Regulation of Protein Synthesis in Hen's Oviducts

I. Removal of Extracellular and Intracellular Proteins and Their Effects on Protein Synthesis

抄録

The minced oviducts prepared from laying hens contained considerable amounts of extracel-lular proteins (about 60mg per g of the wet oviducts), which could largely be removed (about 80%) by washing four times with chilled Krebs-Ringer-Tris buffer, pH 7.6.
When the washed, minced oviducts were incubated at 37° with the buffer, intracellular proteins were increasingly secreted to the extracellular fluids as the incubation time was in-creased and the amounts of intracellular proteins decreased concomitatnly, suggesting that the rate of secretion of intracellular proteins was faster than that of protein synthesis under the conditions used (without addition of amino acids to the medium). Repeated 5-min incuba-tions (five to seven times) resulted in the secretion of intracellular proteins in amounts of 100mg or more per g of the wet oviducts.
The secretion rate of intracellular proteins was almost constant at 37° regardless of the volume of buffer used for the incubation, and no secretion occurred at 4° even after 5 h. It ap-peared that a 30 min period was required for the secretion of intracellular proteins from the oviducts at. 37° and that the rate of secretion was not affected appreciably by the amount of secreted proteins present in the extracellular fluids.
The protein synthesis activity in the washed, preincubated minced oviducts was independ-ent of the amount of intracellular proteins involved but was dependent upon that of secreted proteins present in the extracellular fluids.