Table 2.

Effect of pyridoxine on oxalate and glyoxylate production in stably transfected CHO cells incubated with glycolate.

Cell line	Oxalate (μM)		Glyoxylate (μM)
	Standard B6	Low B6	Standard B6	Low B6
100 μM glycolate
CHO GO AGT-MA	2.2 ± 1.7	4.9 ± 0.8a,*	0.6 ± 0.2	1.1 ± 0.3
CHO GO AGT-mi	5.8 ± 0.8b,*	7.2 ± 1.0b,**	0.7 ± 0.2	1.1 ± 0.3
CHO GO AGT-170	16.2 ± 2.8b,**	30.2 ± 2.2a,b,***	2.1 ± 0.7b	4.7 ± 0.4a,b,***
CHO GO	69.7 ± 7.0	61.1 ± 8.9	6.3 ± 0.2	9.6 ± 0.2
250 μM glycolate
CHO GO AGT-MA	11.9 ± 4.3	11.1 ± 1.9	1.2 ± 0.3	2.0 ± 0.4a,*
CHO GO AGT-mi	17.2 ± 3.3	20.6 ± 1.6b,***	1.7 ± 0.9	3.2 ± 0.1b,***
CHO GO AGT-170	51.9 ± 6.7b,***	86.7 ± 4.3a,b,***	8.1 ± 2.5b,**	18.4 ± 2.4a,b,***
CHO GO	139.9 ± 17.8	128.2 ± 5.2	24.8 ± 0.1	31.7 ± 1.7

Cells were grown at least 4 weeks in either standard pyridoxine concentration (0.3 μM) or with low pyridoxine concentration (< 0.3 μM) (see Experimental procedures). Adapted cells were incubated with 100 or 250 μM glycolate for 24 h. The concentrations of oxalate and glyoxylate released in the media were measured by IC and reverse phase HPLC, respectively. Results (n = 3–4, except CHO GO, n = 2) are expressed as means ± SD. The background oxalate (1.7 μM) and glyoxylate (2.3 μM) measured in CHO wt incubated with 250 μM glycolate was subtracted from the data. A significant difference in oxalate and glyoxylate production between standard and low concentrations of pyridoxine is indicated by (a) between cells expressing AGT variants by (b). Statistical analysis was done by Student’s t-test (raw p values: *p < 0.05; **p < 0.01; ***p < 0.001). Bold values indicate p < 0.05 after Bonferroni correction.