Morphometric effect of prostaglandin E1 and F2 alpha on lactating bovine mammary tissue in vitro.

Mammary explants from six lactating cows were incubated for .17, 4, 8, and 12 h in medium containing prostaglandin E1 or prostaglandin F2 alpha tromethamine salt at 0, 1, 10, or 50 micrograms/ml to determine if prostaglandins alter tissue structure. Explants were fixed, dehydrated, embedded in plastic resins, and sectioned at .5 to 1.0 mu. Tissue area was partitioned by light microscopy into normal, damaged, or debris epithelial; normal or debris lumenal; or stromal areas. All tissue samples exhibited signs of deterioration as incubation progressed. Prostaglandin E1 treatment maintained more secretory epithelium and resulted in less epithelial debris and lumenal debris than controls. Prostaglandin F2 alpha-treated tissue had less epithelial debris and normal lumenal area than tissue receiving no prostaglandin during the limited incubation. The three concentrations of prostaglandins studied did not identify optimal prostaglandins for mammary tissue incubated but indicated concentrations below 1 microgram prostaglandin E1 or F2 alpha/ml should be studied. The response of mammary tissue to prostaglandin was affected by donor milk production. Increases of normal epithelial area were correlated with decreases of damaged and debris areas. Prostaglandins E1 and F2 alpha appeared to be beneficial to healthy mammary tissue incubated under limited conditions.