Figure 9.

Effects of L-methionine on lower oesophageal sphincter (LOS) basal tone (A) and of nerve-mediated relaxation (B) in opossum LOS. L-methionine significantly increased basal tone but did not inhibit LOS relaxation induced by electrical field stimulation. Subsequent application of N-nitro-L-arginine methyl ester (L-NAME) abolished LOS relaxation and unmasked a contraction. L-NAME also inhibited the spontaneous fluctuations in the basal LOS tone. The arrow in (A) represents the time of application of L-methionine. The arrows in (B) represent the onset of electrical field stimulation. These results are consistent with the electrophysiological data obtained in murine LOS.