Table 2.

Serum amino acid levels in Fah-deficient mice repeatedly injected i.v. or i.m. with FAH mRNA-LNPs

Amino acid levels in serum (μM)	Fah-deficient mice NTBC−RNA+ i.m.	Fah-deficient mice NTBC−RNA+ i.v.	WT mice NTBC−PBS+
Gly	154.7 ± 58.1	96.9 ± 18.8 ns	144.9 ± 8.3
Ala	331.1 ± 103.7	372.6 ± 77.9 ns	305.1 ± 35.1
Pro	119.1 ± 34.0	86.9 ± 14.2 ns	102.5 ± 14.2
Val	174.8 ± 22.0	129.4 ± 8.5 ns	126.1 ± 7.5
Thr	19.8 ± 9.5	13.7 ± 1.8 ns	13.1 ± 0.7
Leu/Ile	203.0 ± 19.9	164.7 ± 16.2 ns	147.5 ± 11.3
Orn	193.4 ± 48.8	130.2 ± 20.5 ns	110.4 ± 17.3
Asp	35.1 ± 11.1	21.9 ± 3.3 ns	15.2 ± 2.4
Gln	4,624.6 ±1,934.1	3,745.3 ± 535.5 ns	3,462.4 ± 274.0
Glu	89.6 ± 23.2	50.1 ± 7.1 ns	51.5 ± 6.6
His	2,065.8 ± 925.3	1,207.0 ± 59.3 ns	715.4 ± 125.9
Phe	56.8 ± 15.0	57.0 ± 9.2 ns	69.1 ± 7.5
Cit	48.0 ± 8.4	48.5 ± 7.0 ns	50.6 ± 2.1
Hci	1.3 ± 0.7	0.8 ± 0.3 ns	3.7 ± 0.5
Trp	495.3 ± 55.6	443.1 ± 46.4 ns	415.7 ± 28.6
Arg	112.1 ± 10.5	87.6 ± 26.9 ns	72.8 ± 18.7
Asa	0.4 ± 0.3	0.8 ± 0.6 ns	0.5 ± 0.2
Met	55.0 ± 19.1	39.3 ± 5.2 ns	41.2 ± 3.5

NTBC was withheld from Fah-deficient mice on day 5 prior to repeated injection i.m. or i.v. with FAH mRNA-LNPs. Number of mice analyzed: Fah-deficient mice NTBC⁻RNA⁺ i.m. n = 5; Fah-deficient mice NTBC⁻RNA⁺ i.v. n = 4; WT mice NTBC⁻PBS⁺ n = 5. Analyses were performed on serum collected from Fah-deficient mice on day 21 according to the schedule depicted in Figure 3A. WT, shown for comparison purposes, were injected once i.v. with PBS and euthanized 24 h later. Gly, glycine; Ala, alanine; Pro, proline; Val, valine; Thr, threonine; Leu/Ile, leucine/isoleucine; Orn, ornithine; Asa, argininosuccinate; Gln, glutamine; Glu, glutamic acid; Phe, phenylalanine; Cit, citrulline; Hci, homocitrulline; Trp, tryptophan; Arg, arginine; Asn, asparagine; Met, methionine. Serum amino acid levels in mice injected repeatedly i.m. versus i.v. were not significantly different: p > 0.05 (Student’s t test).