Nuclease and caspase activities that promote death signals and cause apoptosis are dependent to potassium ion.
The aim of this study was to investigate the effect of potassium channel blocker tetraethylammonium (TEA) on prevention of Parkinson's disease in rats.
This experimental study was conducted on 33 male rats in Qazvin University of Medical Sciences, 2014. 6-hydroxydopamine (6-OHDA) was injected into the striatum of the brain. The rats received different doses of TEA twice daily the day before the 6-OHDA injection till 15 days after the injection. The severity of Parkinsonism was assessed by the apomorphine-induced rotational behavior, the elevated body swing test (EBST), and the rotarod test. Data were analyzed using Kruskal Wallis and Mann Whitney U tests.
Findings: Pretreatment with 5 mg/kg TEA significantly reduced the severity of rotations compared to the saline group. TEA did not reduce the swings in the EBST. In the rotarod test, TEA caused significant improvement in the motor performance of the rats.
With regards to the results, it seems that pretreatment with TEA can partly reduce the severity of behavioral symptoms in the 6-OHDA-induced chronic Parkinson's disease. The higher the TEA dose, the more significant the reduction in the severity of symptoms.

The vasorelaxant effect of estrogens on blood vessels is one of the important cardiovascular protective mechanisms of estrogen. The present experiments were designed to study the mechanisms of vasorelaxant effect of 17β-estradiol (E2) in human saphenous veins (HSV). HSV were obtained from patients undergoing coronary artery bypass graft surgery in Tabriz Madani Heart Center. The role of K+ channels and endothelium derived hyperpolarizing factor (EDHF) in the effects of E2 were studied by incubating tissues with K+ channels blockers: glibenclamid (3μM), 4-aminopyridin (1mm), tetraethyl ammonium (TEA, at lower and higher concentration: 1mm and 10mM), BaCl2 (30μM) and combination of charybdotoxin and apamin. In order to assess the role of endothelium in the inhibitory effect of TEA (10mM) on the relaxant effect of E2, responses were elicited in endothelium denuded vein rings. TEA at 1mm, (selective inhibitor of large-conductance, BKCa, Ca2+ activated K+ channels), 4- aminopyridin (selective inhibitor of voltage dependent K+ channels) and glibenclamid (selective inhibitor of ATP dependent K+ channels) did not affect the vasorelaxant effects of E2 on PGF2α-induced contractions. TEA at higher concentration, an inhibitor of small-conductance (SKCa) and intermediate-conductance (IKCa) Ca2+ activated K+ channels, significantly inhibited E2-induced vasorelaxation. This inhibitory effect was endothelium-dependent and abolished by endothelium denuding. In intact tissues, pretreatment either with a combination of charybdotoxin and apamin (inhibitors of EDHF), or BaCl2, significantly reduced the relaxation produced by E2. The data suggest that vasorelaxant effect of E2 in HSV maybe mediated by EDHF which involves apamin/charybdotoxin-sensitive K+-channels and K+.

In spite of the use of industrially prepared drugs for control of diarrhea complications, the attempts to find plants that reduce intestinal smooth muscle motility are going on. The plant celery (Apium Graveolens) from Apiaceae with both nutritional and pharmacological properties contains flavonoids and has hypotensive, antinociceptive, anti- inflammatory and diuretic effects. The aim of the present study was to investigate the antispasmodic effect of celery leaf extract on the rat ileum. Celery leaf powder was extracted by maceration in 70% alcohol for 72 hours. A terminal portion of ileum from Wistar male rat was dissected and its contractions were recorded isotonically under one gram tension in an organ bath containing Tyrode solution. t-test, and one and two-way ANOVA were used to compare the results. Extract cumulative concentrations (0.25, 0.5, 1, 2 and 4 mg/ml) reduced the ileum contractions induced by KCl (60 mM) and carbachol (10 μM) dose-dependently (ANOVA, P<0.0001). The antispasmodic effect of extract was not reduced by tissue incubation with propranolol (1 μM, 30 min), naloxone (1 μM, 30 min), L-NAME (100μM, 20 min), glibenclamide (10 μM, 5 min) and tetraethylammonium (1 mM, 5 min). In Ca2+-free with high K+ (60 mM) Tyrode solution, the extract (1mg/ml) reduced the ileum contractions induced by cumulative concentrations of CaCl2 (5-8 mM) dose-dependently (two way ANOVA, P<0.0001). Celery leaf extract inhibited the ileum contractions dose dependently. It seems that voltage dependent calcium channels and receptor-operated calcium channels are involved in this activity, but β-adrenoceptors, opioid receptors, NO, and potassium channels are not involved in this effect. It is possible that apigenin as the celery flavonoid is responsible for this activity.

Calcium spikes play important roles in the control of neuronal spontaneous activity. Cerebellar Purkinje neurons fire spontaneous calcium spikes. In this study, the role of potassium channels in the regulation of these spikes was studied. Brain slices from the cerebellum of young rats were prepared and the Purkinje cells were visualized using an upright microscope. Using borosilicate micropipettes and Axoclamp 2B amplifier, intracellular recordings were taken from the cells. The role of different K+ channels in the regulation of calcium spikes configuration was determined using different K+ channels blockers and precise analysis of the recorded calcium spikes in the presence of blockers. Application of wide-range 4-aminophyridine and tetraethylammonium blockers increased duration and amplitude of afterhyperpolarization (AHP) of the calcium spikes and converted them from one-peak spike to two- or multiple-peaks spikes. Blockade of small conductance calcium dependent potassium channels increased duration of the spikes but had no effect on the AHP amplitude Blockade of large conductance calcium dependent potassium channels increased duration of the calcium spikes and decreased the AHP amplitude. Our results showed that properties of the calcium spikes in the cerebellar Purkinje neurons were largely controlled by different potassium channels, including calcium dependent types.

