Protein and plasminogen activator (PA) production by bovine mammary epithel
ial cells cultured on inserts and the effect of calcium were studied. The c
ells cultured on inserts coated with a bovine extracellular matrix establis
hed a stable trans-epithelial resistance, and secreted apically alpha (s1)-
casein and PA. Extracellular calcium increased (P < 0.01) alpha (s1)-casein
and total proteins, but not PA activity.