Rat liver activity

STATSb is repeatedly activated by GHR/ JAK2-catalyzed tyrosine phosphorylation in concert with the onset of each male plasma GH pulse. STATSb thus imdergoes repeated cycles of translocation from the cytoplasm into the nu-clens, and then back out to the cytoplasm [155, 158]. For example, if the liver is excised from a rat killed at the time of a plasma GH pulse, then STATSb is found to be tyrosine-phosphorylated and localized to the nuclens, whereas if the liver is excised from a rat killed at a time point between snccessive plasma GH pulses, STATSb is inactive and cytoplasmic. This close temporal linkage between plasma GH pattern and the activation state of liver STATSb has been confirmed in intact male rats killed at times shown to be specifically associated with spontaneous peaks or troughs of the plasma GH rhythm [159]. In contrast, in female rat liver, active, nuclear STATSb... 

Fig. 3. Palmityl-CoA synthetase activity of developing rat liver. Activity is expressed as nanomloes of palmityl-CoA produced per min per mg protein (Warshaw, 1972).

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