Identification of leucomyosuppressin in the German cockroach, Blattella germanica, as an inhibitor of food intake.
The feeding pattern of the adult female of Blattella germanica peaks in the middle of the vitellogenic cycle. Following the hypothesis that a factor inhibiting gut peristalsis also inhibits food intake and is involved in the regulation of feeding, we searched for the most powerful myoinhibitory peptide in brain extracts from B. germanica females collected after the peak within the feeding cycle. Through HPLC purification and sequence analysis, we obtained the peptide leucomyosuppressin (LMS): pQDVDHVFLRFamide. LMS elicited a powerful myoinhibitory effect on B. germanica foregut and hindgut, with ED(50) values around 10(-10) M. In addition, it inhibited food intake in vivo in a dose-dependent manner at doses between 5 and 50 microg. The study of the distribution of ingested food in the foregut, midgut and hindgut of B. germanica females treated with LMS showed that food accumulates in the foregut, which may be due to the myoinhibitory effects of the peptide. We propose that this accumulation inhibits food intake because of the persistence of the signals from gut stretch receptors.
Aguilar
Ruth
R
Department of Physiology and Molecular Biodiversity, Institut de Biologia Molecular de Barcelona (CSIC), Jordi Girona 18, 08034 Barcelona, Spain.
Maestro
José L
JL
Vilaplana
Lluïsa
L
Chiva
Cristina
C
Andreu
David
D
Bellés
Xavier
X
D000818:Animals; D001522:Behavior, Animal; D001681:Biological Assay; D020048:Blattellidae; D001921:Brain / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D019835:FMRFamide; D005247:Feeding Behavior; D005260:Female; D013058:Mass Spectrometry; D009479:Neuropeptides / Q000096:biosynthesis* / Q000737:chemistry; D010455:Peptides / Q000737:chemistry; D011761:Pyrrolidonecarboxylic Acid / Q000737:chemistry; D013997:Time Factors
D009479:Neuropeptides; D010455:Peptides; C058650:leucomyosuppressin; D019835:FMRFamide; D011761:Pyrrolidonecarboxylic Acid