Fig. 7. SU5402 treatment decreases epithelial cell proliferation but does not cause apoptosis of the epithelial buds. (A-D) BrdU incorporation at 44 hours was detected with fluorescently labeled BrdU. The proliferating cell nuclei appear as green punctate spots. Peanut lectin-rhodamine stains the epithelium red and anti-perlecan stains mesenchyme and the basement membrane blue. The images in B, D, E and G are compressed stacks of optical sections through the entire gland. (A) Light micrographs of control gland. (B) Control gland shows BrdU labeling concentrated on the epithelial buds and at the periphery of the mesenchyme. (C) Light micrographs of SU5402-treated gland. (D) SU5402 treatment results in less BrdU labeling on the epithelial buds. Proliferating cells are still apparent in the mesenchyme. (E-I) SU5402 treatment does not cause increased apoptosis at 20 or 44 hours. Apoptosis of mesenchyme cells at the edges and on the surface of the glands in culture was detected with TUNEL staining in red. FITC-peanut lectin stains the epithelium green and anti-perlecan stains mesenchyme and the basement membrane blue. (E) Low power whole-mount view of control gland cultured for 20 hours shows red apoptotic nuclei in the mesenchyme. (F) Higher power section showing apoptotic nuclei in the mesenchyme, but none are detected in the epithelium. (G) Low power whole-mount view of gland treated for 20 hours with SU5402. (H) Higher power section showing apoptotic nuclei in the mesenchyme. (I) The fluorescent BrdU and apoptosis staining were quantitated using the MetaMorph image analysis program. The total fluorescent pixels were expressed as a ratio of the area of the gland. At least 5 glands/condition were used for quantitation and the experiments were repeated three times. ^*P<0.05, ^**P<0.01, ns, not significant.