The Effects of Liver Preparation on Prolactin Release from Pituitary Tissue in vitro

Abstract

<p>The effects of liver on pituitary prolactin (PRL) secretion were investigated using an in vitro organ culture system. It was determined that various preparations of liver when coincubated with pituitary tissue resulted in a diminished PRL content in the bathing culture medium. Female Wistar rats (>200gm) provided the source for liver chunks (~150mg) that were coincubated with pituitary tissue obtained from female Wistar rats (>200gm) primed with estradiol-17-β and progesterone. The PRL content of the culture medium obtained from the liver - pituitary coincubate was reduced significantly (p<.001) compared to control. This effect could not be attributed to PRL degradation and/or binding to liver and was therefore interpreted as inhibition of secretion. The effect was partly but not completely antagonized by the addition of Haldol at concentrations ranging up to 1000nM.</p> <p>It was also noted that the diminished PRL content was observed when methanol extracts of male and female livers were coincubated with male and female (primed and unprimed) pituitary tissue. It is concluded that factors associated with liver and extracts of liver inhibit the secretion of prolactin. These factors are thought not to mediate all of their actions through the dopamine receptor as maximally effective concentrations of Haldol only partially eliminate this inhibition.</p>