Storage and release of secretory granules in human prolactinomas: modification by bromocriptine.
Electron microscopic morphometric evaluation of the effects of bromocriptine on human prolactinomas during and after short-term parenteral (7 days) and long-term peroral (4-6 weeks) treatment showed that a reduction in size of prolactinoma cells occurs within a few days (half-time to maximum shrinkage, 2.2 days). The number of secretory granules discharged into the intercellular space increased after short-term treatment by a factor of three but the total volume of stored secretory granules did not change significantly. The total volume of cellular lysosomes, both primary and secondary, decreased significantly to about one-half of the pretreatment value. The amount of stored lipoids, end-products of lysosomal activity, decreased in specimens treated for 7 days, but returned to pretreatment levels in specimens treated for 4-6 weeks, suggesting that lysosomal material is discharged from the cells together with the secretory material.
D000328:Adult; D001971:Bromocriptine / Q000627:therapeutic use*; D003594:Cytoplasmic Granules / Q000648:ultrastructure*; D005260:Female; D006801:Humans; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D010911:Pituitary Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000648:ultrastructure*; D011388:Prolactin / Q000378:metabolism*; D013997:Time Factors
D001971:Bromocriptine; D011388:Prolactin