- Alternatively activated macrophages regulate extracellular levels of the hormone placental lactogen via receptor-mediated uptake and transcytosis. Kzhyshkowska, J., Gratchev, A., Schmuttermaier, C., Brundiers, H., Krusell, L., Mamidi, S., Zhang, J., Workman, G., Sage, E.H., Anderle, C., Sedlmayr, P., Goerdt, S. J. Immunol. (2008)