Nicotine induces vasa vasorum stenosis in the aortic wall

ABSTRACT

Abdominal aortic aneurysm (AAA) is a vascular disease that involves aortic wall dilation. Cigarette smoking is an established risk factor and rupture, and nicotine may be a major contributor to the onset of AAA. In humans the condition is associated with stenosis of the vasa vasorum (VV), which may be caused by nicotine. In this study, we evaluated the effects of nicotine on VV pathology. After 4 weeks of nicotine administration to rats using an osmotic pump, the VV patency rate in the nicotine administration group was significantly lower than that in the control group. The levels of Ki-67, a cell proliferation marker, were significantly increased in the regions containing VV in the nicotine group, as were hypoxia inducible factor-α levels. Collagen levels around VV were significantly lower in the nicotine group than in the controls. Our data suggest that nicotine can cause VV stenosis by inducing abnormal proliferation of smooth muscle cells in the VV. The increased risk of AAA development due to cigarette smoking may be partially explained by nicotine-induced VV denaturation and collagen fiber degradation.

KEYWORDS:

• Abdominal aortic aneurysm
• nicotine
• hypoperfusion
• hypoxia
• vasa vasorum

Acknowledgements

This work was supported by Grant-in-Aid for Scientific Research (B) (21H02147) from the Japan Society for the Promotion of Science, and 2020 Kindai University Research Enhancement Grant (KD2004) (to N.Z.).

Disclosure statement

The authors declare no conflict of interest.

Additional information

Funding

This work was supported by the JSPS KAKENHI [21H02147]; 2020 Kindai University Research Enhancement Grant [KD2004].