BIOLOGY 3P03 Lecture Notes - Lecture 14: Vascular Smooth Muscle, Pertussis, Amlodipine
5 Feb 2017
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N. b. the value of er is above action potential threshold hence ach is excitatory at skeletal. Nmj: ap tends to excite the muscle by driving the membrane potential towards a level above the ap threshold. In the context of a real cell, the ap is triggered even before the membrane potential an get close to er. End-plate recordings (epc) at negative potentials under voltage clamp. C. in normal muscle (i. e. not voltage clamped) the inward epc depolarizes the muscle cell, giving rise to an end-plate potential (epp) Typically, the depolarization is suprathreshold resulting in an ap in the muscle. Biochemical studies on nicotinic achr aided by availability of snake toxins that bind with high affinity: e. g. Bungarotoxin (from formosan snake bungarus multictinus) binds almost irreversibly to nachr in skeletal muscle (competitive inhibitor) Aided in purification of the receptor protein. Curare (used by indians in darts during hunting) is also a competitive inhibitor of nachr.
