RT Journal Article
SR Electronic
T1 Uptake and Metabolism of L-Alanine by Freshly Isolated Trout (<em>Salmo Trutta</em>) Hepatocytes: The Effect of Fasting
JF Journal of Experimental Biology
JO J. Exp. Biol.
FD The Company of Biologists Ltd
SP 37
OP 52
VO 169
IS 1
A1 CANALS, P.
A1 GALLARDO, M. A.
A1 BLASCO, J.
A1 SÁNCHEZ, J.
YR 1992
UL http://jeb.biologists.org/content/169/1/37.abstract
AB Uptake and metabolism of L-alanine by freshly isolated trout hepatocytes has been analyzed. This amino acid is incorporated ‘uphill’ by different carriers, either Na+-dependent or Na+-independent. Na+-dependent uptake shows the characteristics of an ASC system on the basis of cation dependence and substrate preferences. The Na+-independent uptake is split between an L-cysteine-sensitive system and a non-saturable component. No uptake through system A has been found, suggesting that this carrier is lacking in trout hepatocytes. On the basis of inhibition by several preferred amino acids, L-alanine is not taken up through either the L or N systems.Fasting induced changes in both the uptake of L-alanine and its metabolism to CO2 and glucose. There was an increase in uptake that showed an inverse relationship with L-alanine plasma levels. Glucose production from L-alanine rose during food deprivation, while CO2 production showed an initial increase, similar to that of glucose. At the end of the fasting time considered, however, there was a drop in CO2 production, indicating a different kind of regulation for alanine oxidation and gluconeogenesis.Note: To whom reprint requests should be sent.