Cell lines

Rat pituitary melanotropic cells

Preparation Method

Reaction Conditions

1 or 10 µM

Applications

1 µM ω-Conotoxin GVIA blocked the high voltage-activated current by 25.5±3.6%. The block at 10µM ω-Conotoxin GVIA was 22.9±2.5% (not significantly different from the block by 1µM;n = 3), indicating thatω-Conotoxin GVIA yields a saturating effect.

Animal models

male COBS CD (SD) rats

Preparation Method

In these animals the intravenous administration of graded doses of ω-Conotoxin GVIA (1--2 nmol/kg)

Dosage form

Intravenous injection, 1--2 nmol/kg

Applications

Intravenous injection caused a progressive loss of tension development of tibialis muscle indirectly evoked by the electrical stimulation of the sciatic nerve, ω-Conotoxin GVIA (1 nmol/kg i.v.) reduced the strength of muscle contraction by 75% in about 27 min (from

ω-Conotoxin GVIA is a cone snail toxin that selectively blocks N-type channels in neurons^[1].

ω-Conotoxin GVIA binds to human neocortical, rat hippocampal, and chick brain synaptic plasma membranes (IC50s = 4.6, 60, and 150 pM, respectively, in radioligand binding assays)^[3,4,5].

ω-Conotoxin GVIA markedly reduced the amplitude of the tetanic contractions of the tibialis anterior muscle in mice, but tetanic facilitation was not impaired. The muscle contractions elicited by direct electrical stimulation were not significantly modified by ω-Conotoxin GVIA. ω-Conotoxin GVIA did not had any significant changes in systemic blood pressure^[5].

References:
[1]. H.D. Mansvelder, J.C. Stoof, K.S. Kits. Dihydropyridine block of ω-agatoxin IVA- and ω-conotoxin GVIA-sensitive Ca2+ channels in rat pituitary melanotropic cells.Eur. J. Pharmacol., 311 (1996), pp. 293-304
[2]. Feuerstein, T.J., Dooley, D.J., and Seeger, W. Inhibition of norepinephrine and acetylcholine release from human neocortex by ω-conotoxin GVIA. J. Pharmacol. Exp. Ther. 252(2), 778-785 (1990).
[3]. Lampe, R.A., Lo, M.M., Keith, R.A., et al. Effects of site-specific acetylation on ω-conotoxin GVIA binding and function. Biochemistry 32(13), 3255-3260 (1993).
[4]. Sato, K., Park, N.G., Kohno, T., et al. Role of basic residues for the binding of ω-conotoxin GVIA to N-type calcium channels. Biochem. Biophys. Res. Commun. 194(3), 1292-1296 (1993).
[5]: Rossoni G, Berti F, La Maestra L, Clementi F. ω-Conotoxin GVIA binds to and blocks rat neuromuscular junction. Neuroscience Letters. 1994;176:185-188.