The effect of supplemental propionate on insulin responsiveness to glucose and tissue responsiveness to insulin in relation to feeding in sheep

Two glucose clamp techniques were performed for 6 h starting 2 h before the initi- ation of feeding to investigate the effect of dietary propionate supplementation on insulin responsiveness to glucose and tissue responsiveness to insulin in relation to feeding in rams. The rams were fed alfalfa hay without (Cont diet) and with 10 mmol.kg BW-1 .d-1 of calcium propionate (Prop diet) for 4 weeks in randomized order. With the hyperglycemic clamp, the ratio of plasma insulin increment to glucose infusion rate did not differ between the diets, but for the Prop diet the ratio was less during the pre-feeding period. With the hyperinsulinemic euglycemic clamp, the glucose infusion rate was lower (P < 0.05) for the Prop diet than the Cont diet, and increased (P < 0.05) after feeding. In rams supplemented propionate tissue responsiveness to insulin was reduced. Propionate supplementation may either impair glucose utilization in response to insulin infusion or enhance glucose production from propionate. @ Inra/Elsevier, Paris insulin / glucose clamp / propionate / feeding / sheep Rsum -Effet d'un supplment de propianate sur la rponse insulinique au glucose et sur la raction tissulaire l'insuline en rapport avec la prise alimentaire chez le mouton. Deux techniques de clamp glycmique ont t utilises pendant 6 h, partir de 2 h avant le dbut de la prise d'aliments pour tudier l'effet d'un supplment alimentaire de propionate sur la raction insu- linique et la raction tissulaire l'insuline en rapport avec l'alimentation chez des bliers. Les ani- maux taient nourris avec du foin de luzerne sans (rgime Cont) et avec (rgime Prop) 10 mmol.kgPV-1 .rl de propionate de calcium pendant 4 semaines dans un ordre alatoire. Avec le clamp hyperglycmique, le rapport de l'argumentation de l'insuline plasmatique au taux d'infu- sion de glucose ne diffrait pas entre les rgimes, mais pour le rgime Prop, le rapport tait plus