Fig. 5. Selective knockdown of the Ins(1,4,5)P₃-R1 isoform from the ECs by using the cremasteric VCCC. (A) Immunoblots of ECs or VSMCs from the VCCC that were stained for Ins(1,4,5)P₃-R1, Ins(1,4,5)P₃-R2 or Ins(1,4,5)P₃-R3. Representative β-actin staining from stripped immunoblots is also shown. Experiments included lanes loaded with samples from control conditions, the addition of Ins(1,4,5)P₃-R1 siRNA to ECs only, or the addition of control siRNA (c-siRNA) to ECs only. (B) Quantification of ratioed immunoblots. ^*P<0.05. (C,D) Immunostain for Ins(1,4,5)P₃-R1 on transverse sections of cremasteric VCCC before (C) and after (D) application of Ins(1,4,5)P₃-R1 siRNA to the ECs; note the sparse staining for Ins(1,4,5)P₃-R1 in the ECs, but the isoform is still observed in the VSMCs. Arrows demonstrate Ins(1,4,5)P₃-R1 expression within the pores of the Transwell. (E,F) On the cremasteric VCCC, Ins(1,4,5)P₃-R2 and Ins(1,4,5)P₃-R3 show expression within the monolayers of the cells only. Scale bar: 10 µm.