Effect of food deprivation and refeeding on vasotocin and isotocin receptor genes expression in the gilthead sea bream (Sparus aurata)

Abstract

The present study describes the influence of the starvation and re-feeding processes on the vasotocinergic and isotocinergic systems in Sparus aurata. mRNA expression levels for vasotocin (AVT) and isotocin (IT) receptor genes were assessed in a time-course response study in immature gilthead sea bream (Sparus aurata) maintained under food deprivation during 14 days as well as after one week of re-feeding. Changes in plasma cortisol and metabolites levels, as well as hepatosomatic index, indicate a clear stress situation and metabolic mobilization in fasted and re-feeded specimens. At hypothalamic level, mRNA expression of both AVTR V1a2-type and V2-type 216peaked in the first 7 days in those specimens exposed to starving, decreasing onwards till the end of the experiment. In liver, AVTR V1a2-type expression levels were similar between re-feeding and food-deprived groups. Metabolic indicators assessed shown that sea breams maintained under re-feeding conditions recovery its valuesnear to those found in the control group. Our results suggest a clear interaction between stress and vasotocinergic/isotocinergic systems during the early phase of adaptation to food deprivation and re-feeding process.