Table 3.

Steady-state isotopic enrichment in plasma and tissue

	Con	Def	Con +3%	Def +3%	P < 0.05
	Plasma
[1-13C;methyl-2H3]methionine (M +4 Met)	19.3 ± 1.2	21.0 ± 0.6	19.3 ± 0.4	19.8 ± 0.7
[1-13C]methionine (M +1 Met)	2.9 ± 0.3	3.6 ± 0.2	2.4 ± 0.4	3.4 ± 0.1	*
[1-13C]homocysteine (M +1 Hcys)	21.5 ± 1.1	22.1 ± 0.9	22.7 ± 0.6	22.5 ± 0.7
	Colon
[1-13C;methyl-2H3]methionine (M +4 Met)	7.4 ± 0.4	8.2 ± 0.6	5.8 ± 0.7	5.8 ± 0.5	†
[1-13C]methionine (M +1 Met)	1.2 ± 0.02	1.7 ± 0.1	1.1 ± 0.1	1.4 ± 0.1	*†
[1-13C]homocysteine (M +1 Hcys)	10.2 ± 0.4	10.3 ± 0.5	9.4 ± 0.5	9.5 ± 0.4
[1-13C]Met/[1-13C]Hcys	0.1 ± 0.01	0.2 ± 0.01	0.1 ± 0.01	0.3 ± 0.01	*
	Liver
[1-13C;methyl-2H3]methionine (M +4 Met)	5.2 ± 0.2	7.8 ± 0.7	4.4 ± 0.2	5.9 ± 0.5	*†
[1-13C]methionine (M +1 Met)	2.2 ± 0.2	3.0 ± 0.1	2.3 ± 0.1	3.2 ± 0.3	*
[1-13C]homocysteine (M +1 Hcys)	8.1 ± 0.5	8.5 ± 0.7	7.8 ± 0.6	8.8 ± 0.6
[1-13C]Met/[1-13C]Hcys	0.3 ± 0.04	0.4 ± 0.04	0.3 ± 0.1	0.4 ± 0.03	†
	Small Intestine
[1-13C;methyl-2H3]methionine (M +4 Met)	2.6 ± 0.2	4.6 ± 1.1	2.9 ± 0.6	3.2 ± 1.3
[1-13C]methionine (M +1 Met)	0.5 ± 0.2	0.9 ± 0.3	0.4 ± 0.03	0.7 ± 0.2
[1-13C]homocysteine (M +1 Hcys)	9.2 ± 0.7	6.8 ± 0.8	8.4 ± 0.7	7.7 ± 0.7	*
[1-13C]Met / [1-13C]Hcys	0.06 ± 0.02	0.1 ± 0.03	0.1 ± 0.01	0.1 ± 0.03	*

Data are means ± SE (n = 3–4/group). Met, methionine; Hcys, homocysteine. P < 0.05.

^*Diet,

^†DSS.