Effects of temperature on L-leucine transport in toadfish liver in vivo.
The effect of body temperature in the 4--30 degrees C range on L-leucine uptake by toadfish liver in vivo was examined by means of a single-injection pulse technique. The ratio of [14C]leucine to [3H]mannitol or [3H]inulin in blood leaving the liver was measured as a function of time after hepatic portal vein injection. Recoveries of the two isotopes in liver and [14C]leucine incorporation into protein were determined. The Q10 value for influx was 3.8, that for efflux 2.8. At all temperatures, the leucine influx was 8--10-times higher than its incorporation into protein. The directly energy-linked reactions appear to be the main site of increased temperature sensitivity at low temperatures.
D000818:Animals; D001693:Biological Transport, Active; D001831:Body Temperature; D005399:Fishes / Q000378:metabolism*; D007700:Kinetics; D007930:Leucine / Q000097:blood / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*
D007930:Leucine