Lung Ultrastructure. Effect of H2S on mitochondrial ultrastructure in lung cells, as determined by transmission electron microscopy analysis, in LPS-Induced ALI rat model (original magnification × 25000). There were significant differences in the ultrastructure of mitochondria in lung cells in the control group (control) and LPS injury group (LPS). The mitochondria in lung cells from the LPS group were swollen with disrupted or disintegrated cristae and the osmiophilic lamellar bodies were fusion or disappeared. This mitochondrial damage was lightly mitigated in the LPS + low-dose NaHS group (L), and were significantly mitigated in LPS + middle-dose NaHS group (M) and high-dose NaHS group (H). Arrows indicate mitochondria in lung cells. Bar, 500 nm.