Enriched protein diet-modified ghrelin expression and secretion in rats.
Gastrointestinal (GI) integrity and function are regulated by nutrition and growth factors. The discovery of ghrelin, a natural growth hormone (GH) secretagogue produced by the gastrointestinal (GI) tract, is a potential link between diet and growth signals. The aim of this study was to evaluate macronutrient effect on ghrelin expression and secretion in addition to some possible function in intestinal trophic status. Wistar rats were fed a high-carbohydrate, high-protein (HP), high-fat or standard (St) diet. Animals received the same daily food volume and caloric intake. After 7 days, animals were fasted for 24 h and blood and tissue samples were obtained just before feeding or at 2 or 6 h after feeding. Fasting high-protein-fed rats had higher ghrelin plasma levels than with rats fed the high-carbohydrate, high-fat or standard diets. Two-hours after refeeding, ghrelin plasma levels had decreased in all groups with a slight recovery at 6 h after refeeding, except in the high-protein group. Ghrelin plasma levels in rats fed with the high-protein diet correlated negatively with their GH and insulin-like growth factor 1 (IGF-1) plasma concentrations which were also the lowest among the study groups. In conclusion, ghrelin secretion was nutritionally manipulated because a protein-enriched diet increased its levels.
Vallejo-Cremades
M T
MT
Research Unit, Servicio de Cirugía Experimental, Hospital Universitario La Paz, Paseo de la Castellana 261, 28046 Madrid, Spain.
Gómez-García
L
L
Chacatas-Cortesao
M
M
Moreno
C
C
Sánchez
M
M
De Miguel
E
E
Gómez De Segura
I A
IA
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D004044:Dietary Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D004386:Duodenum / Q000033:anatomy & histology / Q000187:drug effects / Q000254:growth & development; D005215:Fasting; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects*; D054439:Ghrelin; D013006:Growth Hormone / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D007583:Jejunum / Q000033:anatomy & histology / Q000187:drug effects / Q000254:growth & development; D036361:Peptide Hormones / Q000096:biosynthesis* / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats
D004044:Dietary Proteins; D054439:Ghrelin; D036361:Peptide Hormones; D012333:RNA, Messenger; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone