The Effects Of Anti‐Fibroblast Growth Factor 23‐Peptides Antibodies On Excreta Phosphate Of Chicks

Abstract

Neutralizing antibodies against fibroblast growth factor 23 (FGF23) have been previously shown to reduce the phosphate excretion of mice, rat and human. The objective of the present study was to determine the effect of passively transferred anti‐FGF23 peptides (FGF23‐3, VFFPGMNP; FGF23‐T, HRNTRSAD) antibodies on excreta phosphate content of chicks. Hens were vaccinated with a control vaccine or synthetic peptide vaccines, and eggs were collected and incubated following the peak antibody titer. Progeny chicks from each vaccine treatment were divided into 6 pens and fed a diet with either 0.13 or 0.36% available phosphate (n=3 pens per diet). After two weeks, all chicks were bled (to determine plasma phosphorus), and the total excreta from each pen were collected (for the analysis of phosphate content). Plasma phosphate and excreta phosphate were reduced in chicks fed 0.13% versus 0.36% phosphate (main effect of dietary phosphate, p<0.01). Interestingly, anti‐FGF antibodies significantly increased plasma phosphate of chicks (main effect of anti‐FGF23 antibodies, p<0.01). When compared with the control vaccine, chicks with anti‐FGF3 and anti‐FGFT antibodies showed 24.77% and 22.94% decrease, respectively in excreta phosphate in low phosphate diet; and 27.46% and 23.94% decrease, respectively in excreta phosphate in adequate phosphate diet (main effect of anti‐FGF23 antibodies, p<0.01). Since FGF23 is known to regulate the type II sodium‐phosphate co‐transporters’ expression in kidney, the current data suggest that anti‐FGF23 antibody may offer a new tool to reduce excreta phosphate in chicks.