The effect has been studied of sodium cromoglycate (SCG) on the activity of ‘C’ fibre sensory nerve endings in the canine lung. Pretreatment with SCG (100 μg/kg i.v.) reduced the excitation of these endings by capsaicin (10 μg/kg i.v.) for approximately 45 min. This property of SCG may explain its ability to suppress certain types of bronchoconstrictor responses in man.

A review is presented of the scientific literature on the effects of sugars (mono- and disaccharides), when used as tobacco additives, on the formation of acetaldehyde in mainstream (MS) smoke and the potential bioavailablity of MS smoke acetaldehyde derived from sugars to the smoker. The experimental data supports the following conclusions. Sugars, e.g., D-glucose, D-fructose, and sucrose, do not produce greater yields of acetaldehyde in MS smoke than are produced from tobacco itself on a weight-for-weight basis. A variety of studies suggests that natural tobacco polysaccharides, including cellulose, are the primary precursors of acetaldehyde in MS smoke. In a number of different studies using commercial cigarette brands, MS smoke yields of acetaldehyde correlate (r > 0.9) with both MS smoke "tar" and carbon monoxide. MS smoke acetaldehyde yields are affected more by cigarette design characteristics that influence total smoke production, such as filter ventilation, filtration, and paper porosity, than by reducing sugars. MS smoke acetaldehyde deposits primarily in the upper respiratory tract, including the mouth, of the smoker. Acetaldehyde is rapidly metabolized by aldehyde dehydrogenase in the blood and elsewhere in the body, including at the blood-brain barrier. Tobacco sugar-derived MS smoke acetaldehyde from commercial cigarettes is unlikely to result in direct central nervous system effects on the smoker.

No abstract

The analysis of spent cigarette filters enables the estimation of the nicotine and tar (nicotine-free dry particulate matter) yields obtained by smokers in their everyday environment and has been shown to correlate well with biomarkers of exposure. Leading products across the range of ISO tar yields were selected from Australia, Brazil, Canada, Germany, Japan, New Zealand, South Africa and Switzerland. At least fifty demographically representative smokers were recruited per product. Subjects, ≥ 21 years of age and smoking ≥ 5 cigarettes per day, were asked to collect ≥ 15 filters from cigarettes they had smoked. The collected filters were analysed for nicotine and UV absorbance to enable the smokers' mouth level exposure to nicotine and tar to be estimated and a comparison of countries and tobacco blend styles to be made. Smoking history data were also collected. More than 80,000 filters were collected from 5703 smokers of 106 products from eight countries. Mean ± SD estimated nicotine exposures per cigarette and per day ranged from 0.93 ± 0.34 mg/cigarette (Brazil) to 1.77 ± 0.69 mg/cigarette (South Africa) and from 16.4 ± 11.1mg/day (Germany) to 31.5 ± 14.8 mg/day (South Africa), respectively. Male smokers obtained higher mean estimated tar and nicotine exposures than female smokers. These gender differences were statistically significant for six countries. Significant correlations were found between estimated nicotine exposure and ISO nicotine yield, and between estimated tar exposure and ISO tar yield (p<0.001).