title: [Comparison of free and membrane-bound polyribosomes of human placenta in different periods of pregnancy].
abstract: The amount and sedimentation properties of free and membrane-bound polyribosomes of human placenta were studied at different stages of normal pregnancy. The amount of total ribosomes decreases considerably with an increase in the time of pregnancy, while a portion of membrane-bound polyribosomes tends to increase. It is shown that sedimentation patterns of polyribosomes of the both types change during development of pregnancy. These alterations may be associated with changes in a set of proteins which are produced by the placenta during its ripening.
mesh_terms: D002462:Cell Membrane / Q000648:ultrastructure; D005260:Female; D006801:Humans; D010920:Placenta / Q000502:physiology / Q000648:ultrastructure*; D011132:Polyribosomes / Q000378:metabolism / Q000648:ultrastructure*; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D014176:Protein Biosynthesis
vernacular_title: Cravnitel'noe izuchenie svobodnykh i membranosviazannykh poliribosom platsenty cheloveka v razlichnye sroki beremonnosti.