Angiotensin II mediates beta endorphin like immunoactivity release in rat pituitary cell culture

The effect of angiotensin II (Ang II) on pituitary beta endorphin like immunoactivity (beta END-LI) release was studied in monolayer culture of normal rat pituicites. Ang II stimulated beta END-LI release into the culture media. This release of beta END-LI increased with longer incubation time and with higher doses of Ang II. The beta END-LI response was similar to the pattern of Ang II mediated ACTH release. Ang II stimulated beta END-LI release was blocked by cycloheximide and decreased by corticosterone (5 nmol/l). Successively higher concentrations of [SAR GLY]Ang II, a known Ang II antagonist, induced greater inhibition of Ang II stimulated beta END-LI release. Gel chromatography of pooled media from control and Ang II stimulated cells revealed three peaks of beta END-LI which migrated with the void volume, beta lipotropin (beta LPH) and beta endorphin. The relative amount of beta END-LI in these peaks [(BEND-LI peak + total beta END-LI in column) x 100%] from media of control and stimulated cells were as follows: (1) Void 7% and 19% (2) beta LPH 50% and 52% (3) beta endorphin 43% and 29%.