Effect of smoking on different biological parameters in aging mice

To investigate the harmful effect of smoking three groups of CBA/Ca male mice of different ages were subjected to smoking for different time durations. Body weight changes and acute cold tolerance were measured throughout the experiment. Thyroid hormone levels (T4, T3), TSH and lipid peroxidation products (as malondialdehyde and lipofuscin) were determined from either the blood or some organs. There was a decrease in body weight related to aging and it was most pronounced in the oldest animals (Group III). However, significant body-weight loss due to smoking was found in the youngest animals (Group I). Similarly, smoking resulted in a body-weight loss of the other two older groups (Groups II and III) as well. The greatest change in withstanding cold stress was measured in Group I and less so in Group II, as a consequence of smoking. Simultaneously, the youngest animals (Group I) showed the most remarkable changes in thyroxine (T4) and 3,3,4-triiodothyronine (T3) serum concentrations. Both hormone levels were significantly lower in the smokers. The T3 serum levels of the oldest animals (Group III) did not differ, while the T4 levels apparently increased. The TSH blood level in the oldest group was lower (by 20%) in the smokers compared to controls. Malondialdehyde (MDA) and lipofuscin content in most of the organs were considerably higher in the aging animals than those of the younger ones. The most significant elevations of these lipid peroxidation products were found in the smokers compared to the age-matched controls. The present results indicate that smoking probably accelerates the aging process.