The role of propionate and acetate in the control of food intake in sheep.
Sheep fed ad lib. on a good-quality pelleted diet (g/kg; hay 500, barley 300, molasses, fish meal and minerals) were infused via the hepatic portal vein with mixtures of the sodium salts of volatile fatty acids, acetate and propionate, and a variety of equivalent osmotic loads. Propionate infused at rates between 0.6 and 2.5 mmol/min consistently reduced food intake in a linear, dose-related manner. Propionate infusions resulted in consistent dose-related increases in peripheral venous plasma glucose concentration but variable changes in insulin concentration. Infusion of osmotically balanced mixtures of propionate, acetate, mannitol or saline (9 g NaCl/l) indicated that at constant osmotic loading propionate caused a greater reduction in intake than other infusions. Acetate infusions only depressed food intake when administered as a 1 M solution. Lower concentrations had little effect, similar to that of equivalent osmotic loads of mannitol or saline. It is concluded that portal propionate flow has a potential role in the control of food intake in ruminants which is independent of osmotic effects or changes in plasma insulin concentration.
Farningham
D A
DA
Rowett Research Institute, Bucksburn, Aberdeen.
Whyte
C C
CC
D000085:Acetates / Q000494:pharmacology*; D019342:Acetic Acid; D000818:Animals; D001786:Blood Glucose / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects*; D005260:Female; D007262:Infusions, Intravenous; D007328:Insulin / Q000097:blood; D011169:Portal Vein; D011422:Propionates / Q000494:pharmacology*; D012756:Sheep / Q000502:physiology*
D000085:Acetates; D001786:Blood Glucose; D007328:Insulin; D011422:Propionates; C029658:propionic acid; D019342:Acetic Acid