Myocardial Morphology in Rabbits Exposed to Various Gas-Phase Constituents of Tobacco Smoke

Rabbits were continuously exposed to 200 ppm carbon monoxide. Using the same criteria as applied by earlier investigators for morphological myocardial damage, no histotoxic effect on myocardial morphology could be demonstrated when electron-microscopic investigations were performed blindly. Similarly, exposure to 0.5 ppm hydrogen cyanide, 0.5 ppm hydrogen cyanide + 200 ppm carbon monoxide, 0.5 ppm hydrogen cyanide + 200 ppm carbon monoxide + 5 ppm nitric oxide and to 50 ppm carbonyl sulphide for 1-7 weeks had no significant effect on myocardial ultrasturcture.