TY  - JOUR
A1  - ,  
T1  - Hyperactivity and proliferation of prolactin cells induced in vitro by met-enkephalin
JO  - Eur. J. Anat.
SN  - 1136-4890
Y1  - 1997
VL  - 1
SP  - 89
EP  - 95
UR  - http://www.eurjanat.com/web/paper.php?id=97020038
KW  - Rat pituitary
KW  - prolactin
KW  - met­enkephalin
KW  - cellular proliferation.
N2  - In order to determine  whether or not met­ enkephalin is able to modulate the in vitro activity and  proliferation rate of rat prolactin cells, pituitary monolayer cultures from male rats were treated    with 1O-6M met -enkephalin and an immunocytochemical and morphometric study was carried out. The opio id induced significant increases in cellular and nuclear areas (p<0.05) with respect to control   dishes. The proliferation rate was determined as the labelling index for peNA by double immunocytochemistry for peNA and prolactin; met-enkephalin induced a significant increase in total PCNA-expressing cells (p<0.05), the numerical density of prolactin immunoreactive cells (p<0.05)and the prolifera­tion rate of prolactin cells (p<O.Ol). Moreover, significant differences were observed between peNA and non-PCNA prolactin immunoreactive cells, the former showing a significantly higher nuclear area (p<0.05) with no significant differ­ ences in the cellular or cytoplasmic areas. These results suggest a direct action of the opioid on pituitary cells and point to the possible existence of a physiological role of the opio id in modulating the proliferation of these cells.
ER  -