Turnover of the molecular forms of acetylcholinesterase in the rat diaphragm

J Neurochem. 1982 Feb;38(2):588-90. doi: 10.1111/j.1471-4159.1982.tb08667.x.

Abstract

The turnover of acetylcholinesterase (AChE) and its molecular forms was measured by following the loss of enzyme activity in the right hemidiaphragms of Sprague-Dawley rats treated with cycloheximide, 20 mg/kg, every 4 h. This treatment inhibited 96% of the incorporation of [3H]leucine into muscle protein. After 8 h of treatment, the total AChE activity of the diaphragm decreased by 17% (P less than 0.01). Assuming first-order exponential kinetics, a half-life of 30 h and an hourly turnover of 180 units were calculated. The measured accumulation of AChE activity at a ligature on the phrenic nerve indicated that axonal transport contributed trivially to this turnover. Sucrose density gradient experiments showed that the cycloheximide-induced low of AChE activity was restricted to the 4S enzyme, which had an apparent half-life of 6.2 h.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Acetylcholinesterase / metabolism*
  • Animals
  • Cycloheximide / pharmacology
  • Half-Life
  • Isoenzymes / metabolism*
  • Kinetics
  • Muscles / metabolism*
  • Rats
  • Rats, Inbred Strains

Substances

  • Isoenzymes
  • Cycloheximide
  • Acetylcholinesterase