The fine structural localization of acid phosphatase in the prolactin cell of the teleost pituitary following the stimulation and inhibition of secretory activity.

Fine structural studies have been made upon the prolactin cells of Poecilia latipinna when the fish is subjected to a series of changes in its environmental salinity. Under the regimen employed it is shown that the secretory mechanism of the cell is initially stimulated in fresh water and then inhibited in salt water. The latter event is accompanied by the appearance of demonstrable acid phosphatase activity within the Golgi complex and by the formation of a variety of acid phosphatase-positive bodies. The way in which this acid hydrolase activity is concerned with the removal of surplus secretory granules is described and discussed.