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Fig. 5.
6ß4 is expressed by endothelial cells in the adult mystacial
pad. (A) Schematic representation of the vasculature associated with a whisker
follicle (wf) in the adult mouse mystacial whisker pad. Small fur hairs (h)
and a large whisker (w) are shown in dark gray. The epidermis (e), small hair
follicles, and large whisker follicle are shown in light gray. The whisker
follicle is surrounded by a vascular sinus (pink) which is enclosed by a dense
collagen capsule (medium gray). Arteries, arterioles and capillary beds are
red; veins and venules are blue; nerves are green; and piloerector muscles are
brown (Fundin et al., 1997a;
Fundin et al., 1997b;
Rice et al., 1997). Dashed
rectangles indicate areas comparable to sites in B,C, and in higher
magnification in D-I. (B-I) Immunofluorescence staining of longitudinal
sections of an adult whisker follicle. Adjacent sections were immunostained
with anti-s100 (B,C: green) for Schwann cells on nerve axons. Double
immunostaining with MEC 13.3 (B: red) labels PECAM-1 on the endothelium of all
blood vessels. Double immunostaining with 346-11A (C: red) labels ß4 on
the perineurium of nerves and endothelium of many blood vessels. Regions of B
and C (dotted boxes) are shown at higher magnification (D,F,H) and (E,G,I)
respectively. Arrows indicate nerves. Arrowheads indicate examples of
ß4-positive vessels; dotted ovals indicate ß4-negative vessels.
ß4 labeling is also present on basal keratinocytes (E, arrows) of the
epidermis and hair follicles. Scale bars: 100 µm.