Beyond Animal Research
By Jonathan Balcombe, Ph.D.
Animal Smoking Experiments
Scientists like to joke that smoking is a leading cause of statistics. It's an amusing observation, but sadly, when it comes to animal experimentation, it’s all too true. Despite the failure of numerous animal studies during the 1950s and 1960s to reveal a clear link between cigarette smoking and cancer—and despite our established knowledge from human clinical data that smoking is deadly—smoking experiments on animals continue.
A search of the NIH PubMed database reveals dozens of rat and mouse smoking studies published in 2004 alone. Here’s a brief sampling:
- At the University of California, Davis, male mice spent five months in a whole-body inhalation chamber to assess three levels of smoke exposure on lung tumors (Witschi et al. 2004).
- At the Institute of Biological Research and Technology in Athens, Greece, a tobacco smoke carcinogen was forced into rats’ lungs through a tube or by abdominal injection over a 16-week period to explore the interaction between tobacco smoke and asbestos exposure (Loli et al. 2004).
- At Creighton University in Nebraska, rats were exposed to smoke for 12 weeks to observe its effects on their nasal linings (Vent et al. 2004).
- At Slovak Medical University, Slovak Republic, rats were made to inhale fibrous industrial dusts combined with cigarette smoke for six months to see what it did to their lung cells (Cerna et al. 2004).
- A study of 65 rats at Adnan Menderes University in Turkey concluded that exposure to passive cigarette smoke may stunt kidney growth (Dundar et al. 2004).
At least one tobacco company—R.J. Reynolds of Winston-Salem, North Carolina—also continues to tinker away on animal experiments:
- Male and female rats were forced to inhale cigarette smoke five hours per week for 13 weeks to compare two different reference cigarettes (Higuchi et al. 2004).
- Cigarette tar was applied to the skin of female mice (40 per group) over a 29-week period to evaluate a specific test assay, variations of which have been used for decades (Meckley et al. 2004).
- A 13-week smoke inhalation study in rats and a 30-week skin tumor study in mice concluded that cigarettes with or without expanded shredded tobacco stems had similar toxicity (Theophilus et al. 2004).
Many of these experiments appear to be useless attempts to confirm what is already known in humans. Future columns will investigate this possibility and the wealth of available approaches based on clinically relevant human data.
Cerna S, Beno M, Hurbankova M, Kovacikova Z, Bobek P, Kyrtopoulos SA. Evaluation of bronchoalveolar lavage fluid cytotoxic parameters after inhalation exposure to amosite and wollastonite fibrous dusts combined with cigarette smoke. Cent Eur J Public Health. 2004;12 Suppl:S20-3.
Dundar M, Kocak I, Culhaci N. Effects of long-term passive smoking on the diameter of glomeruli in rats: Histopathological evaluation. Nephrology. (Carlton) 2004;9:53-57.
Higuchi MA, Sagartz J, Shreve WK, Ayres PH. Comparative subchronic inhalation study of smoke from the 1R4F and 2R4F reference cigarettes. Inhal Toxicol. 2004;16:1-20.
Loli P, Topinka J, Georgiadis P, Dusinska M, Hurbankova M, Kovacikova Z, Volkovova K, Wolff T, Oesterle D, Kyrtopoulos SA. Benzo[a]pyrene-enhanced mutagenesis by asbestos in the lung of lambda-lacI transgenic rats. Mutat Res. 2004;553:79-90.
Meckley D, Hayes JR, Van Kampen KR, Mosberg AT, Swauger JE. A responsive, sensitive, and reproducible dermal tumor promotion assay for the comparative evaluation of cigarette smoke condensates. Regul Toxicol Pharmacol. 2004;39:135-149.
Theophilus EH, Pence DH, Meckley DR, Higuchi MA, Bombick BR, Borgerding MF, Ayres PH, Swauger JE. Toxicological evaluation of expanded shredded tobacco stems. Food Chem Toxicol. 2004;42:631-639.
Vent J, Robinson AM, Gentry-Nielsen MJ, Conley DB, Hallworth R, Leopold DA, Kern RC. Pathology of the olfactory epithelium: smoking and ethanol exposure. Laryngoscope. 2004;114:1383-1388.
Witschi H, Espiritu I, Uyeminami D, Suffia M, Pinkerton KE. Lung tumor response in strain a mice exposed to tobacco smoke: some dose-effect relationships. Inhal Toxicol. 2004;16:27-32.