Pertussis toxin (PTX) attenuates isoflurane-dependent caveolae formation and impacts mitochondrial morphology. Control (A), isoflurane (B), PTX + control (C), and PTX + isoflurane (D) treated mice were allowed 15 min washout after isoflurane/oxygen exposure. Animals were perfusion fixed, and hearts were processed for electron microscopy analysis. Isoflurane increased membrane invaginations consistent with caveolae (white arrowheads, B), and this was blocked with PTX. PTX treatment resulted in loss of mitochondrial structure in control and isoflurane groups (asterisk and arrows represent altered mitochondrial morphology and potential mitophagy, respectively).