This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Foster, T. H. Articles by Sporn, L. A. Search for Related Content PubMed PubMed Citation Articles by Foster, T. H. Articles by Sporn, L. A.

Photosensitized Release of von Willebrand Factor from Cultured Human Endothelial Cells¹

Departments of Radiology [T. H. F.], Medicine, Hematology Unit [M. C. P., V. J. M., L. A. S.], and Biochemistry [R. H.], University of Rochester School of Medicine and Dentistry, Rochester, New York 14642

Cultured endothelial cells from the human umbilical vein were incubated with low concentrations (1 µg/ml) of the photosensitizer Photofrin II. Following a sublethal light exposure, a light dose-dependent release of von Willebrand factor (vWf) into the culture medium was observed. Analysis of the multimeric composition of the released protein indicated that it originated from the intracellular pool of large vWf multimers stored in the Weibel-Palade bodies. This release was detected as early as 1 h postirradiation. Release was inhibited at low temperature and was dependent upon the presence of extracellular calcium. Photosensitization resulted in an influx of calcium whose time course paralleled vWf release from the cells. Since vWf mediates platelet adhesion to the vascular subendothelium, it is possible that its photochemically stimulated release in vivo could contribute to platelet thrombus formation observed in tissue following photodynamic therapy.

¹ The research presented in this report was supported by USPHS Grants CA36856, HL07152, HL43711, and HL30616 awarded by the National Cancer Institute and the National Heart, Lung and Blood Institute.

² Supported in part by the Department of Radiology at the University of Rochester. To whom requests for reprints should be addressed, at University of Rochester School of Medicine and Dentistry, Department of Radiology, Box 648, 601 Elmwood Avenue, Rochester, NY 14642.

Received 12/ 4/90. Accepted 4/ 9/91.

This article has been cited by other articles:

				A. Matsubara, T. Nakazawa, D. Husain, E. Iliaki, E. Connolly, N. A. Michaud, E. S. Gragoudas, and J. W. Miller Investigating the effect of ciliary body photodynamic therapy in a glaucoma mouse model. Invest. Ophthalmol. Vis. Sci., June 1, 2006; 47(6): 2498 - 2507. [Abstract] [Full Text] [PDF]

				B. Chen, B. W. Pogue, J. M. Luna, R. L. Hardman, P. J. Hoopes, and T. Hasan Tumor Vascular Permeabilization by Vascular-Targeting Photosensitization: Effects, Mechanism, and Therapeutic Implications Clin. Cancer Res., February 1, 2006; 12(3): 917 - 923. [Abstract] [Full Text] [PDF]

				P. Beaumont, C. S. Lim, A. Chang, and K. Kang Acute Severe Vision Decrease Immediately After Photodynamic Therapy Arch Ophthalmol, October 1, 2004; 122(10): 1546 - 1547. [Full Text] [PDF]

				W. R. Chen, H. Liu, J. W. Ritchey, K. E. Bartels, M. D. Lucroy, and R. E. Nordquist Effect of Different Components of Laser Immunotherapy in Treatment of Metastatic Tumors in Rats Cancer Res., August 1, 2002; 62(15): 4295 - 4299. [Abstract] [Full Text] [PDF]