My first though is to use iTunes sharing.
Add the media to iTunes on the MP, then enable sharing in iTunes (iTunes Preferences > Sharing "Share my library on my local network". On the MBP, the shared library from the MP should show up in the media list (left side) under "Shared" (if not, check iTunes preferences Sharing "Look for shared libraries" is enable).
You should [on the MBP] find your video/audio under the MP's shared library - it will play (stream) from the MP.