Zone Electrophoresis and Prolactin Activity of Rat Adenohypophysis Cultivatedin Vitro

Abstract

Homogenates of the adenohypophysis from the intact rat and of adenohypophysial explants cultivated in vitro for 3 days, and the culture media in which these explants had been maintained, were assayed for protein content and for prolactin activity. In the 3 groups, the mean concentrations of protein per single whole pars distalis (AP)were, respectively, 0.46, 0.47 and 0.20 mg/AP; the mean activities of prolactin were, respectively, 0.26, 0.34 and 0.80 IU/AP. These synthesizing both protein and prolactin during the culture period. Samples of the 3 groups were subjected to zone electrophoresis in polyacrylamide gel. After electrophoresis, each gel was sliced into 4 segments and assayed for prolactin activity. Prolactin, demonstrable in the segment adajcent to the anode, markedly increased in the cultivated explants and in the culture medium. The increase in prolactin activity was correlated with a shift in the number of bands and their intensity of staining.