Nitric oxide is a neuromodulator in cat pancreatic ganglia: histochemical and electrophysiological study.
This study examined the distribution of NADPH-diaphorase (NADPH-d) activity in cat pancreatic ganglia and the electrophysiological effects of nitric oxide (NO) donors, NO and the effect of endogenously released NO. The majority (64%) of pancreatic ganglion neurons stained positive for NADPH-d. Large nerve trunks contained numerous non-varicose NADPH-d positive fibers. NADPH-d positive nerve fibers within individual ganglia were varicosed. L-Arginine, sodium nitroprusside and NO, applied in the vicinity of the impaled neuron, evoked a hyperpolarizing response and initiated fast excitatory postsynaptic potentials (EPSPs) in the majority of neurons tested. The hyperpolarizing response was not affected by low Ca2+ (0.1 mM), high Mg2+ (15 mM). Pretreatment with nitro-L-arginine increased the amplitude of slow EPSPs in about 50% of neurons tested. These results support the hypothesis that NO plays a role in ganglionic transmission in the cat pancreas.
Sha
L
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Department of Physiology and Biophysics, Mayo Clinic, Rochester, MN 55905, USA.
Miller
S M
SM
Szurszewski
J H
JH
D000818:Animals; D001120:Arginine / Q000494:pharmacology; D002415:Cats; D004558:Electric Stimulation; D004594:Electrophysiology; D005260:Female; D005724:Ganglia / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D006651:Histocytochemistry; D008297:Male; D009252:NADPH Dehydrogenase / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D018377:Neurotransmitter Agents / Q000494:pharmacology*; D009569:Nitric Oxide / Q000494:pharmacology*; D009599:Nitroprusside / Q000494:pharmacology; D010179:Pancreas / Q000294:innervation*
D018377:Neurotransmitter Agents; D009599:Nitroprusside; D009569:Nitric Oxide; D001120:Arginine; D009252:NADPH Dehydrogenase