thyrotropin-releasing hormone ( trh ) stimulation of prolactin secretion from gh3 cells , cloned rat pituitary tumor cells , is associated with 1 ) hydrolysis of phosphatidylinositol 4,5-bisphosphate to yield inositol trisphosphate ( insp3 ) and 2 ) elevation of cytoplasmic free ca2+ concentration [ ( ca2+ ] i ) , caused in part by mobilization of cellular calcium .
C0010834
cytoplasmic
C0007634
cellular