Full expression of @entity5483 protein gene requires the concurrence of XXXX and triiodothyronine.

@entity1375 @entity3044 @entity5483 @entity35 @entity1063
We have examined the @entity5483 ( @entity5483 ) protein gene expression in euthyroid and @entity1375 @entity35 . @entity5483 mRNA levels were estimated by northern blot analysis of total RNA from brown adipose tissue (BAT). Stimuli were endogenous (cold) and exogenous @entity1063 (NE), @entity3044 , T3, and T4. While the euthyroid @entity35 @entity5483 mRNA levels increase 2- to 3-fold by 2 h after NE or overnight cold exposure, these stimuli and @entity3044 are ineffective in @entity1375 @entity35 . One single dose of T4, equal to the daily production rate, brings about a normal response in @entity1375 @entity35 exposed to cold overnight. @entity1375 @entity35 recover their responsiveness to NE approximately 4 h after a receptor saturating dose of T3. On the other hand, such a dose of T3 induces a 3- to 4-fold increase in @entity5483 mRNA levels in @entity1375 @entity35 without the need of exogenous NE, and this response is not reduced by raising ambient temperature to thermoneutrality (28 C). However, the following evidence indicates that T3 requires adrenergic input to stimulate the accumulation of @entity5483 mRNA: first, euthyroid animals maintained at 28 C do not respond to such a treatment. Second, when T3 was injected to @entity1375 @entity35 with unilaterally denervated BAT, only the intact side responded to T3 with an elevation of the @entity5483 mRNA levels, but both sides remained responsive to T3 + NE.(ABSTRACT TRUNCATED AT 250 WORDS)
