Influence of prolactin on ultrastructure of pinealocyte in sexually immature female pigs: a quantitative study.

The effects of long-term prolactin administration on the ultrastructure of pinealocytes in young female pigs were studied by means of morphometric analysis. Prolactin administration for 26 consecutive days resulted in an increase in the cytoplasmic dense bodies type MBB-1 and some differences in their structure. There were no significant changes in the other cytoplasmic structures. Prolactin appeared to stimulate the process of formation of dense bodies.