Expression of three distinct families of calcium-activated chloride channel genes in the mouse dorsal root ganglion

Objective A calcium-activated chloride current （ICl（Ca）） has been observed in medium-sized sensory neurons of the dorsal root ganglion （DRG）. Axotomy of the sciatic nerve induces a similar current in the majority of medium and large diameter neurons. Our aim is to identify the molecule（s） underlying this current. Methods Using conventional and quantitative RT-PCR, we examined the expression in DRG of members of three families of genes, which have been shown to have latch） current inducing properties. Results We showed the detection of transcripts representing several members of these families, i.e. chloride channel calciumactivated （CLCA）, Bestrophin and Tweety gene families in adult DRG, in the normal state and 3 d after sciatic nerve section, a model for peripheral nerve injury. Conclusion Our analysis revealed that that mBestl and Tweety2 appear as the best candidates to play a role in the injury-induced Icl（Ca） in DRG neurons.

Effects of Trinitrotoluene on Serum Phosphorylase A Activities and on Calcium Contents in Men and Rats

Wistar rats were exposed to trinitrotoluene (TNT) for 6 weeks. After initiation of TNT exposure, serum phosphorylase A activities and calcium contents were assayed for every 2 weeks. Both of these 2 parameters increased in rats treated with 50 and 100 mg TNT/kg b.w. at 3 intervals. Serum phosphorylase A activities and calcium contents of TNT exposure worker increased too.

Pharmacological evaluation of smooth muscle relaxant and cardiac-modulation potential of Phyla nodiflora in ex-vivo and in-vivo experiments

Objective: To investigate the pharmacological basis of its uses of Phyla nodiflora(P. nodiflora) for the treatment of anomalies predominantly by smooth muscle containing tissues such as gastrointestinal/vascular/broncho spasm and cardiovascular modulation.Methods: The crude hydroalcoholic extract of P. nodiflora(Pn.Cr) and its fractions were evaluated on isolated rabbit jejunum, rat trachea, aorta and atrium. To access the contractile or relaxant effects of testing materials, the tissues were mounted in isolated organ bath and responses were recorded with transducers coupled with data acquisition system.BALB/c mice were challenged with castor oil for the assessment of in-vivo antidiarrheal activity. Normotensive rats were used for in-vivo hypotensive study.Results: Hydroalcoholic extract of Pn.Cr at variable concentrations inhibited the natural spontaneous rhythm and 80 mmol/L K^+ mediated contractions in isolated segment of jejunum with EC_(50) values of 3.18 and 1.91 mg/mL respectively. Verapamil, a Ca^(2+) channel blocker, demonstrated akin pattern in jejunum and therefore possibly suggesting calcium blocking activity. On isolated rat tracheal tissue, Pn.Cr showed relaxation of high-K^+and carbachol mediated contractions(EC_(50) values: 1.24 and 2.42 mg/mL). Pn.Cr treatment relaxed the rat aortic ring in a cumulative doses with high-K^+ and phenylephrine-induced contractions(EC_(50) values 0.25 and 0.92 mg/mL). Activity based fractionation of Pn.Cr showed that dichloromethane fraction was more potent for relaxing the tissues spasm compared to aqueous fraction. In-vivo experiments, significant protection by Pn.Cr(P < 0.05) was observed in castor oil-induced diarrhea(50–500 mg/kg)whereas hypotensive effect in anesthetized rats was seen at the dose range of 1–10 mg/kg of Pn.Cr(P < 0.05).Conclusion: This study suggests the blockage of calcium channel in the smooth muscles as a pharmacological application to make usage of P. nodiflora in the management of diarrhea, asthma and hypotensive effect.

Preparation of Ammonia Adsorbent by Carbonizing and Activating Mixture of Biomass Material and Hygroscopic Salt

We put forward a new and ingenious method for the preparation of a new adsorbent by soaking, carbonizing and activating the mixture of hygroscopic salt and biomass material. The new adsorbent has high porosity, uniform distribution and high content of Ca Cl2, and exhibits high adsorption performance. The ammonia uptake and specific cooling power（SCP） at 5 min adsorption time can reach as high as 0.19 g·g^-1 and 793.9 W·kg^-1, respectively. The concept of utilizing the biomass materials and hygroscopic salts as raw materials for the preparation of adsorbents is of practical interest with respect to the potential quantity of biomass materials around the world, indicating that there would be a new market for biomass materials.Key words： biomass material; adsorption system; ammonia; calcium chloride; activated carbon

Experimental Design Technique on Removal of Hydrogen Sulfide using CaO-eggshells Dispersed onto Palm Kernel Shell Activated Carbon：Experiment,Optimization,Equilibrium and Kinetic Studies

This study presents the use of chicken eggshells waste utilizing palm kernel shell based activated carbon（PKSAC） through the modification of their surface to enhance the adsorption capacity of H2S. Response surface methodology technique was used to optimize the process conditions and they were found to be： 500 mg/L for H2S initial concentration, 540 min for contact time and 1 g for adsorbent mass. The impacts of three arrangement factors（calcination temperature of impregnated activated carbon（IAC）, the calcium solution concentration and contact time of calcination） on the H2S removal efficiency and impregnated AC yield were investigated. Both responses IAC yield（IACY, %） and removal efficiency（RE, %） were maximized to optimize the IAC preparation conditions. The optimum preparation conditions for IACY and RE were found as follows： calcination temperature of IAC of 880 ℃, calcium solution concentration of 49.3% and calcination contact time of 57.6 min, which resulted in 35.8% of IACY and 98.2% RE. In addition, the equilibrium and kinetics of the process were investigated. The adsorbent was characterized using TGA, XRD, FTIR, SEM/EDX, and BET. The maximum monolayer adsorption capacity was found to be 543.47 mg/g. The results recommended that the composite of PKSAC and Ca O could be a useful material for H2S containing wastewater treatment.

