Table 1.

Characteristics of deiodinase-deficient adult mice compared with wild-type

Knockout models	D1−/−	D2−/−	D3−/−	D1/D2−/−
Serum T4	↑	↑	↓	↑
Serum T3	Normal	Normal	↓	↓
Serum rT3	↑	NR	NR	↑
TSH	Normal	↑	Normal or modest ↑	↑
Systemic phenotype	Euthyroid	Euthyroid	Hypothyroid	NR
Specific features	Increased fecal excretion of iodothyronines	Mild cold intolerance, hearing impairment	Central hypothyroidism, growth retardation, neonatal brain thyrotoxicosis	NR
Reproduction	Normal	Normal	Impaired	NR

NR, Not reported. The table contains data from NR (149,195,242,293,307). Partial data available on the D1/D2 combined knockout mice are available as unpublished observation cited in Ref. 35 and personal communication of Galton et al. cited in Ref. 80.