In vitro regulation of rat prolactin messenger ribonucleic acid poly(A) tail length: modulation by bromocriptine.

Recent analysis of endocrine gene transcripts has revealed that several hormone mRNAs exhibit regulated size changes (due to alterations in length of the 3' poly(A) tail) which may function as an additional level of control in the determination of gene expression. We have now shown, through the novel application of an organ culture technique, that prolactin mRNA exhibits a similar regulated change in poly(A) tail length when rat anterior pituitary glands are explanted. The effect is observed in glands of either male or female rats and is specific with respect to growth hormone and alpha-tubulin mRNAs. Furthermore, we have also found that the size change in prolactin mRNA is attenuated in the presence of bromocriptine, indicating regulation through a dopaminergic pathway.