Effect of galanin on isolated strips of smooth muscle from the gastrointestinal tract of chickens

The contractile effects of galanin on isolated longitudinal smooth muscle strips of pre‐crop esophagus, proventriculus, duodenum, colon, and cecum of chickens were investigated. Application of galanin (5.0–100.0 nM) evoked strong contractions from the colon and cecum (hindgut), but evoked minimal responses from the pre‐crop esophagus, proventriculus, and duodenum (foregut). Previous studies have demonstrated that the central administration of galanin stimulates food consumption in rats. Since galanin‐like immunoreactivity is present in the chicken brain, we speculate that the central release of galanin may increase food intake and possibly be involved in a hypothalamic‐colonic reflex modulating hindgut motility and generating a defecation. Thus, the results of this study demonstrate the presence of galanin receptors in the chicken gut and suggest a possible link with their functional presence in the hindgut to the chicken central nervous system. J. Exp. Zool. 283:463–468, 1999. © 1999 Wiley‐Liss, Inc.