Assessing Photofrin uptake in atherosclerosis with a fluorescent probe: comparison with photography and tissue measurements.
The purpose of this study was to assess Photofrin porfimer sodium (P*) concentration in atherosclerotic plaque (ASP) using a fluorescence detector (Fluoroprobe) compared with fluorescent photography and chemical extraction of P*. ASP was created in the aortoiliac segments of Yucatan miniswine by a combination of balloon endothelial injury and 2% cholesterol and 15% lard diet for 7 weeks. At that time, swine were given P* I.V. in one of the following single dosages: Group I, 2.5; Group II, 1.0; or Group III, 0.5 mg/kg. Swine were sacrificed 24 hours later and aortoiliac and control carotid artery segments removed. Fluorescence was determined from these segments using photographic techniques, the Fluoroprobe, and a spectrofluorometer after chemical extraction. ASP were identified in all swine using photography and the Fluoroprobe. The intensity of fluorescence measured with the Fluoroprobe for Groups I to III was 1,098 +/- 524, 471 +/- 337, and 295 +/- 173 units, respectively (P < 0.01). The tissue concentration of P* in ASP from each group was 130.4 +/- 82.7, 10.0 +/- 1.2, and 9.1 +/- 0.6 ng/g, respectively (P < 0.01). There was a linear correlation between the fluorescence intensity measured with the Fluoroprobe and the extracted tissue concentration (r = 0.88, P < 0.0001). This study showed that a fluorescent detector such as the Fluoroprobe accurately detects the uptake of P* into atherosclerotic plaque.
Hsiang
Y
Y
Department of Surgery, University of British Columbia, Vancouver, Canada.
Stonefield
M
M
Bower
R D
RD
Fragoso
M
M
Tsang
V
V
Crespo
M T
MT
Lundkvist
A
A
D000818:Animals; D001018:Aortic Diseases / Q000378:metabolism / Q000473:pathology; D001161:Arteriosclerosis / Q000378:metabolism* / Q000473:pathology*; D005260:Female; D005453:Fluorescence; D017324:Hematoporphyrin Derivative / Q000008:administration & dosage / Q000032:analysis / Q000493:pharmacokinetics*; D007083:Iliac Artery / Q000737:chemistry / Q000378:metabolism / Q000473:pathology; D007275:Injections, Intravenous; D007834:Lasers; D008297:Male; D008856:Microscopy, Fluorescence; D010781:Photography / Q000295:instrumentation / Q000379:methods; D013050:Spectrometry, Fluorescence; D013552:Swine; D013556:Swine, Miniature
D017324:Hematoporphyrin Derivative