We have examined the localization and numbers of @entity934 receptors (AChRs) within adult @entity1 skeletal muscle using 125I-alpha-bungarotoxin (125I-alpha-BuTx). Intracellular AChRs were exposed to 125I-alpha-BuTx by permeabilizing the muscle membrane with the detergent @entity3857 . Our results show that, in muscles of young adult @entity35 , internal AChRs occur in a number and pattern of distribution similar to that for surface membrane AChRs. Internal AChRs are found only in perijunctional regions of normally innervated muscles, but they appear all along the length of muscle fibers after denervation. A minority of internal AChRs may be newly synthesized AChRs en route to insertion in the surface membrane; however, most internal AChRs appear to be antigentically different from and to behave independently of surface membrane AChRs. With increasing age, internal AChRs decline in number, while surface AChRs remain relatively constant. In older animals, internal AChRs may reappear in muscles that have undergone degeneration and regeneration. We conclude that a significant proportion of AChRs in skeletal muscle may be intracellular. Internal AChRs are a useful marker for young muscle cells. Their distribution may provide information about the intracellular pathways of @entity9176 metabolism.

Intracellular XXXX receptors in skeletal muscles of the adult @entity35 .

@entity1 :: ('9606', 'Species') :: ['mammalian'] @entity9176 :: ('170945(Tax:10116)', 'Gene') :: ['AChR'] @entity3857 :: ('MESH:D012503', 'Chemical') :: ['saponin'] @entity35 :: ('10116', 'Species') :: ['rats'] @entity934 :: ('MESH:D000109', 'Chemical') :: ['acetylcholine']
@entity934 :: (MESH:D000109,Chemical) :: ['acetylcholine']
