Effect of cigarette smoking on endothelial permeability of rat large arteries. A light and electronmicroscopic study

Effect of cigarette smoking on endothelial permeability of rat large arteries. A light and electronmicroscopic study

16 EVALUATION OF ISCHEMIC AREAS IN CARDIAC TISSUE BY FLUORESCENCE SPECTROSCOFY. C.H. Barlow, A.H. Harken and B. Chance. Johnson Research Foundatian a...

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EVALUATION OF ISCHEMIC AREAS IN CARDIAC TISSUE BY FLUORESCENCE SPECTROSCOFY. C.H. Barlow, A.H. Harken and B. Chance. Johnson Research Foundatian and Harrison Department of Surgical Research, University of Pennsylvania, Philadelphia, Pennsylvania, U.S.A. 1917h. Reduced pyridine nucleotides (NADH) and oxidized flavoproteins (FP) are intrinsic components of living tissues and have fluorescence properties which may be used to evaluate the mitochondrial redox state of tissue. The ischemie area of the epicardlum of blood free perfused rat and rabbit hearts following coronary artery occlusion has been measured utilizing NADH flash fluorescence photography. Three dimensional fluorescence measurements of hearts were performed by freezing the hearts, sequentially removing layers of tissue and recording the NADH fluorescence photo~raphieally or scanning both the FP and NADH fluorescences and displaying an image of the FP/NADH ratio. These studies have now been extended to hearts of larger mammals in situ to evaluate the effects of blood and species upon the nature of the border zone surrounding a coronary infarct. In the in sltu dog heart as well as in perfused rat and rabbit hearts the transition from tissue with normal aerobic NADH fluorescence levels to ischemic areas with maximal ~ D H fluorescence occurs within i00 microns. However, in contrast to rat and rabbit hearts which normally exhibit a single ischemlc zone following coronary artery occlusion, the dog heart exhibits a central area which is composed almost entirely of ischemlc tissue surrounded by an area which appears as a patchwork of ischemic and normoxie tissues which share sharp interfaces. (Supported by USPHS Grants HL-18{O8 and HL-17826. )

EFFECT OF CIGARETTE SMOKING ON ENDOTHELIAL PERMEABILITY OF RAT LARGE ARTERIES. A LIGHT AND ELECTRONMICROSCOPIC STUDY. M. Bazin, M. Boutet, N . D . Huy and P.E. Roy. Ste-Foy, Quebec, Canada. Using the fine structural tracer horseradish peroxidase (HRP), the permeability of carotid artery and thoracic aorta was studied in 16 male Sprague Dawley rats (,u 300 g). Eight rats were exposed daily, for 14 days to cigarette smoke (2 cigarettes a day) with a smoking machine. Four rats were introduced daily into the smoking machine but were not expa6ed to cigarette smoke. Four rats served as absolute controls. Under light ether anesthesia, the systemic arterial blood pressure was measured by right carotid artery cannulation and was similar in all experimental groups. The protein tracer (HRP) was iniected intravenously at a dose of 10 mg/100 gm body weight sixty seconds before animal sacrifice by aldehyde perfusion fixation. Carotid artery and thoracic aorta subendothelium of absolute control rats was devoid of reaction product. Few pinocytotio vesicles and intercellular clefts contained HRP reaction product. Morphological observations were slightly exagerated in rats exposed to the smoking machine. Rats exposed to cigarette smoke showed an important increased endothelial permeability. A stronger and more diffuse HRP reaction product was located in the subendothelial space, sometimes extending deeper in the arterial wall through fenestration of elastic lamina. These resulfs suggest that cigarette smoking, either by catecholamine liberation, carbon monoxyde inhalation or other mechanism, increases rat endothelial permeability of large arteries. (Supported by a grant of the Can. Heart Foundation).