Examination of rat placental lactogen and prolactin at 6-hr intervals during midpregnancy.

@article{Tonkowicz1983ExaminationOR,
  title={Examination of rat placental lactogen and prolactin at 6-hr intervals during midpregnancy.},
  author={P A Tonkowicz and James L. Voogt},
  journal={Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine},
  year={1983},
  volume={173 4},
  pages={583-7}
}
The Nb2 node lymphoma cell bioassay was verified in our laboratory as a sensitive, reproducible, and accurate bioassay for measurement of serum rat placental lactogen (rPL). Blood samples taken every 6 hr during pregnancy showed a significant peak of rPL secretion in the late afternoon on Day 11. The inverse relationship between rPL and nocturnal prolactin (PRL) surges is shown.