Project 1.5

Intestinal absorption and systemic effects of myo-inositol in laying hens

Korinna Huber / Markus Rodehutscord

Myo-inositol (MI) is the end product of complete dephosphorylation of phytate by endogenous phytases and phosphatases in the gastrointestinal tract of laying hens with an efficient phosphorus utilization. MI is known to be a component of cell membranes and of intracellular phosphoinositide- and inositolphosphate-dependent signaling pathways. Thereby, it is an important key molecule in healthy function of body cells. However, its role in laying hens is not well known yet.

The aim of this study is to assess the intestinal MI transport mechanisms, its body-own metabolism and its association with the plasma metabolome. Expression of intestinal MI transporters will be examined and correlated to functional measures of MI transport in Ussing chambers (Project 1.6). Furthermore, enzymes involved in MI synthesis and degradation will be quantified in several tissues. The metabolic profile of laying hens as influenced by age and feeding will be assessed by a targeted metabolomics approach to identify associations between this profile, MI metabolism and metabolic health. All data will be used for an integrative bioinformatic analysis.

Results

To identify novel pathways of importance for individual adaptation to a metabolic challenge such as egg production in laying hens, myo-inositol (MI) metabolism and plasma metabolite profiles during the productive lifespan were examined in two genetically different strains, Lohmann Brown-Classic (LB) and LSL-Classic (LSL) hens in the study of Gonzalez-Uarquin et al. 2021. They were housed during the productive lifespan and sampled at 10, 16, 24, 30 and 60 weeks of age. The targeted AbsoluteIDQ p180 Kit was used for metabolite profiling in plasma whereas a MI enzymatic kit and ELISAs were used to quantify tissue MI concentrations and MI key enzymes (IMPase 1 and MIOX), respectively. As major finding, kidney MIOX was differently expressed in LB and LSL hens with higher amounts in LB. The onset of egg laying between week 16 and 24 of life span was associated with a clear change in the metabolite profiles, however LSL hens and LB hens adapt differently. Pearson’s correlation analyses over all hens at all time points indicated that higher expression of MI degrading enzyme MIOX was related to markers indicating metabolic stress.

Concentrations of myo-inositol oxygenase (MIOX) in kidneys of LB (olive) and LSL (navy) hens at five productive periods. Symbols show mean ± SEM (n = 10 hens per strain and period). Two-way ANOVA followed by the post-hoc test Tukey HSD (Honestly Significant Difference) were used for statistical analysis.
Different letters indicate significant differences within strain at different productive periods (p < 0.05) whereas ** indicate highly significant differences (p < 0.01) between strains at the same productive period. F-values showed the ratio of between-groups to within-groups variances.
Strain: F= 16.32; P<0.001
Period: F= 28.67; P<0.001
Interaction: F= 10.44; P<0.001
Project leaders

Prof. Dr. Korinna Huber
Institut für Nutztierwissenschaften, Fachgebiet für Funktionelle Anatomie der Nutztiere
+49 711 459 23998
E-mail

Prof. Dr. Markus Rodehutscord
Institut für Nutztierwissenschaften, Fachgebiet für Tierernährung
+49 711 459 22420
E-mail

Staff

Fernando Gonzalez Uarquin
Institut für Nutztierwissenschaften, Fachgebiet für Funktionelle Anatomie der Nutztiere
+49 711 459 23307
E-mail

Projects