The effect of 3,3-dipyridylmethyl-1-phenyl-2-indolinone on the neuromuscular transmission in the rodent skeletal muscles.
The effects of a cognition enhancer, 3,3-dipyridylmethyl-1-phenyl-2-indolinone (DPMPI) (21.5-645 microM), on neuromuscular transmission were studied electrophysiologically on diaphragms of mouse and rat and the soleus muscle of rat. The drug DPMPI (21.5-645 microM) increased both direct and indirect twitch tension of mouse diaphragm. It also increased (a) the frequency of miniature endplate potentials and (b) the quantal content of endplate potential. However, DPMPI (64.5 microM) affected neither the amplitude of the directly elicited action potential of soleus muscle in the rat nor the magnitude of the resting membrane potential of mouse diaphragm, although DPMPI (215 microM) decreased the amplitude of the compound action potential of phrenic nerve. Based on these results, it is concluded that DPMPI had several effects on neuromuscular transmission, i.e. it (a) facilitated the transmitter releasing process of the motor nerve terminal, (b) decreased the conduction in the phrenic nerve and (c) increased the directly elicited twitch tension.
Tsai
M C
MC
Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Republic of China.
Su
J L
JL
Chen
M L
ML
Fan
S Z
SZ
Cheng
C Y
CY
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D004594:Electrophysiology; D005260:Female; D007211:Indoles / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009045:Motor Endplate / Q000187:drug effects; D009132:Muscles / Q000187:drug effects / Q000294:innervation*; D009469:Neuromuscular Junction / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D010791:Phrenic Nerve / Q000187:drug effects; D011725:Pyridines / Q000494:pharmacology*; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology*
D007211:Indoles; D011725:Pyridines; C061017:linopirdine