Figure 2.

Representative images (A) and the quantitative analysis (B) acquired by transmission electronmicroscopy (TEM) in sham-operated control (SC; n = 4), ischaemic control dogs (IC; n = 6), and in dogs infused with nitrite with (NaNO₂+I/R; n = 4) and without ischaemia (NaNO₂; n = 4). For each n, 5 images were evaluated and averaged. (A) There were no significant differences between the sub-sarcolemmal (SSM), inter-myofibrillar (IMF) and the perinuclear (PN) regions, concerning the changes of mitochondrial morphology in response to I/R or nitrite treatment. The images show that compared to the SC group, in dogs subjected to a 25 min I/R, substantial swelling and disorganization of cristae of the mitochondrial matrix occurred in all the three examined regions (indicated by arrows). These alterations were less marked in dogs treated with sodium nitrite, 24 h previously. (B) This shown data obtained from mitochondria positioned in the IMF region. Compared to the SC dogs, the mitochondrial area, perimeter and Feret-diameter were significantly reduced, whereas the mitochondrial roundness was markedly increased in the IC dogs. These alterations were significantly less marked following the administration of sodium nitrite. Values are means ± S.E.M. ^*P < 0.05 compared with SC; ^#P < 0.05 compared with IC.