L-3,4-Dihydroxyphenylalanine (L-DOPA) Modulates Corticotrophs Turnover.

SANTIAGO JORDI ORRILLO; DE DIOS NATALY; MORENO AYALA M A; ZARATE S; GOTTARDO MF; FERRARIS J; PISERA D

Orlando

Congreso; ENDO annual meeting; 2017

L-Dopa plus peripheral aromatic L-amino acid decarboxylase (AADC) inhibitors is the goldstandard treatment for Parkinson?s disease. L-Dopa crosses the blood brain barrier and isconverted to DA by AADC. Since DA induces apoptosis in anterior pituitary, our hypothesisis that L-Dopa modulates the pituitary cell turnover by its conversion to DA. First, theexpression of AADC was studied by immunofluorescence. We observed in pituitarysections that the enzyme is expressed in the anterior lobe. Likewise, GH3 and AtT20pituitary cell lines were immunoreactive for AADC. These results were confirmed bywestern blot. To study the effects of L-Dopa on cell renewal, GH3 cells were incubated withL-Dopa (1uM, 8 h) in the presence of an AADC inhibitor (NSD 1015, 1uM). Apoptosis andproliferation were determined by TUNEL and BrdU incorporation, respectively. L-Dopaincreased the percentage of TUNEL-positive cells, but the concomitant inhibition of AADCrevealed an antiapoptotic effect of L-Dopa (C: 13.65; L-Dopa: 22.73; NSD: 14.50; L-Dopa+NSD: 7.57, p