Comparative stimulation of motilin duodenal receptor by porcine or canine motilin.

摘要: Abstract Motilins purified from porcine and canine intestine differ in their amino acid composition positions 7-8-12-13-14. We studied vitro the contractile response of longitudinal duodenal muscles various animals (guinea pig, rabbit, dog) to synthetic motilins. Both substances failed elicit contraction guinea pig duodenum but were active equally potent on rabbit muscle. In dogs, motilin was inactive at concentrations tested (up 10 −4 M) whereas induced contractions a doseresponse fashion (mean dose required induce half-maximal response: 4.82 ± 0.25 × −5 M). The generated by (10 not influenced atropine, hexamethonium, tetrodotoxin, naloxone, or sodium nitroprusside (all used blocked verapamil ). Our study (a) shows that species-related structural alterations molecules generate different bioactive capacities some animal species, (b) suggests middle portion molecule is important for its expression, (c) presence receptors muscle, (d) an influx extracellular calcium involved muscle elicited motilin.