Patent ID: 8759093

Claim:
A method for determining the selectivity of a pre-synaptic neuromuscular blocking substance comprising the following steps: (a) determining the minimum voltage V mst needed to induce the contraction of a striated muscle tissue, said striated muscle tissue being connected to an electrical stimulator through a motor nerve; (b) adding to the system of step (a) a pre-determined quantity of a pre-synaptic neuromuscular blocking substance; (c) electrically stimulating, at a voltage at least equal to V mst , the muscle tissue by train pulse stimulation, thereby extending life span of the muscle tissue and carrying out the stimulation over a period of at least 1 hour to increase the sensitivity of the method; (d) measuring the effect induced by the pre-determined quantity of a pre-synaptic neuromuscular blocking substance on the striated muscle tissue, said effect being selected from (i) time to paralysis of said striated muscle tissue, (ii) variation in the contraction rate of said striated muscle tissue, (iii) variation in the contraction distance of said striated muscle tissue, (iv) variation in the force of contraction of said striated muscle tissue, and (v) variation in the end plate potential or the miniature end plate potential of said striated muscle tissue; (e) determining the minimum voltage V msm needed to induce the contraction of a smooth muscle tissue, said smooth muscle tissue being linked to an electrical stimulator through an electrically conducting liquid; (f) adding to the system of step (e) the same pre-determined quantity of the same pre-synaptic neuromuscular blocking substance as for step (b); (g) electrically stimulating, at a voltage at least equal to V msm , the muscle tissue by train pulse stimulation, thereby extending life span of the muscle tissue and carrying out the stimulation over a period of at least 1 hour to increase the sensitivity of the method; (h) measuring the effect induced by said pre-determined quantity of the pre-synaptic neuromuscular blocking substance on the smooth muscle tissue, said effect being selected from (i) time to paralysis of said smooth muscle tissue, (ii) variation in the contraction rate of said smooth muscle tissue, (iii) variation in the contraction distance of said smooth muscle tissue, (iv) variation in the force of contraction of the smooth muscle tissue, and (v) variation in the end plate potential or the miniature end plate potential of said smooth muscle tissue; and (i) calculating the quotient of the result obtained in step (h) by the result obtained in step (d), wherein, the higher above 1 said quotient is, the more selective for smooth muscle the pre-synaptic neuromuscular blocking substance is; or, conversely, calculating the quotient of the result obtained after step (d) by the result obtained after step (h), wherein, the higher above 1 said quotient is, the more selective for striated muscle the pre-synaptic neuromuscular blocking substance is.