PMC

Representative Western-blot of e-NOS (A), COX-1 (B) and COX-2 (C) protein expression in aortic and small mesenteric artery (SMA) segments from adult and old rats. Similar results were obtained in three separate experiments.

Influence of age on relaxation to acetylcholine (ACh) in the aorta (A) and the small mesenteric artery (B) from 12–14, 32 and 70–100-week-old rats. Results are expressed as a relaxation per cent of the initial noradrenaline-induced precontraction level. Data are mean±s.e.mean of 6–14 arterial segments. ^***P<0.001, 12–14 and 32 week versus 70–100-week-old rats.

Effect of the cyclo-oxygenase inhibitor, indomethacin (10 μM), on relaxation to acetylcholine (ACh) in the aorta (A, C) and the small mesenteric artery (B, D) from adult (A, B) and old (C, D) rats. Results are expressed as a relaxation per cent of the initial noradrenaline-induced precontraction level. Data are mean±s.e.mean of 6–7 arterial segments. ^**P<0.01, ^*P<0.05, with versus without indomethacin.

Effect of the selective cyclo-oxygenase-2 inhibitor, NS-398 (1 μM), on relaxation to acetylcholine (ACh) in the aorta (A, C) and the small mesenteric artery (B, D) from adult (A, B) and old (C, D) rats. Results are expressed as a relaxation per cent of the initial noradrenaline (for SMA) or U46619 (for aorta)-induced precontraction level. Data are mean±s.e.mean of 5–6 arterial segments. ^*P<0.05, with versus without NS-398.

Effect of the nitric oxide synthase inhibitor, N^G-nitro-L-arginine (L-NA, 30 μM), on relaxation to acetylcholine (ACh) in the aorta (A, C) and the small mesenteric artery (B, D) from adult (A, B) and old (C, D) rats. Results are expressed as a relaxation per cent of the initial noradrenaline-induced precontraction level. Data are mean±s.e.mean of 6–7 arterial segments. ^***P<0.001, ^**P<0.01, ^*P<0.05, with versus without L-NA.

Effect of the thromboxane A₂/prostaglandin H₂ receptor antagonist, GR 32191 B (3 μM), on relaxation responses to acetylcholine (ACh) in the aorta (A) and the small mesenteric artery (B) from old rats and thromboxane B₂ (TXB₂) production of aortic (C) and SMA (D) rings from old rats exposed to noradrenaline (0.3 μM) and ACh (1 μM). Results are expressed as a relaxation per cent of the initial noradrenaline-induced precontraction level. Data are mean±s.e.mean of 8–9 arterial segments for relaxation experiments and 10 aortic and five SMA rings for TXB₂ determination. ^*P<0.05, with versus without GR 32191 B, ^**P<0.01, adult versus old rats.