Figure 4. The effects of tetrodotoxin (TTX), atropine, and nifedipine on gastrin-releasing peptide (GRP)-induced LES sling muscle contractions and the effects of ω-conotoxin GVIA (CTX) and tetrodotoxin (TTX) on LES sling muscle contractions induced by [D-Tyr6,Apa-4Cl11,Phe13,Nle14]bombesin-(6-14) (DTACPN-BN).
(A) TTX (1 μM) and atropine (1 μM) had no significant effects on LES sling muscle strip contractions that were induced by GRP. In contrast, nifedipine (1 μM) had a significant inhibitory effect on LES sling muscle strip contractions that were induced by GRP. *Represents significant differences compared with GRP alone (p < 0.05). (B) Both CTX and TTX significantly (p < 0.05) inhibited the DTACPN-BN-induced porcine LES sling muscle fiber contractions. *Significantly different from DTACPN-BN alone (p < 0.05).