Multi-photon microscopic evaluation of saphenous vein endothelium and its preservation with a new solution, GALA Hemant S Thatte, PhD, Kunda S Biswas, MD, Samer F Najjar, MD, Vladimir Birjiniuk, MD, Michael D Crittenden, MD, Thomas Michel, MD, PhD, Shukri F Khuri, MD The Annals of Thoracic Surgery Volume 75, Issue 4, Pages 1145-1152 (April 2003) DOI: 10.1016/S0003-4975(02)04705-7
Fig 1 This figure illustrates changes in structural integrity of vein segments stored in different preservation solutions. Vein segments were stored in heparinized lidocaine saline (HLS), autologous heparinized blood (AHB), tissue culture medium (TCM) for 60 minutes; and in Hank’s balanced salt solution (HBSS) and the newly designed glutathione, ascorbic acid, and L-arginine (GALA) preservation solution for a total of 24 hours. Green fluorescence indicates cell viability; red fluorescence indicates compromised cells. Extensive cell membrane damage and compromised endothelial cell integrity in the vessels was observed after short-term storage in HLS, AHB, and TCM. Cell viability was well preserved in veins during short-term storage in HBSS but resulted in cell death upon extended storage. In contrast, endothelial cells remained viable in vessels preserved in GALA solution throughout the extended time of storage. Representative image, at ×400 magnification, n = 9. (EC = endothelial cells.) The Annals of Thoracic Surgery 2003 75, 1145-1152DOI: (10.1016/S0003-4975(02)04705-7)
Fig 2 Transverse sections of the saphenous veins imaged using multiphoton microscopy in transmission mode. The segments were imaged using XYZ scanning ∼100-μm deep from the site of excision. The vessel lumen, endothelial cell layer, and smooth muscle layer are clearly visible. Endothelial and smooth muscle cell damage was observed in segments stored for 60 minutes in heparinized lidocaine saline (HLS) and autologous heparinized blood (AHB). Structural integrity of the vessel was well preserved in vessels stored in glutathione, ascorbic acid, and L-arginine (GALA). Representative image at ×400 magnification, n = 9. The Annals of Thoracic Surgery 2003 75, 1145-1152DOI: (10.1016/S0003-4975(02)04705-7)
Fig 3 Bradykinin mediated calcium mobilization and nitric oxide generation in saphenous veins stored in glutathione, ascorbic acid, and L-arginine. Segments (similar to those illustrated in Fig 2) were labeled with calcium orange and diaminofluorescein, stimulated with bradykinin and imaged using multiphoton microscopy. A robust two- to threefold increase in calcium (red) and nitric oxide (green) fluorescence signal in the endothelial region was observed 10 minutes after bradykinin stimulation, that found to colocalize (orange-yellow fluorescence). Representative image of nine independent experiments. The Annals of Thoracic Surgery 2003 75, 1145-1152DOI: (10.1016/S0003-4975(02)04705-7)
Fig 4 Vein segments were stored in preservative solutions for various time points, then incubated with diaminofluorescein (DAF) to measure nitric oxide generation. The integrated DAF fluorescence intensity in the endothelial region of each vein was quantitated using multi-photon microscopy after a 10-minute treatment with bradykinin (10 μmol/L) and was then normalized to the fluorescence intensity measured before the drug treatment (dashed line = 1). Each bar represents the mean ± SEM of independent experiments (n = 9). Nitric oxide generation was severely impaired in veins stored in heparinized lidocaine saline (shaded bars), autologous heparinized blood (black-spotted bars), and tissue culture medium (white-spotted bars). Nitric oxide production was maintained in vessels during short-term storage in Hank’s balanced salt solution (black bars); however, a temporal decrease in endothelial nitric oxide synthase (eNOS) activity was observed. In contrast, eNOS activation and nitric oxide generation was well preserved in vessels stored in glutathione, ascorbic acid, and L-arginine (GALA) solution (white bars). A sustained increase in nitric oxide production was observed during extended storage of the vessels in GALA. The Annals of Thoracic Surgery 2003 75, 1145-1152DOI: (10.1016/S0003-4975(02)04705-7)
Fig 5 In-depth imaging of a saphenous vein segment stored in GALA solution using multi-photon microscopy. The vein was imaged at 4-μm steps along the Z axis, and the figure is a representative montage of two-dimensional images taken at depths mentioned in the figure. Green fluorescence indicates living cells; red fluorescence indicates dead cells. The smooth muscle cell layer (SMC; adventitia/media) is identifiable starting at ∼4 μm; vessel lumen and endothelial cell layer becomes clearly visible at ∼120 μm. This figure illustrates that the cell viability was well maintained throughout the vessel stored in GALA for 1440 minutes. ×400 magnification. The Annals of Thoracic Surgery 2003 75, 1145-1152DOI: (10.1016/S0003-4975(02)04705-7)