L-type calcium current in right ventricular outflow tract myocytes of rabbit heart

The mechanism of idiopathic ventricular tachycardia originating from the right ventricular outflow tract （RVOT） is not clear. Many clinical reports have suggested a mechanism of triggered activity. However, there are few studies investigating this be- cause of the technical difficulties associated with examining this theory. The L-type calcium current （/Ca-L）, an important in- ward current of the action potential （AP）, plays an important role in arrhythmogenesis. The aim of this study was to explore differences in the APs of right ventricular （RV） and RVOT cardiomyocytes, and differences in electrophysiological character- istics of the ICa-L in these myocytes. Rabbit RVOT and RV myocytes were isolated and their AP and Ic,-L were investigated us- ing the patch-clamp technique. RVOT cardiomyocytes had a wider range of AP duration （APD） than RV cardiomyocytes, with some markedly prolonged APDs and markedly shortened APDs. The markedly shortened APDs in RVOT myocytes were abolished by treatment with 4-AP, an inhibitor of the transient outward potassium current, but the markedly prolonged APDs remained, with some myocytes with a long AP plateau not repolarizing to resting potential. In addition, early afterdepolariza- tion （EAD） and second plateau responses were seen in RVOT myocytes but not in RV myocytes. RVOT myocytes had a high- er current density for/Ca-L than RV myocytes （RVOT （13.16±0.87） pA pF-1, RV （8.59±1.97） pA pF-1; P〈0.05）. The ICa-L and the prolonged APD were reduced, and the EAD and second plateau response disappeared, after treatment with nifedipine （10 μmol L^-1）, which blocks the Ica-L. In conclusion, there was a wider range of APDs in RVOT myocytes than in RV myocytes, which is one of the basic factors involved in arrhythmogenesis. The higher current density for ICa-L is one of the factors causing prolongation of the APD in RVOT myocytes. The combination of EAD with prolonged APD may be one of the mechanisms of RVOT-VT generation.

Flunarizine inhibits sensory neuron excitability by blocking voltage-gated Na＋ and Ca2＋ currents in trigeminal ganglion neurons

Background Although flunarizine has been widely used for migraine prophylaxis with clear success, the mechanisms of its actions in migraine prophylaxis are not completely understood. The aim of this study was to investigate the effects of flunarizine on tetrodotoxin-resistant Na＋ channels and high-voltage activated Ca2＋ channels of acutely isolated mouse trigeminal ganglion neurons. Methods Sodium currents and calcium currents in trigeminal ganglion neurons were monitored using whole-cell patch-clamp recordings. Paired Student＇s t test was used as appropriate to evaluate the statistical significance of differences between two group means. Results Both tetrodotoxin-resistant sodium currents and high-voltage activated calcium currents were blocked by flunarizine in a concentration-dependent manner with the concentration producing half-maximal current block values of 2.89 μmol/L and 2.73 μmol/L, respectively. The steady-state inactivation curves of tetrodotoxin-resistant sodium currents and high-voltage activated calcium currents were shifted towards more hyperpolarizing potentials after exposure to flunarizine. Furthermore, the actions of flunarizine in blocking tetrodotoxin-resistant sodium currents and high-voltage activated calcium currents were use-dependent, with effects enhanced at higher rates of channel activation. Conclusion Blockades of these currents might help explain the peripheral mechanism underlying the preventive effect of flunarizine on migraine attacks.

Highlights for the 6th International Ion Channel Conference:ion channel structure,function,disease and therapeutics

To foster communication and interactions amongst international scholars and scientists in the field of ion channel research, the 6 th International Ion Channel Conference(IICC-2017) was held between June 23–27, 2017 in the eastern coastal city of Qingdao, China. The meeting consisted of 450 attendees and 130 speakers and poster presenters. The program consisted of research progress, new findings and ongoing studies that were focused on(1) Ion channel structure and function;(2) Ion channel physiology and human diseases;(3) Ion channels as targets for drug discovery;(4) Technological advances in ion channel research. An insightful overview was presented on the structure and function of the mechanotransduction channel Drosophila NOMPC(No mechanoreceptor potential C), a member of the transient receptor potential(TRP) channel family. Recent studies on Transmembrane protein 16 or Anoctamin-1(TMEM16A, a member of the calcium-activated chloride channel [CaCC] family) were summarized as well. In addition, topics for ion channel regulation, homeostatic feedback and brain disorders were thoroughly discussed. The presentations at the IICC-2017 offer new insights into our understanding of ion channel structures and functions, and ion channels as targets for drug discovery.