The effect of short-term exposure to carbon monoxide on platelet stickiness

Prolonged exposure to carbon monoxide accelerates the development of atheroma in rabbits owing to intimal accretion of platelets and fibrin and intramural lipid accumulation (Wanstrup, Kjeldsen, and Astrup, 1967; Birnstingl, Hawkins, and McEwen, 1970). A group of 7 rabbits was exposed in a closed chamber to an atmosphere containing 400 p.p.m. CO for 6-14 hours on several occasions. Platelet stickiness was estimated by a modified Hellem's glass-bead method immediately after exposure and on the following day, for comparison with values in the resting period prior to exposure. There was a highly significant increase in platelet stickiness immediately after exposure to CO, followed the next day by a significant fall below the pre-exposure value. The increase in platelet stickiness after CO exposure may provide a link between tobacco smoking and peripheral vascular disease.