title: Use of the HET-CAM Test for the Determination of the Irritant Potential of Cigarette Sidestream Smoke.
abstract: We investigated the suitability of the HET-CAM test for the determination of the irritant potential of cigarette sidestream smoke (SS). Coded test solution (0.2ml) was applied to the chorioallantoic membrane (CAM) of 10 day-old White Leghorn chick embryos. The time from the start of exposure to the occurrence of blood vessel injection (I), haemorrhage (H) and coagulation (C) in the first 5 minutes was recorded, and irritancy scores (IS) from 0 to 21 were calculated (Luepke, 1985). For the microbicide Kathon CG((R)) as positive control, a dose-dependent increase in irritancy between 0.3 and 15g/litre was seen (IS up to 17). Mainstream smoke (MS) or fresh SS from the Reference Cigarette 2R1 was passed through phosphate buffered saline (PBS) in a glass impinger. MS-PBS concentrations between 1.7 and 10 puffs/ml elicited IS from 4.5 to 9. SS-PBS concentrations between 4.5 and 15 puffs/ml elicited IS from 3 to 7.5, an underestimation due to mortality associated with an immediate breakdown of blood circulation through the CAM vessels, thereby interfering with the irritation parameters I and H. We propose to test blood circulation-independent irritation endpoints, for example trypan blue uptake in the CAM (INVITTOX/ERGATT/FRAME, 1996), for determination of the irritancy of SS.
authors.affiliation: INBIFO Institut für biologische Forschung, Fuggerstr. 3, 51149, Köln, Germany.
authors.forename: W K
authors.initials: WK
authors.lastname: Schlage
authors.forename: H
authors.initials: H
authors.lastname: Bülles
authors.forename: B
authors.initials: B
authors.lastname: Kurkowsky