TY - JOUR
T1 - Effects of acute and chronic level of protein supply on metabolic leucine utilization in growing and mature rats
AU - Weijs, Peter
N1 - <html><body>
<p>Weijs, P. J. M., Schreurs, V. V., Koopmanschap, R. E., Grooten, H. N.,
Schoonman, A. T., Boekholt, H. A. 'Effects of acute and chronic level of protein
supply on metabolic leucine utilization in growing and mature rats'. In: Br J
Nutr 1993 Jul;70(1):117-25.</p>
</body></html>
PY - 1993/7/1
Y1 - 1993/7/1
N2 - Abstract:
Effects of acute (meal) and chronic (diet) level of protein supply on metabolic leucine utilization were investigated in growing (10 weeks) and mature (> 1 year) rats. Rats were conditioned on a high-protein (HP) diet (210 g casein/kg feed) or a low-protein (LP) diet (75 g casein/kg feed) from 7 weeks of age. Overnight-fasted rats were offered a HP or LP meal during a 8 h 14CO2 breath test with a constant infusion of either L-[1-14C]leucine (carboxyl, CL) or L-[U-14C]leucine (universal, UL). Before the meal 14CO2 output was lower for overnight-fasted rats fed on LP than on HP (P <0.001), and also lower for growing than for mature rats (P <0.001). Meal ingestion resulted in a rapid increase in 14CO2 output. From 2 h after the start of the meal the effect of acute protein supply on 14CO2 output was significant (P <0.001), while the effect of chronic protein supply disappeared for CL. After the meal 14CO2 output was transiently lower for growing than for mature rats (P <0.05), especially after the LP meal. The difference in 14CO2 output between CL and UL increased transiently after the meal, indicating an increase in decarboxylation relative to total oxidation of leucine.
AB - Abstract:
Effects of acute (meal) and chronic (diet) level of protein supply on metabolic leucine utilization were investigated in growing (10 weeks) and mature (> 1 year) rats. Rats were conditioned on a high-protein (HP) diet (210 g casein/kg feed) or a low-protein (LP) diet (75 g casein/kg feed) from 7 weeks of age. Overnight-fasted rats were offered a HP or LP meal during a 8 h 14CO2 breath test with a constant infusion of either L-[1-14C]leucine (carboxyl, CL) or L-[U-14C]leucine (universal, UL). Before the meal 14CO2 output was lower for overnight-fasted rats fed on LP than on HP (P <0.001), and also lower for growing than for mature rats (P <0.001). Meal ingestion resulted in a rapid increase in 14CO2 output. From 2 h after the start of the meal the effect of acute protein supply on 14CO2 output was significant (P <0.001), while the effect of chronic protein supply disappeared for CL. After the meal 14CO2 output was transiently lower for growing than for mature rats (P <0.05), especially after the LP meal. The difference in 14CO2 output between CL and UL increased transiently after the meal, indicating an increase in decarboxylation relative to total oxidation of leucine.
U2 - https://doi.org/10.1079/BJN19930109
DO - https://doi.org/10.1079/BJN19930109
M3 - Article
SN - 1475-2662
JO - BJN: British Journal of Nutrition
JF - BJN: British Journal of Nutrition
ER -