EFFECTS OF 5-HDLTP ON DIETARY SELF-SELECT ION IN OVEREATING RATS

Recent research has suggested that self-selection of carbohydrates in rats may be mediated by serotonin (5-HTP). Since drugs enhancing serot onergic transmission reduce carbohydrate selection by sparing proteins , a mechanism depending on brain serotonin levels has been suggested t o control carbohydrate intake. In this study the precursor of serotoni n 5-hydroxytryptophan (5-HTP) was injected (i.p) to overeating rats de pending on 5-HTP, who were offered separate sources of nutriments to s ee if the mechanism also acted with animals on overeat regime. Animals selected the expected amounts of either nutriment in the overeat regi me. When 5-HTP was injected, a significant decrease in the self-select ion of carbohydrate was observed and the protein sparing effect was no t found. Results of the present study agree with previous data suggest ing that carbohydrate self-selection is mediated by serotonin.