S-Space College of Medicine/School of Medicine (의과대학/대학원) Dept. of Medicine (의학과) The Seoul Journal of Medicine The Seoul Journal of Medicine Vol. 35 No.1 (1994)
The Possible Role of Nitric Oxide on Enteric Nerves-Mediated Relaxation of the Gastric Smooth Muscle of the Guinea Pig
- Ahn, Jung Mo; Ahn, Seung Cheol; Choi, Youn Baik; Kang, Tong Mook; Kim, Sung Joon; So, Insuk; Kim, Ki Whan
- Issue Date
- Seoul J Med, Vol.35 No.1, pp. 1-8
- EFS; Lⁿ-Nitro-L-arginine; Nitric oxide; L-Arg; Nonadrenergic noncholinergic; Inhibitory junction potential
- The influence of the enteric nerves stimulation on the contractility of gastric
circular muscle was studied in guinea pig stomachs. The enteric nerves were
activated by electric field stimulation(EFS; 90 V, 1 rns, 32 Hz square pulses for 1 s),
EFS produced initial transient contraction followed by relaxation and slow recovery.
The initial contraction was sensitively blocked by treatment with atropine. The following
relaxation still occurred in nonadrenergic noncholinergidNANC) state. EFSinduced
relaxation was reduced by LG-nitro-L-arginine(L-NNA), a nitric oxide(NO)
synthase inhibitor. The relaxation was restored from the suppressed state after the application
of L-arginine(L-arg), a substrate of nitric oxide synthase. With conventional intracellular
recording, slow wave and inhibitory junction potential(IJP) were recorded.
L-NNA had no effect on IJP, while apamin blocked it. In conclusion, it is suggested
that NO may playa major role in EFS-induced relaxation. The exact mechanism of
this relaxation is unknown, but the relaxation does not result from the IJP induced by
the activation of apamin-sensitive potassium channels.