Bromocriptine suppression of dispersed pituitary lactotrophs from estrogen-pretreated rats: a quantitative electron microscopic study

Dispersed rat lactotrophs were treated with bromocriptine (10−10 M) for either 30 min or 3 h to investigate its effect on cell morphology using light and electron microscopy and ultrastructural morphometry. After 30 min, lactotrophs treated with bromocriptine exhibited an increase in storage granule size (p < 0.05). Crinophagy was also evident and a significant increase in lysosome volume density was observed (p < 0.001). However, no significant change in prolactin content in the media was detected until 3 h of incubation in bromocriptine (p < 0.05). At this time a nonsignificant decrease in Golgi region volume density was also observed.