Figure 2A-2F.

Chronic nicotine treatment does not alter adventitial fat and endothelium function or smooth muscle contraction, but specifically enhances smooth muscle relaxation in rat aortas. Aortic morphometry: (A) Relative periaortic fat weight and aortic weight (n=13–16); (B) Periaortic fat area and wall area (n=5–6); Representative images of partial aortic arch and descending thoracic aorta (C) as well as aortic HE-stained sections (D) showing reduced periaortic fat after 6 weeks of nicotine treatment. (E) Aortic contraction induced by a single dose of phenylephrine (Phe, 3×10⁻⁷ mol/L). (F) Dose-response curve of acetylcholine (ACh)-induced aortic relaxation. Sal, saline group; Nic, nicotine group; F+E+, both adventitial fat and endothelium intact; F−E+, adventitial fat removed and endothelium intact. Data are shown as mean±SEM. ^bP<0.05, ^cP<0.01. Scale bars, 1 mm (D).