Horm Metab Res 1993; 25(11): 564-568
DOI: 10.1055/s-2007-1002178
Originals Basic

© Georg Thieme Verlag, Stuttgart · New York

Prolactin Stimulation of Protein Kinase C in Isolated Mouse Mammary Gland Nuclei

G. Fan, J. A. Rillema
  • Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan, U.S.A.
Further Information

Publication History

1992

1993

Publication Date:
14 March 2008 (online)

Summary

Prolactin (PRL) was found to stimulate protein kinase C (PKC) activity in a transient fashion in isolated nuclei derived from the mammary glands of 12-14 day pregnant mice. PKC activation was time and dose dependent and was blocked by staurosporine. With l0 ng/ml PRL a maximum stimulation of PKC occurred at 3 min, whereas with 50 ng/ml the effect was maximal at 2 min. After 5 min, the effect of PRL on PKC activity was no longer detected. Specificity of the PRL effect on PKC was established by snowing that bovine growth hormone and insulin at 10 ng/ml had no effect on PKC activity. Multiple proteins in the nuclear preparations were shown to be phosphorylated by the addition of PKC derived from rat brain tissue. These studies have important implications regarding the possible direct effects of prolactin in the nucleus of mammary cells.