Figure 5. Maxi-K_Ca channel is required for EGFR-mediated up-regulation of proliferating cell nuclear antigen (PCNA).

A and B, Western blots of basilar arteries exposed to aCSF without (CTR) or with EGF in vivo, blotted for phospho-EGFR (A) and reblotted for EGFR (B); aCSF without or with EGF (10 μg ml⁻¹) was infused into cisterna magna at 1 μl h⁻¹ for 24 h via mini-osmotic pump. C, E, G, I, fluorescence images of rat basilar artery sections immunolabelled for PCNA for a control rat (C), for a rat with cisterna magna infusion of EGF (E), for a rat with cisterna magna infusion of EGF plus iberiotoxin (IBTX) (G), for a rat with cisterna magna infusion of EGF plus AG-1478 (I); all infusions were for 3 days. D, F, H, J, fluorescence images of rat basilar artery corresponding to sections shown above, labelled with diamidino-2-phenylindole (DAPI) to show nuclei. K, bar graph of the PCNA index (number of nuclei with PCNA labelling divided by number of nuclei in the tissue section) for the four conditions, control, cisterna magna infusion of EGF, cisterna magna infusion of EGF plus iberiotoxin, cisterna magna infusion of EGF plus AG-1478; **P < 0.01; 3–4 arteries for each condition.