alpha-Bungarotoxin interacts with the rat brain tachykinin receptors.

alpha-Bungarotoxin (alpha Bgt) was shown to inhibit the binding of the 125I-labeled substance P (SP) and eledoisin (EL) to the rat brain membranes with Kl values of 8.0 +/- 5.0 x 10(-8) and 1.

[Tachykinin receptors in the rat brain bind alpha-bungarotoxin].

alpha-Bungarotoxin was found to inhibit effectively the binding of 125I-labelled substance P and eledoisin to membrane and to solubilize preparations of the rat brain. Other postsynaptic neurotoxins exerted similar but less pronounced influence on the interaction of tachykinins with their receptors. The obtained results suggest that some alpha-bungarotoxin-binding polypeptides in brain are components of tachykinin receptors.

[Interaction of cyclic analogs of substance P with rat brain membranes].

Inhibition of binding of a substance P radioactive derivative with rat brain membranes by cyclic analogues of substance P was studied. The most active cyclic analogue had the inhibition constant 3 mM.