnaire. In response to the question on cleaning, 56.3% of patients responded "Having done", and 66.7% responded to the question on the frequency of the cleaning, "When I use it". Furthermore, cleaning by a healthy volunteer was examined using Rotadisk for inhalation practice. When the group that did not perform cleaning was compared with the group that performed cleaning with the brush, the amount of the lactose adhesion was significantly lower in the cleaning group. When the no-cleaning group was compared with the group that shook off the excess residue from the tray and the main body of the diskhaler, the group that shook off the diskhaler components showed a significantly lower amount of lactose adhesion. It was confirmed that drug residue were able to accumulate, and the shaking off method appeared to have an effect equal to that of cleaning with the brush. It seems that providing patients with guidance not only about the method of inhaling with the diskhaler but also about cleaning of the device is an important area of pharmacy patient management.

Analysis of factors associated with hiccups based on the Japanese Adverse Drug Event Report database.

Hiccups are occasionally experienced by most individuals. Although hiccups are not life-threatening, they may lead to a decline in quality of life. Previous studies showed that hiccups may occur as an adverse effect of certain medicines during chemotherapy. Furthermore, a male dominance in hiccups has been reported. However, due to the limited number of studies conducted on this phenomenon, debate still surrounds the few factors influencing hiccups. The present study aimed to investigate the influence of medicines and patient characteristics on hiccups using a large-sized adverse drug event report database and, specifically, the Japanese Adverse Drug Event Report (JADER) database. Cases of adverse effects associated with medications were extracted from JADER, and Fisher's exact test was performed to assess the presence or absence of hiccups for each medication. In a multivariate analysis, we conducted a multiple logistic regression analysis using medication and patient characteristic variables exhibiting significance. We also examined the role of dexamethasone in inducing hiccups during chemotherapy. Medicines associated with hiccups included dexamethasone, levofolinate, fluorouracil, oxaliplatin, carboplatin, and irinotecan. Patient characteristics associated with hiccups included a male gender and greater height. The combination of anti-cancer agent and dexamethasone use was noted in more than 95% of patients in the dexamethasone-use group. Hiccups also occurred in patients in the anti-cancer agent-use group who did not use dexamethasone. Most of the medications that induce hiccups are used in chemotherapy. The results of the present study suggest that it is possible to predict a high risk of hiccups using patient characteristics. We confirmed that dexamethasone was the drug that has the strongest influence on the induction of hiccups. However, the influence of anti-cancer agents on the induction of hiccups cannot be denied. We consider the results of the present study to be helpful for the prevention and treatment of hiccups.

Inhibition of Ectopic Arginine Vasopressin Production by Phenytoin in the Small Cell Lung Cancer Cell Line Lu-165.

Phenytoin, a voltage-gated sodium channel (NaV channel) antagonist, reportedly inhibits arginine vasopressin (AVP) release from an isolated rat neurohypophysis. So far, it is uncertain whether phenytoin has a direct action on ectopic AVP-producing neuroendocrine tumors. We studied the effect of phenytoin on the release of copeptin, the C-terminal fragment of pro-AVP, and expression of AVP gene in the human small cell lung cancer cell line Lu-165. Cells were maintained in RPMI1640 medium with 10% fetal bovine serum and were used within the fifth passage. Copeptin was detected using a new sandwich immunoassay, and AVP mRNA levels were measured using real-time reverse transcription polymerase chain reaction. Treatment with phenytoin at a concentration of 25 µg/mL, but not at 5 or 10 µg/mL, had an inhibitory effect on copeptin levels in the medium at 48 h. At the same concentration, AVP mRNA levels in Lu-165 cells also decreased. Although a sodium challenge with added sodium at 20 mEq/L increased copeptin levels in the medium, a sodium challenge with added sodium at 10 and 20 mEq/L had no effect on AVP mRNA levels. Phenytoin at a concentration of 25 µg/mL suppressed copeptin levels in the medium under the sodium challenge with added sodium at 10 and 20 mEq/L. Phenytoin at a concentration of 25 µg/mL also decreased AVP mRNA levels in Lu-165 cells under the sodium challenge with added sodium at 10 mEq/L, but not at 20 mEq/L. Among five tested NaV channel subunits, NaV1.3 was highly expressed in Lu-165 cells. However, phenytoin significantly decreased NaV1.3 mRNA levels under the sodium challenge with added sodium at 10 and 20 mEq/L. These results suggest that Lu-165 cells are sensitive to phenytoin and sodium to control of AVP release and its gene expression. Phenytoin might have a direct action on ectopic AVP-producing tumors, suggesting the importance of NaV channels in AVP-producing neuroendocrine tumors.

Amino acid substitutions from an indispensable disulfide bond affect P2X2 receptor activation.

The roles of six amino acid residues downward from an extracellular disulfide bond involving Cys(224) in rat P2X(2) receptor were examined. When Cys(224) or Pro(225) was replaced with alanine, the responsiveness to ATP was lost. When Ile(226) was replaced with other hydrophobic amino acids, the responsiveness to ATP was reduced or abolished. When Phe(227) was replaced with leucine or isoleucine, the responsiveness to ATP was abolished. The responsiveness to ATP was moderately decreased with the alanine-substitution for Arg(228) and it was markedly decreased with the alanine-substitution for Leu(229). As for the alanine-substitution for Gly(230), the sensitivity was changed, but the maximal response to ATP was not reduced. The results suggested that a precise structure is required for amino acid residues close to the disulfide bond and, in general, the amino acid residues at odd number positions and those closer to the disulfide bond are more influential to the ATP responsiveness.

