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Neuroblastoma: Maturation and Differentiation
Published in Richard C. Niemtzow, Transmembrane Potentials and Characteristics of Immune and Tumor Cell, 2020
The addition of a depolarizing concentration of veratridine (0.2 mM) to cells differentiated for 1 week increases the passive 22Na+ influx two- to threefold. Similar changes in the veratridine stimulated 22Na+ influx are seen in cells grown in the presence of 5 BrdU, which, like dibutyryl cAMP, results in the extensive process formation of the SY5Y cells. These results are in direct contrast to those obtained with the parental cells (SK-N-SH) in which veratridine does not stimulate the 22Na+ influx and in which cells are not electrically excitable as judged by the absence of action potentials in response to current injection.
Ion Channels and The Control of Uterine Contractility
Published in Robert E. Garfield, Thomas N. Tabb, Control of Uterine Contractility, 2019
Because the fast sodium current peaks within 2–3 ms, capacitive transients have to be reduced by using small cells and electrodes with a relatively low resistance. As myometrial cells are long cylinders, ranging from 80 to 100 μ M in length and from 6 to 12 μ M in width,27 the first 1–3 ms are not properly clamped and the peak current amplitude may be underestimated, especially for the high depolarizing pulses. Neurotoxins such as veratridine and sea anemone toxins have been shown to reveal the voltage-dependent sodium current by stabilizing an open form of the sodium channel.33 When 100 μ M veratridine is applied in the bath solution, the inward calcium channel current is progressively inhibited within 2–3 min.34 After the pulse, there is a standing inward tail current representing a population of veratridine-modified channels that does not close at −80 mV.
Catalog of Herbs
Published in James A. Duke, Handbook of Medicinal Herbs, 2018
Seeds contain 4(1 to 6)% steroid alkaloids which work rather like veratrine, composed mostly (circa 75%) of cebadine (an angelic acid ester of veracevine) (C32H49NO9) and 25% veratridine (a veratric acid ester of veracevine) (C32H49NO9). Vanilloylcevine is hypotensive.1 Also, cevacine (C29H45NO9), vanillylveracevine (C29H45NO11), veracevine (C27H43NO8), neosabadine (C27H43NO8), sabadine (C29H47.49NO8), hydroalkamine S (C27H45NO8), vera-grinine (C3,H53 57NO13), sabatine (C29H47.49NO9). The seed contains 9 to 20% oil composed mostly of palmitic and oleic acids, phytosterols, wax, resin, and angelic-, acetic-, ceva-dic-, chelidonic-, tiglic-, vanillic-, and veratric-acids.2,33
Search for the Source of the Retinal Relaxing Factor
Published in Current Eye Research, 2018
Laura Vanden Daele, Charlotte Boydens, Joke Devoldere, Katrien Remaut, Johan Van de Voorde
The KRB solution contained the following components (mM): NaCl 135, KCl 5, NaHCO3 20, glucose 10, CaCl2 2.5, MgSO4 1.3, KH2PO4 1.2, and EDTA 0.026 in H2O. 120 mM K+ and 30 mM K+ KRB solutions were made by equimolar replacement of NaCl by KCl, and Ca2+-free 30 mM K+ KRB solutions were made by removing CaCl2 without substitution. Veratridine was obtained from Alomone labs (Jerusalem, Israel), and A-803467, DL-α-Aminoadipic acid, and minocycline hydrochloride were obtained from Sigma-Aldrich (St. Louis, MO, USA). All stock solutions were made in DMSO, except for minocycline that was made in water and DL-α-aminoadipic acid that was directly solved in KRB solution. The final concentrations of DMSO in the solutions containing arteries or retinas never exceeded 0.1%.
Hikers poisoned: Veratrum steroidal alkaloid toxicity following ingestion of foraged Veratrum parviflorum
Published in Clinical Toxicology, 2018
Mehruba Anwar, Matthew Turner, Natalija Farrell, Wendy B. Zomlefer, Owen M. McDougal, Brent W. Morgan
Veratrum species can contain many steroidal alkaloids, including the veratrinine (veratridine, veratrine, etc.), jervanine (cyclopamine, cycloposine, jervine, etc.), cevanine, verazine, and solanidine types [3,6]. Veratrum steroidal alkaloids such as veratramine and veratridine cause neuronal sodium channel hyperpermeability, leading to toxicity that manifests initially with gastrointestinal symptoms followed by a Bezold–Jarisch reflex of hypopnea, hypotension, and bradycardia [7]. The cardiogenic effects of Veratrum alkaloids were investigated for therapeutic use in hypertension but this work was abandoned due to its narrow therapeutic index [3]. Veratrum steroidal alkaloids of the jervanine type, such as cyclopamine, are teratogens interfering with the hedgehog-2 signaling pathway, which causes cyclopsia and holoprosencephaly. This pathology was originally described in ewes whose pregnant mothers grazed on V. californium [8]. Human teratogenicity has not been reported. More recently, cyclopamine and cyclopamine derivatives have been investigated as potential therapeutics in cancer [9].
Veratrum parviflorum poisoning: identification of steroidal alkaloids in patient blood and breast milk
Published in Clinical Toxicology, 2022
Jared T. Seale, Joseph E. Carpenter, Matthew D. Eisenstat, Emily A. Kiernan, Brent W. Morgan, Daniel P. Nogee, Xinzhu Pu, Colin A. Therriault, Michael Yeh, Owen M. McDougal
The root and rhizome extract of V. parviflorum yielded a chromatogram with over 53 peaks representing unique constituents (supplemental Figure S7). Commercially available steroidal alkaloid standards for jervine, veratramine, veratridine, cyclopamine, and muldamine were used to identify known alkaloids within the V. parviflorum extract. All steroidal alkaloid standards were present in the plant extract with the exception of veratridine (supplemental Figures S8–S11).