The Effects of Culture Conditions on Prolactin and Growth Hormone Production by Rat Anterior Pituitary Cells*

Publisher Website
Google Scholar
Abstract
The production of PRL and GH by rat pituitary cell cultures was evaluated over a 9-day period in 20 commercially available media supplemented with 5% horse serum (HS) or 5% calf serum. The quantity of PRL produced by cells maintained in a-modified Eagle medium (α-MEM) containing 5% HS was consistently greater than that in all other combinations of media and sera examined. PRL production in α-MEM was increased from 4.7 to 8.1 μg PRL/25,000 pituitary cells during a 9-day culture (72% ↑) as HS concentrations were increased from 1.25% to 20% however, the rate at which PRL was released into the medium during culture was unaffected by HS concentrations above 2.5%. Maximum hormone production was achieved when pituitary cells were cultured at 37 C in CO2-NaHCO3-buffered α-MEM at a pH of 7.8. Changes in medium osmolality from 250 to 350 mosm/kg H2O did not significantly affect PRL secretion. Under the conditions employed in this study, rat somatotrophs did not significantly increase their original GH content during culture. Since hormone production by rat pituitary cells can be significantly altered by a variety of nonhumoral factors, such as medium pH, buffer composition, and medium formulation, culture conditions must be adequately defined in order to interpret correctly experimental manipulations. This study represents a step in that direction.