Effect of Growth on the Concentration of L-Histidine and Anserine in the White Muscle of Carp and Rainbow Trout

Abstract

Accumulation patterns of L-histidine and related dipeptides were examined in carp and rainbow trout white muscle as a function of body weight.
Young carp (n=30) increased their body mass from 1.8 to over 200g during the growth period of a year. White muscle free L-histidine increased almost in a linear fashion from about 5 to 20μmol/g wet weight over the body weight range of 1.8 to 30-40g. Then the level of L-histidine decreased slightly to reach an almost constant level at 14.5-18.6μmol/g wet weight over the remaining growth period. On a double logarithmic plot, this histidine increase was linear related to body weight for small carp weighing below 32g (n=16, slope=0.52, r=0.88, p<0.001) and almost zero for larger cazp weighing from 15 to 247g (n=21, slope=-0.06, r=-0.28).
In rainbow trout weighing from 1.8 to 321g (n=77), the Canadian trout weighing 10-150g (n=29) exhibited significantly higher amount of anserine in white muscle than their Japanese counterpart (n=48) over the same weight range. Both trouts, however, showed almost the same hyperbolic pattern of anserine increase over the concentration range of 3 to 18μmol/g wet weight. This increase was linear in double logarithmic scale for both Canadian and Japanese trout (slope=0.32, r=0.91, p<0.001 for Japanese trout; slope=0.15, r=0.82, p<0.001 for Canadian trout).