Peptides that regulate food intake: somatostatin alters intake of amino acid-imbalanced diets and taste buds of tongue in rats.
The present studies were designed to evaluate a potential dose-dependent effect of somatostatin (SRIF) administered peripherally on intake of either a low-protein basal diet or threonine-imbalanced diet (THR-IMB), on body weight gain (DeltaBW), gut motility, and on the histology of taste buds in rats. SRIF administration had a dual effect related to its concentration, increasing the intake of THR-IMB diet at low concentration and decreasing THR-IMB diet at high concentration. During the light phase, SRIF treatment increased the intake of THR-IMB diet, suggesting that the usual anorectic effect induced by intake of THR-IMB diet was attenuated. High-dosage SRIF decreases gastrointestinal motility, which, in turn, can decrease food intake and DeltaBW. The combination of THR-IMB diet regimen and SRIF treatment also induced significant modifications on the taste buds of the tongue. The feeding response to an amino acid-imbalanced diet includes a learned aversion to the diet, and animals may use taste in establishing that aversion. Modifications of taste buds of SRIF-treated rats eating THR-IMB diet might explain the increase of imbalanced diet intake if treated rats perceive this food as less aversive.
Dipartimento di Scienze Biomediche, Sezione di Fisiologia, Università di Modena e Reggio Emilia, 41100 Modena, Italy. scalera@unimore.it
Giuseppe
G
Scalera
D000596:Amino Acids / Q000008:administration & dosage*; D000821:Animal Feed; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D018753:Diet, Protein-Restricted; D004305:Dose-Response Relationship, Drug; D005247:Feeding Behavior / Q000187:drug effects / Q000502:physiology; D005769:Gastrointestinal Motility / Q000187:drug effects; D008027:Light; D051381:Rats; D013004:Somatostatin / Q000494:pharmacology*; D013650:Taste Buds / Q000187:drug effects* / Q000502:physiology; D013912:Threonine / Q000008:administration & dosage
D000596:Amino Acids; D013912:Threonine; D013004:Somatostatin