RT Journal Article T1 Oral Acid Load Down-Regulates Fibroblast Growth Factor 23. A1 Vidal, Angela A1 Pineda, Carmen A1 Raya, Ana I A1 Rios, Rafael A1 Espartero, Azahara A1 Muñoz-Castañeda, Juan R A1 Rodriguez, Mariano A1 Aguilera-Tejero, Escolastico A1 Lopez, Ignacio K1 FGF23 K1 PTH K1 Acid intake K1 Kidney AB Increased dietary acid load has a negative impact on health, particularly when renal function is compromised. Fibroblast growth factor 23 (FGF23) is a bone-derived hormone that is elevated during renal failure. The relationship between metabolic acidosis and FGF23 remains unclear. To investigate the effect of dietary acid load on circulating levels of FGF23, rats with normal renal function and with a graded reduction in renal mass (1/2 Nx and 5/6 Nx) received oral NH4Cl for 1 month. Acid intake resulted in a consistent decrease of plasma FGF23 concentrations in all study groups when compared with their non-acidotic control: 239.3 ± 13.5 vs. 295.0 ± 15.8 pg/mL (intact), 346.4 ± 19.7 vs. 522.6 ± 29.3 pg/mL (1/2 Nx) and 988.0 ± 125.5 vs. 2549.4 ± 469.7 pg/mL (5/6 Nx). Acidosis also decreased plasma PTH in all groups, 96.5 ± 22.3 vs. 107.3 ± 19.1 pg/mL, 113.1 ± 17.3 vs. 185.8 ± 22.2 pg/mL and 504.9 ± 75.7 vs. 1255.4 ± 181.1 pg/mL. FGF23 showed a strong positive correlation with PTH (r = 0.877, p< 0.0001) and further studies demonstrated thatacidosis did not influence plasma FGF23 concentrations in parathyroidectomized rats, 190.0 ± 31.6 vs.215 ± 25.6 pg/mL. In conclusion, plasma concentrations of FGF23 are consistently decreased in rats with metabolic acidosis secondary to increased acid intake, both in animals with intact renal function and with decreased renal function. The in vivo effect of metabolic acidosis on FGF23 appears to be related to the simultaneous decrease in PTH. PB MDPI YR 2022 FD 2022-02-28 LK http://hdl.handle.net/10668/21458 UL http://hdl.handle.net/10668/21458 LA en NO Vidal A, Pineda C, Raya AI, Rios R, Espartero A, Muñoz-Castañeda JR, et al. Oral Acid Load Down-Regulates Fibroblast Growth Factor 23. Nutrients. 2022 Feb 28;14(5):1041 DS RISalud RD Apr 10, 2025