Increased Incorporation of [G‐3h]leucine Into a Possible ‘Receptor’ Proteolipid in Denervated Muscle in Vivo

Abstract—The incorporation of radioactive leucine into the total proteins and the proteolipids of normal and denervated rat diaphragm has been studiedin vivo.Denervation increased the incorporation of isotopically labelled leucine into each of the isolated proteolipids and the effect was particularly marked in a single proteolipid which has been designated a ‘receptor’ proteolipid. In normal muscle this particular proteolipid was found to have a higher incorporation of isotopically labelled leucine in the area of the muscle rich in endplates compared with an area devoid of endplates. However the stimulatory effect of denervation on the incorporation of radioactive leucine into this proteolipid was considerably more marked in the latter region. An attempt has been made to correlate these findings with the development of the hypersensitivity to ACh characteristic of denervated muscle.