Table 1.

Effects of short-term T3 treatment on BW, HW, and plasma T3 levels.

	HO	HOT3
Anatomic data
Body weight day 0 (g)	22.1 ± 0.5	22.1 ± 0.6
Body weight day 44 (g)	22.7 ± 0.4	22.6 ± 0.5
Total heart weight/TL (mg/cm)	41.3 ± 1.1	58.1 ± 0.6*
LV weight/TL (mg/cm)	24.0 ± 1.4	33.1 ± 1.2*
Thyroid hormone status
T3 levels (nM)	0.1 ± 0.1	47.5 ± 4.2*

Twelve mice were allowed ad libitum access to food containing PTU for 44 days. Six randomly chosen mice were injected with T3 at day 42, 43, and 44. Controls received vehicle. Mice were sacrificed at day 45. Body weight remained unchanged during the experiment. Total heart weight increased by 41%, and LV weight increased by 38%. T3 treatment resulted in 475 times higher T3 levels in the hyperthyroid mice. Heart weight was corrected for TL, tibia length; HO, hypothyroid; HOT3, hyperthyroid. Values are means ± SEM; *p < 0.05.