Water-pipe tobacco smoking is becoming prevalent in all over the world including Western countries. There are limited data on the cardiovascular effects of water-pipe smoke (WPS), in particular following chronic exposure. Here, we assessed the chronic cardiovascular effects of nose-only WPS exposure in C57BL/6 mice. The duration of the session was 30 min/day, 5 days/week for six consecutive months. Control mice were exposed to air. WPS significantly increased systolic blood pressure. The relative heart weight and plasma concentrations of troponin-I and B-type natriuretic peptide were increased in mice exposed to WPS. Arterial blood gas analysis showed that WPS caused a significant decrease in PaO2 and an increase in PaCO2. WPS significantly shortened the thrombotic occlusion time in pial arterioles and venules, and increased the number of circulating platelet. Cardiac lipid peroxidation, measured as thiobarbituric acid-reactive substances, was significantly increased, while those of superoxide dismutase activity, total nitric oxide activity and glutathione concentration were reduced by WPS exposure. Likewise, immunohistochemical analysis of the heart revealed an increase in the expression of inducible nitric oxide synthase and cytochrome C by cardiomyocytes of WPS-exposed mice. Moreover, hearts of WPS-exposed mice showed the presence of focal interstitial fibrosis. WPS exposure significantly increased heart DNA damage assessed by Comet assay. We conclude that chronic nose-only exposure to WPS impairs cardiovascular homeostasis. Our findings provide evidence that long-term exposure to WPS is harmful to the cardiovascular system and supports interventions to control the spread of WPS, particularly amid youths.
- Water-pipe smoke
- Chronic nose-only exposure
- Blood gas
- oxidative stress
- Copyright © 2016, American Journal of Physiology-Heart and Circulatory Physiology