Intracellular disulfide bond that affects ATP responsiveness of P2X2 receptor/channel.

The role of intracellular cysteine residues in P2X(2) receptor/channel was investigated. When dithiothreitol was intracellularly applied, both the maximal response and the sensitivity of the wild-type channel to ATP were decreased. On the other hand, Cu(2+) phenanthroline did not affect the responsiveness. When two intracellular cysteine residues (Cys(9) and Cys(430)) were replaced with alanine, both the maximal response and the sensitivity was decreased with the replacement at Cys(9), whereas no such decrease was observed with the replacement at Cys(430). These results suggest that an intracellular disulfide bond involving Cys(9) regulates the responsiveness of P2X(2) receptor/channel to ATP.

Size of side-chain at channel pore mouth affects Ca(2+) block of P2X(2) receptor.

Effects of amino acid replacement at the channel pore mouth of P2X(2) receptor/channel on multivalent cation channel block were investigated. When Asn(333) was replaced with various amino acid residues with neutral side chains (Gly, Ala, Val, Leu and Ile), the block by Ca(2+) was attenuated according to the sizes of the side chains. The block by La(3+) was also greatest with the Gly-substituted mutant, but this preference was not found for the block by other multivalent cations tested. The side chain at the channel pore mouth may interfere with the access of Ca(2+) block by steric hindrance.

Quantitative structure-cytotoxicity relationship of 3-styrylchromones.

BACKGROUND: Fifteen 3-styrylchromones were subjected to quantitative structure-activity relationship (QSAR) analysis based on their cytotoxicity, tumor selectivity and anti-HIV activity, in order to explore their biological activities. MATERIALS AND METHODS: Cytotoxicity against four human oral squamous cell carcinoma (OSCC) cell lines and three human oral normal cells was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. Tumor-selectivity was evaluated by the ratio of the mean CC50 (50% cytotoxic concentration) against normal human oral cells to that against OSCC cell lines. Anti-HIV activity was evaluated by the ratio of CC50 to EC50 (50% cytoprotective concentration from HIV infection). Physicochemical, structural and quantum-chemical parameters were calculated based on the conformations optimized by the LowModeMD method followed by the density functional theory (DFT) method. RESULTS: All 3-styrylchromone derivatives showed moderate-to-high tumor selectivity. Especially, compounds that have a methoxy group at 6-position of the chromone ring and hydroxyl group at 4'-position of phenyl group in styryl moiety [ 11: ] showed the highest tumor-selectivity. On the other hand, their cytotoxicity against normal cells showed good correlation to the descriptors that reflect hydrophobic interaction and molecular shapes. CONCLUSION: Multivariate statistics with chemical descriptors for the location of substituted group, molecular shape and electrostatic interaction may be useful for designing the most favorable compound with higher tumor selectivity.

BmDJ-1 is a key regulator of oxidative modification in the development of the silkworm, Bombyx mori.

We cloned cDNA for the Bombyx mori DJ-1 protein (BmDJ-1) from the brains of larvae. BmDJ-1 is composed of 190 amino acids and encoded by 672 nucleotides. Northern blot analysis showed that BmDJ-1 is transcribed as a 756-bp mRNA and has one isoform. Reverse transcriptase (RT)-PCR experiments revealed that the BmDJ-1 was present in the brain, fatbody, Malpighian tubule, ovary and testis but present in only low amounts in the silkgland and hemocyte of day 4 fifth instar larvae. Immunological analysis demonstrated the presence of BmDJ-1 in the brain, midgut, fatbody, Malpighian tubule, testis and ovary from the larvae to the adult. We found that BmDJ-1 has a unique expression pattern through the fifth instar larval to adult developmental stage. We assessed the anti-oxidative function of BmDJ-1 using rotenone (ROT) in day 3 fifth instar larvae. Administration of ROT to day 3 fifth instar larvae, together with exogenous (BmNPV-BmDJ-1 infection for 4 days in advance) BmDJ-1, produced significantly lower 24-h mortality in BmDJ-1 groups than in the control. 2D-PAGE revealed an isoelectric point (pI) shift to an acidic form for BmDJ-1 in BmN4 cells upon ROT stimulus. Among the factors examined for their effects on expression level of BmDJ-1 in the hemolymph, nitric oxide (NO) concentration was identified based on dramatic developmental stage-dependent changes. Administration of isosorbide dinitrate (ISDN), which is an NO donor, to BmN4 cells produced increased expression of BmDJ-1 compared to the control. These results suggest that BmDJ-1 might control oxidative stress in the cell due to NO and serves as a development modulation factor in B. mori.

Effect of denuded endothelial cells on arginine amidase activity released from rabbit arteries.

1. We examined the secretion of arginine amidase activity from rabbit aorta and ear arteries. 2. The amount of arginine amidase activity spontaneously secretion from the aorta was significantly less than that secreted from the ear artery. Dermatan sulphate significantly facilitated the secretion of arginine amidase activity from both the aorta and ear artery. 3. The dermatan sulphate-enhanced secretion of arginine amidase activity from the aorta and ear artery was reduced by denudation of the endothelium. 4. These findings may indicate that spontaneous release of arginine amidase activity from vascular smooth muscle and the enhancement of secretion of arginine amidase activity produced by dermatan sulphate depends on the endothelium.