Effect of dietary supplementation with different levels of inulin-type fructans on renal expression of aquaporin 2 of growing piglets

Authors: KATARZYNA MICHALEK, MARTA GRABOWSKA, MARIUSZ SKOWRONSKI, ADAM LEPCZYNSKI, AGNIESZKA HEROSIMCZYK, MARIA LASZCZYNSKA

Abstract: The purpose of this study was to identify and investigate the expression of aquaporin 2 (AQP2) in the renal tubules of growing piglets fed with different levels of inulin-type fructans. The experiment was performed on five groups of PIC x Penarlan P76 crossbred piglets fed with the following diets: standard diet (control group) and standard diet supplemented with 1% (group I), 2% (group II), and 3% (group III) of water extract of chicory root inulin-type fructans. The animals from the group IV were fed with standard diet supplemented with 4% dried chicory roots. To analyze immunolocalization and expression of AQP2 in the renal tubules we used immunohistochemistry and western blotting. We demonstrated that AQP2 in growing piglets is mainly located in the apical plasma membrane, but also in the intracellular components as well as the basolateral membrane of the principal cells of the collecting ducts. Furthermore, we found that the feeding of growing piglets with diets supplemented with different amounts of inulin-type fructans statistically significantly increased the total amount of AQP2 and increased expression of this protein in the apical plasma membrane. These changes seem to be proportional to the dose of inulin-type fructans in the diet.

Keywords: Aquaporin 2, renal tubule, diet, inulin, growing piglets

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