Table I.

Serum T3, T4 and TSH levels in five groups.

Group	Number	T3 (nmol/l)	T4 (nmol/l)	TSH (μIU/ml)
C	12	0.83±0.03	49.81±1.08	1.02±0.14
Hypo	11	0.60±0.03*	18.19±1.72*	19.78±3.01*
DON	11	0.57±0.02*	18.58±0.91*	19.55±3.29*
T4	10	0.83±0.08	52.42±1.92	1.21±0.32
T4+DON	11	0.77±0.07	52.71±2.04	1.07±0.15

Data are expressed as the mean ± SEM. C, control group; Hypo, hypothyroid group; DON, hypothyroid rats treated with 0.005% (w/v) DON; T4, hypothyroid rats treated with 6 μg T4/100 g body weight; T4+DON, hypothyroid rats treated with 6 μg T4/100 g BW beside adding 0.005% (w/v) DON to the drinking water.

^*P<0.01, vs. C.

T3, triiodothyronine; T4, thyroxine; DON, donepezil; THS, thyroid stimulating hormone; SEM, standard error of the mean; w/v, weight/volume.