4-aminopyridine (4-AP) and tetraethylammonium (TEA) are two potassium channel blockers which have shown that have beneficial effects in treating some neurological disorders such as ataxia, Alzheimer and multiple sclerosis. In this study the effect of acute administration of 4-AP and TEA in the treatment of behavioral symptoms of Parkinsonism induced by the toxin 6-hydroxydopamine (6-OHDA) was studied in male rats. 6-OHDA was injected into left medial forebrain bundle (MFB) by stereotaxic surgery using Hamilton syringe. Then, in the third week after surgery, the rats before and after drug application were tested for rotational behavior induced by apomorphine. In the fourth week, Rotarod test was performed in the presence of the blockers for six consecutive days. 4-AP at doses 200 and 500 µg/kg had no significant effect, but at dose 1000 µg/kg led to a significant improvement of behavioral symptoms of Parkinsonism in the rotation test. On the other hand, the drug decreased motor performance and motor learning in the Rotarod test. TEA at dose 1 mg/kg was ineffective, but at dose 2 mg/kg caused a significant decrease, and at dose 5 mg/kg caused a significant increase in the number of rotations of the Parkinsonian rats. TEA had no effect on the motor learning in the Rotarod test. The results of this study indicate that 4-AP and TEA, in a dose-dependent manner, weaken some symptoms of Parkinsonism, but worsen some other symptoms.

In this study, the synthesis of nano-porous calcium magnesium silicate was performed and studied to improve drug properties and drug release. This synthesis was carried out by using the tetraethyl ortho silicate precursor (TEOS) and the Cetyltrimethyl ammonium bromide surfactant (CTAB) in a sol-gel alkaline environment; and the product was heat treated at 600° C and 800° C temperatures. The purpose of this study is to investigate the effect of the calcination temperature on the potential for ibuprofen release by the production produced compound. The product was studied using X-ray diffraction patterns (XRD), Nitrogen adsorption / desorption, Fourier-transform infrared spectroscopy (FTIR), ultraviolet spectroscopy (UV) and Transmission electron microscopy (TEM), and field emission scanning electron microscopy (FE-SEM). The results of Nitrogen absorption-desorption assay showed a surface area of 42-140 m2 /g The drug release after 240 hours showed that the calcite sample had a lower release at 600 ° C, temperature that which was is due to the smaller size of the cavities and the more surface area, as compared tothan the other specimens. Also, calcium and magnesium elements increased the loading capacity, and createcreating a suitable substrate for for the slower drug release. Overall, This this study showed that nano-porous magnesium silicate calcium has had the ability to load and release the ibuprofen and can could be, therefore, used as a modern drug delivery system in the bone tissue engineering field.

Transplantation of embryonic ventral mesencephalic (VM) dopamine neurons into the striatum is a currently explored therapeutic strategy for treatment of patients with patients with Parkinson''s disease (PD). However, this strategy has been limited with poor cell survival, generally ranging from 5-20%. In this study, we investigated the effect of potassium channel blocker of tetraethylammonium (TEA) and B vitamins supplementation on the efficacy of cell replacement therapy in the treatment of 6-hydroxydopamine (6-OHDA)-induced Parkinsonism. Cell suspension was prepared from embryonic day 14 (E14) VM of rat fetuses and was transplanted into striatum of Parkinsonian rats after overnight hibernation with TEA or B vitamins. The Parkinsonian rats were also treated with TEA or B vitamins for two weeks after transplantation. Severity of Parkinsonism was assessed by apomorphine-induced rotational test in several steps before and after transplantation. 1- Transplantation of VM cell suspension significantly decreased behavioral symptoms of Parkinsonism in the apomorphine-induced rotational test. 2-TEA treatment further decreased these symptoms. 3- B vitamins treatment had no additional effect in amelioration of the symptoms. 4-Treatment with both TEA and B vitamins also further decreased behavioral symptoms, which in one post-transplantation test was even more than the effect of TEA alone. TEA, especially in combination with B vitamins supplementation, can increase the efficacy of cell replacement therapy in the 6-OHDA rat PD model.

Ammonium uranyl carbonate (AUC), an intermediate material in the process of conversion of yellowcake to uranium hexafluoride, was produced by injection of an aqueous solution of ammonium carbonate (AC) into uranyl nitrate solution. The target parameter in optimization of this process was the yield of the precipitation, as morphology and size distribution of AUC play no role in its post processing to UF6. The aim of the current study was the experimental investigation of the effects of the process variables on the yield of AUC precipitation. The results showed that the flow rate and flow pattern of the injection of the AC solution, aging time, impeller speed, and temperature had little effects on the yield of AUC precipitation. On the other hand, the yield was increased by increasing the ammonium carbonate to uranyl nitrate molar ratio, ammonium carbonate concentration, and uranyl nitrate concentration. However, it decreased by increasing the molar ratio of CO32- to NH4+ ions in the ammonium carbonate solution.