Zeitschrift für Ernährung und Lebensmittelwissenschaften
Offener Zugang

Abstrakt

Nutritional Recovery and its Effect on Tryptophan-5-Hydroxylases Expression, Cell Number and on Changes Caused by Intrauterine Growth Restriction in the Developing Brain

Gabriel Manjarrez-Gutierrez*, Jorge Hernandez-Rodriguez, Jose Antonio Mondragon-Herrera

Objective: The aim of this work was to determine whether the changes in tryptophan-5-hydroxylase (TPH) 1 or 2 brain expression caused by intrauterine growth restriction (IUGR) are maintained or return to normal in the nutritionally-recovered undernourished offspring (UNDO) of rats.

Methods: The experimental procedure was: Wistar female rats were subjected to a protein-caloric-restricted diet during gestation. At birth, part of the newborn UNDO pups were fed by their own mothers (UNDO Group), and others were fed by normal control mothers to allow their nutritional recovery (NR Group); pups from normal control dams were fed by them (C Group). On days 1, 15 and 21, brainstem tissue, at the level of dorsal raphe nucleus (DRN), was obtained, in order to determine L-tryptophan (L-Trp), serotonin (5-HT) and TPH activity. In addition, TPH 1 or 2 expressions were determined using specific monoclonal antibodies by Western blot and by immunohistochemistry in neurons.

Results: In the UNDO group, an increase in L-Trp, 5-HT and TPH activity was confirmed. Both TPH isoforms were expressed since birth, with TPH1 expression being higher in the UNDO group. TPH2 activity was also elevated but was lower activity in comparison with controls. The NR group was able to physically recover to normality, but their neurochemical changes and elevated number of TPH1 neurons remained unchanged and did not return to control values. TPH2 neuronal number did return to normal control values.

Discussion: These results strongly suggest that the changes in the UNDO group may explain, together with a possible important Pet-1 molecular system participation, the chronic activation of the brain serotonin system in subjects that suffered IUGR due to undernourishment.