Age-induced alteration of neuromuscular transmission: effect of halothane.
Age-induced alteration in neuromuscular transmission and the effect of halothane were examined in 3- and 30-month-old rats with the voltage clamp technique. Significant pre- and post-junctional changes of synaptic transmission occur with advancing age as the frequency of spontaneous release, quantal content and mobilization rate increase and decay time (tau) of miniature end plate current (MEPC) and end-plate current (EPC) is prolonged and altered (bi-exponential). Effects of halothane (0.3-0.88 mM) appeared to be pre-junctional, as the anesthetic decreased the frequency of spontaneous release, end plate current amplitude, quantal content and mobilization rate, had little or no effect on decay time of miniature end plate current and end plate current, and produced no run-down of ionophoretically evoked trains of end plate current. Some of these effects of halothane are more prominent in 30-month-old rats.
Bhattacharyya
B J
BJ
Department of Neurology, University of Minnesota, Minneapolis.
Tsen
K
K
Sokoll
M D
MD
D000109:Acetylcholine / Q000378:metabolism; D000375:Aging / Q000502:physiology*; D000818:Animals; D004594:Electrophysiology; D005071:Evoked Potentials / Q000187:drug effects; D006221:Halothane / Q000494:pharmacology*; D007478:Iontophoresis; D008297:Male; D008839:Microelectrodes; D009469:Neuromuscular Junction / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013569:Synapses / Q000187:drug effects / Q000502:physiology; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology*
D000109:Acetylcholine; D006221:Halothane