L-ethionine, an amino acid analogue, stimulates eating in rats.
The fructose analogue 2,5-anhydro-D-mannitol (2,5-AM) triggers feeding in rats through its actions in liver, which include a decrease in ATP due to trapping of phosphate. To determine whether decreasing liver ATP by a different means would also trigger feeding, we gave rats L-ethionine (ETH), an amino acid analogue that reduces ATP in liver by trapping adenosine as S-adenosyl-L-ethionine. ETH-treatment increased food intake from 4 to 8 h after administration, without affecting 24-h intake. Two hours after treatment, liver ATP was 25% lower in rats given ETH than in vehicle-treated controls. Circulating fuels and liver lactate and pyruvate were not affected by ETH treatment, whereas liver glycogen was 15% lower in ETH-treated rats. These results are the first to show that an amino acid analogue elicits feeding in rats fed protein-sufficient diets. Because a decrease in liver ATP is the only common effect of ETH and 2,5-AM observed thus far, a signal related to liver ATP status may be involved in the mechanism for initiation of feeding in rats.
Rawson
N E
NE
Monell Chemical Senses Center, Philadelphia, Pennsylvania 19104.
Ulrich
P M
PM
Friedman
M I
MI
D000596:Amino Acids / Q000494:pharmacology; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D004041:Dietary Fats / Q000008:administration & dosage; D004435:Eating / Q000187:drug effects*; D005001:Ethionine / Q000494:pharmacology*; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051381:Rats
D000596:Amino Acids; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D005001:Ethionine