Table 1.

Effect of cysteamine on atherosclerosis in LDL receptor knockout mice.

	Control (n = 19)	Cysteamine (2.2 mM in drinking water) (n = 21)	Cysteamine (8.8 mM in drinking water) (n = 22)
Weight (g)	22.4 ± 0.6	22.3 ± 0.4	22.8 ± 0.7
Cholesterol (mM)	39.9 ± 2.5	40.3 ± 1.5	38.8 ± 1.9
Triacylglycerol (mM)	4.64 ± 0.31	4.67 ± 0.29	4.99 ± 0.29
HDL-cholesterol (mM)	3.30 ± 0.24	3.34 ± 0.12	3.23 ± 0.16
LDL-cholesterol (mM)	29.6 ± 1.7	29.4 ± 0.9	26.8 ± 1.1
Cysteamine (μM)	0.0933 ± 0.034	0.251 ± 0.019	0.764 ± 0.071*
Aortic root (mm2)$	0.487 ± 0.025	0.397 ± 0.029	0.397 ± 0.026
Aortic arch (%)#	35.0 ± 1.8	26.0 ± 1.2	27.0 ± 1.1
Thoracic + Abdominal (%)	2.29 ± 0.64	1.53 ± 0.32	1.36 ± 0.27

Body weight, plasma lipids, plasma cysteamine concentrations and atherosclerotic lesions in three aortic regions (mean ± SEM) were measured in mice fed a Western diet with or without cysteamine for 12 weeks. ANOVA showed no significant difference in body weight and lipids between groups. Cysteamine concentrations in plasma were significantly higher in mice receiving the drug compared to the control group (p < 0.001, ANOVA), with the higher dose group having higher plasma concentrations than the control or lower dose groups (*p < 0.0001, Tukey's post hoc test). The inhibition of the disease was not significantly affected by dose at any of the three aortic locations examined, as assessed by either 2-way ANOVA (p = 0.65) or t-test (p = 0.93 for aortic root, p = 0.57 for aortic arch and p = 0.69 for remaining thoracic plus abdominal aorta) and data for the two doses were therefore combined. The effect of cysteamine was significant in the aortic root (^$p = 0.010; t-test) and arch (^#p = 0.00001; t-test). It appeared to cause an even greater reduction in the descending aorta but the effect only approached statistical significance (p = 0.11), probably because the level of disease was low in these regions and the measurements were consequently highly variable.