NADPH-diaphorase expression of endothelial cells during four weeks' healing of a stretch-ePTFE graft: an experimental porcine study.
Endothelial Nitric Oxide Synthase (eNOS) mediates the conversion of L-argine to NO and citrulline, which requires Nicotinamide Adenine Dinucleotide Phosphate (NADPH) as an essential cofactor. Evidence has been given that NOS accounts for the NADPH-diaphorase activity. The aim of the present study was to identify the histochemical and immunocytochemical appearance of NADPH-diaphorase and von Willebrand factor (factor VIII) respectively, in endothelial cells (ECs) during healing of stretch-expanded polytetrafluoroethylene (ePTFE) arterial grafts. On six Swedish domestic pigs an iliac bypass was bilaterally performed using 6 mm stretch-ePTFE grafts. The animals were allowed to survive one, two or four weeks. After explanation the grafts were prepared for NADPH-diaphorase histochemistry and factor VIII immunohistochemistry. Positive staining for the two identification markers was demonstrated after two weeks, whereas a more intense staining was seen after four weeks at the proximal and distal anastomoses, indicating maturation by time. No stained cells were observed at the mid-region of the grafts at any time. The cells differed from normal ECs, the former being less intense which may reflect immature ECs and probably a decreased expression of NO. In conclusion, the present study suggests tha NADPH-d histochemistry can be used to identify ECs. Whether a lower expression of NO compared to normal cells also means a reduced function, capable of causing adverse events has to be further evaluated.
Swartbol
P
P
Department of Surgery and Zoology, Lund University, Sweden.
Johansson
K
K
Pärsson
H
H
Norgren
L
L
D000818:Animals; D001807:Blood Vessel Prosthesis; D004730:Endothelium, Vascular / Q000737:chemistry* / Q000166:cytology; D005169:Factor VIII / Q000032:analysis; D006651:Histocytochemistry; D007150:Immunohistochemistry; D009252:NADPH Dehydrogenase / Q000032:analysis*; D011138:Polytetrafluoroethylene; D013552:Swine; D014945:Wound Healing
D005169:Factor VIII; D011138:Polytetrafluoroethylene; D009252:NADPH Dehydrogenase