17R(18S)-EpETE is an oxylipin and a cytochrome P450 metabolite of eicosapentaenoic acid .1,217R(18S)-EpETE is an activator of large-conductance calcium-activated potassium (BKCa) channels, increasing the potassium current amplitude by 15-fold in isolated rat cerebral artery vascular smooth muscle cells (VSMCs) at +60 mV when used at a concentration of 50 nM.2It has negative chronotropic effects in isolated neonatal rat cardiomyocytes (NRCMs; EC50= ~1-2 nM) and prevents calcium-induced increases in the spontaneous beating of NRCMs.3,4
1.Schwarz, D., Kisselev, P., Ericksen, S.S., et al.Arachidonic and eicosapentaenoic acid metabolism by human CYP1A1: Highly steroselective formation of 17(R), 18(S)-epoxyeicosatetraenoic acidBiochem. Pharmacol.67(8)1445-1457(2004) 2.Lauterbach, B., Barbosa-Sicard, E., Wang, M.H., et al.Cytochrome P450-dependent eicosapentaenoic acid metabolites are novel BK channel activatorsHypertension39(2 Pt. 2)609-613(2002) 3.Falck, J.R., Wallukat, G., Puli, N., et al.17(R),18(S)-Epoxyeicosatetraenoic acid, a potent eicosapentaenoic acid (EPA) derived regulator of cardiomyocyte contraction: Structure-activity relationships and stable analoguesJ. Med. Chem.54(12)4109-4118(2011) 4.Arnold, C., Markovic, M., Blossey, K., et al.Arachidonic acid-metabolizing cytochrome P450 enzymes are targets of omega-3 fatty acidsJ. Biol. Chem.285(43)32720-32733(2010)
Zonisamide-13C2,15N is intended for use as an internal standard for the quantification of zonisamide by GC- or LC-MS. Zonisamide (T0267) is an antiepileptic agent.1 It selectively inhibits the repeated firing of sodium channels (IC50 = 2 μg/ml)in mouse embryo spinal cord neurons and inhibits spontaneous channel firing when used at concentrations greater than 10 μg/ml.2 In rat cerebral cortex neurons,zonisamide (1-1,000 μM)inhibits T-type calcium channels with a maximum reduction of 60% of the calcium current.3 Zonisamide (T0267)inhibits H. pylori recombinant carbonic anhydrase (CA)and the human CA isoforms I,II,and V with Ki values of 218,56,35,and 21 nM,respectively.4,5 In mice,it has anticonvulsant activity against maximal electroshock seizure (MES)and pentylenetetrazole-induced maximal,but not minimal,seizures (ED50s = 19.6,9.3,and >500 mg/kg,respectively). Zonisamide (T0267) (40 mg/kg,p.o.)prevents MPTP-induced decreases in the levels of dopamine ,but not homovanillic acid or dihydroxyphenyl acetic acid ,and increases MPTP-induced decreases in the dopamine turnover rate in mouse striatum in a model of Parkinson's disease.6 Formulations containing zonisamide have been used in the treatment of partial seizures in adults with epilepsy.
Eltoprazine(DU28853) is a serenic or antiaggressive agent which as an agonist at the 5-HT1A and 5-HT1B receptors and as an antagonist at the 5-HT2C receptor.IC50 value:Target: 5-HT1A/1B agonist; 5-HT2C antagonistin vitro: The binding of [3H]eltoprazine to whole tissue sections was saturable and revealed an apparent dissociation constant (Kd) of 11 nM. Specific [3H]eltoprazine binding was completely displaced by 5-HT; conversely, unlabelled eltoprazine reduced [3H]5-HT binding to the levels of non-specific binding [1]. Eltoprazine evoked membrane changes that were similar to but much weaker than those induced by 5HT. Both the 5HT- and eltoprazine-evoked membrane hyperpolarizations were largely suppressed in the presence of spiperone [2].in vivo: eltoprazine is extremely effective in suppressing dyskinesia in experimental models, although this effect was accompanied by a partial worsening of the therapeutic effect of l-dopa. Interestingly, eltoprazine was found to (synergistically) potentiate the antidyskinetic effect of amantadine. The current data indicated that eltoprazine is highly effective in counteracting dyskinesia in preclinical models [3]. Rats were chronically treated with mianserin (10 mg/kg i.p.) or eltoprazine (1 mg/kg i.p.) and were tested in the elevated plus-maze test for anxiety. Mianserin and eltoprazine displayed opposite effects in the elevated plus-maze: mianserin induced anxiolytic-like effects, while eltoprazine showed anxiogenic-like ones [4].
[1]. Sijbesma H, et al. Eltoprazine, a drug which reduces aggressive behaviour, binds selectively to 5-HT1 receptor sites in the rat brain: an autoradiographic study. Eur J Pharmacol. 1990 Feb 20;177(1-2):55-66. [2]. Joels M, et al. Eltoprazine suppresses hyperpolarizing responses to serotonin in rat hippocampus. J Pharmacol Exp Ther. 1990 Apr;253(1):284-9. [3]. Bezard E, et al. Study of the antidyskinetic effect of eltoprazine in animal models of levodopa-induced dyskinesia. Mov Disord. 2013 Jul;28(8):1088-96. [4]. Rocha B, et al. Chronic mianserin or eltoprazine treatment in rats: effects on the elevated plus-maze test and on limbic 5-HT2C receptor levels. Eur J Pharmacol. 1994 Sep 1;262(1-2):125-31.
Chlorahololide C is a potent and selective potassium channel blocker, it exerts potent and selective inhibition on the delayed rectifier (I(K)) K(+) current with the IC(50) value of 3.6 +/- 10.1 mu M.