The role of cGMP-dependent signaling pathway in synaptic vesicle cycle at the frog motor nerve terminals.
The role of cGMP-dependent pathways in synaptic vesicle recycling in motor nerve endings during prolonged high-frequency stimulation was studied at frog neuromuscular junctions using electrophysiological and fluorescent methods. An increase of intracellular cGMP concentration (8-Br-cGMP or 8-pCPT-cGMP) significantly reduced the cycle time for synaptic vesicles through the enhancement of vesicular traffic rate from the recycling pool to the readily releasable pool and acceleration of fast endocytosis. Pharmacological inhibition of soluble guanylate cyclase or protein kinase G slowed down the rate of recycling as well as endocytosis of synaptic vesicles. The results suggest that cGMP-PKG-dependent pathway serves a significant function in the control of vesicular cycle in frog motor terminals.
Petrov
Aleksej M
AM
Department of Normal Physiology, Kazan State Medical University, Kazan, Russia. fysio@rambler.ru
Giniatullin
Arthur R
AR
Sitdikova
Guzel F
GF
Zefirov
Andrej L
AL
D000818:Animals; D006152:Cyclic GMP / Q000378:metabolism*; D017869:Cyclic GMP-Dependent Protein Kinases / Q000378:metabolism; D004705:Endocytosis / Q000502:physiology; D005456:Fluorescent Dyes; D006162:Guanylate Cyclase / Q000378:metabolism; D008856:Microscopy, Fluorescence; D009046:Motor Neurons / Q000378:metabolism* / Q000648:ultrastructure; D009469:Neuromuscular Junction / Q000378:metabolism* / Q000648:ultrastructure; D018408:Patch-Clamp Techniques; D017729:Presynaptic Terminals / Q000378:metabolism* / Q000648:ultrastructure; D011726:Pyridinium Compounds; D000644:Quaternary Ammonium Compounds; D011895:Rana ridibunda; D015398:Signal Transduction / Q000502:physiology; D013570:Synaptic Membranes / Q000378:metabolism / Q000648:ultrastructure; D055366:Synaptic Potentials / Q000502:physiology; D009435:Synaptic Transmission / Q000502:physiology*; D013572:Synaptic Vesicles / Q000378:metabolism* / Q000648:ultrastructure
C073804:FM1 43; D005456:Fluorescent Dyes; D011726:Pyridinium Compounds; D000644:Quaternary Ammonium Compounds; D017869:Cyclic GMP-Dependent Protein Kinases; D006162:Guanylate Cyclase; D006152:Cyclic GMP