Figure 4From: Tumour-stromal interactions Reciprocal regulation of extracellular matrix proteins and ovarian steroid activity in the mammary glandCellular localization and ovarian steroid regulation of α5β1 integrin in mouse mammary glands during development. (a) Frozen sections of mammary glands from immature, pubertal, sexually mature (3-, 5-, 10-week-old, respectively), early pregnant (9–12 days), late pregnant (19–21 days) and lactating (7–10 days) mice were immunostained with antibody to the α5β1 integrin. Note that staining is seen around ducts at 5 and 10 weeks of age and around alveoli in early pregnant mice. No staining was seen at 3 weeks of age or at late pregnancy and lactation. Mag. 100X. (b) Mammary glands were removed from 10-week-old mice that were ovary intact (intact), ovariectomized for 1 week (OVX), or OVX given a single i.p. injection containing 17β-estradiol (1 μg) + progesterone (1 mg) (E + P) and sacrificed 24, 48 or 72 hour later. Frozen sections were stained with antibody to α5β1 integrin and fluorescence staining intensity (measured as average pixel brightness) was quantitated [20]. * P < 0.05 that OVX α5β1 integrin staining intensity is lower than intact. ** P < 0.05 that at 24, 48, and 72 hr post E + P injection, α5β1 integrin staining intensity is greater than OVX.Back to article page