Denervation supersensitivity in skeletal muscle: analysis with a cloned cDNA probe
نویسندگان
چکیده
Motor neurons regulate the acetylcholine sensitivity of the muscles they innervate: denervated muscle fiber become "supersensitive" to acetylcholine, due to insertion of newly synthesized acetylcholine receptors (AChRs) in the plasma membrane. We used hybridization analysis with a cloned cDNA specific for AChR alpha-subunit to compare the abundance of AChR mRNA in innervated and denervated adult mouse muscles. Within 3 d of denervation, levels of AChR mRNA increased 100-fold; levels of actin mRNA changed little. The increase in AChR mRNA level was sufficiently large and rapid to account for denervation supersensitivity.
منابع مشابه
Modulation of sodium-channel mRNA levels in rat skeletal muscle.
Action potentials in many types of excitable cells result from changes in permeability to Na ions. Although these permeability changes in nerve and muscle are mediated by voltage-gated Na channels that are functionally similar, we found that the Na-channel gene expressed in skeletal muscle is different from the genes coding for two Na channels (type I and type II) in brain. Despite the structur...
متن کاملCellular adaptation: journey from smooth muscle cells to neurons.
In the 1960s, it became clear that the adaptation of smooth muscle to denervation was different from that of skeletal muscle. The supersensitivity of denervated smooth muscle extended to agonists unrelated to the lost neurotransmitter and developed on a tissue-dependent time course of several days to several weeks. Several procedures, in addition to denervation, that interrupted excitatory tran...
متن کاملAcetylcholine and adrenaline-noradrenaline sensitivity in denervated parotid gland of monkey.
The mechanism underlying a phenomenon of such a general occurrence as the supersensitivity after denervation has often been attributed to a decrease of the enzyme cholinesterase in the tissues concerned. Different organs exhibit varying degrees of hypersensitivity; skeletal and smooth muscle, glands, autonomic ganglion cells and neurones of the spinal cord and brain all develop this post-denerv...
متن کاملParasympathetic denervation supersensitivity in the rat iris sphincter muscle: an in vitro study.
Supersensitivity in chronically sympathectomized smooth muscle has long been studied, but little is known about chronically parasympathectomized smooth muscles. Iris is one of the few smooth muscle organs which can be parasympathetically denervated. We used rats because the denervation supersensitivity in the vas deferens has extensively been studied in this species. The rat was unilaterally ci...
متن کاملA comparative study of changes in innervation and development of supersensitivity in the rat vas deferens after various procedures.
The relationship between morphological and functional changes in adrenergic nerves and the development of supersensitivity in the rat vas deferens was comparatively investigated after surgical denervation, chemical sympathectomy by 6-hydroxydopamine, daily treatment of animals with reserpine, or local application of colchicine to the hypogastric plexus. The order of ability to produce supersens...
متن کامل