Figure 4.

h-RA-IMCA MT and EC-dependent vasodilation linked to high resolution structure. (A) TEM from cannulated and pressurized h-RA-IMCAs. Images show multiple sites of contact between ECs and SMCs (r-SMC and l-SMC). Severely damaged ECs (ghost cells) remained in close contact with adjacent ECs. Inflammatory cell; bar =1 µm. l-SMCs, when present, are always found between the r-SMC and EC layers. SEM 1–3, indicates h-RA-IMCAs processed for SBF-SEM (Supplementary material online, Figure S3A). The level of MT (B) and vasodilation to 10 nM BK (C) in each h-RA-IMCA subsequently processed for EM (Patients 1–8) reveals arterial ultrastructure is markedly altered in arteries without MT, with extensive thickening of the elastin layer separating the ECs and SMCs (IEL).