Secondhand Smoke Exposure in Aging-related Cardiac Disease

Exposure to secondhand smoke (SHS) exposure is increased the risk of heart disease included atherosclerosis and coronary disease. Aging is a physiology process involving progressive impairment of normal heart functions, due to an increasing vulnerability, which reduces the ability of survive. However, it is not clear pathological condition in aging exposure to SHS. The aim of this study was to examine SHS exposure in aging-related disease. The rats were placed in SHS exposure chamber and exposed to 10 cigarettes for 30 min, twice a day, 5 days/ one week for 1 month. After 4 weeks secondhand smoke exposure, rats left ventricular (LV) underwent morphological and function study with echocardiography. Histopathology of left ventricular sections were stained with Hematoxylin-Eosin staining and related left ventricular hypertrophy protein expression levels by Western blot analysis. After 4 weeks SHS exposure, LV weight showed significant increased. On the other hand, from echocardiography result, we found EF (%) and FS (%) were apparently decreased in aging SHS exposure. IVS, LVID and LVPW at diastolic diameters were increased in aging SHS exposure. However, in aging systolic diameters always preserved. Here we did not show that. Moreover, we observed enlargement morphology of the LV and LV well thickness of increase. In addition, we found LV hypertrophy marker protein, calcineurin/NFATc4, was only increased in aging and aging SHS exposure. Our study suggests that SHS exposure and aging will altercate left ventricular hypertrophy.