A new HMG-CoA reductase inhibitor, pitavastatin remarkably retards the progression of high cholesterol induced atherosclerosis in rabbits.
BACKGROUND
The remarkable anti-atherosclerotic effects of 3-hydroxy-3-methyl-glutaryl-CoA reductase inhibitor have not been demonstrated in diet induced severe hyperlipidemia in rabbit model.


OBJECTIVE
We have investigated the effect of pitavastatin, a newly developed statin, on atherosclerosis in rabbits.


RESULTS
Oophorectomized female NZW rabbits were fed 0.3% cholesterol chow for 12 weeks with or without pitavastatin (0.1mg/kg per day) (Gp.NK and HCD). The level of serum cholesterol was decreased in Gp.NK compared with Gp.HCD (772.8 +/- 70.2 versus 1056.9 +/- 108.3 mg/d), whereas no significant alterations were observed in triglyceride and HDL-cholesterol. NO dependent response stimulated by acetylcholine and calcium ionophore A23187 and tone related basal NO response induced by N(G)-monomethyl-l-arginine acetate were all improved by pitavastatin treatment. Pitavastatin treatment increased the level of cyclic GMP in the aorta of cholesterol fed rabbits. In the aorta, the expression of eNOS mRNA was significantly up regulated and O(2)(-) production was slightly reduced in Gp.NK animals. Atherosclerotic area was significantly decreased in aortic arch and thoracic aorta from Gp.NK compared with those from Gp.HCD ( 15.1 +/- 5.3 versus 41.9 +/- 10.2%, 3.1 +/- 1.1versus 7.9 +/- 1.2% in Gp.NK and Gp.HCD aortic arch and thoracic aorta). Anti-macrophage staining area, the MMP1 or 2 and the nitrotyrosine positive area were decreased in Gp.NK.


CONCLUSIONS
Pitavastatin retards the progression of atherosclerosis formation and it improves NO bioavailability by eNOS up-regulation and decrease of O(2)(-).
Hayashi
Toshio
T
Department of Geriatrics, Nagoya University Graduate School of Medicine, 65 Tsuruma-cho, Showa-ku Nagoya City 466-8550, Japan. hayashi@med.nagoya-u.ac.jp
Rani P
Juliet Arockia
JA
Fukatsu
Akiko
A
Matsui-Hirai
Hisako
H
Osawa
Masako
M
Miyazaki
Asaka
A
Tsunekawa
Taku
T
Kano-Hayashi
Hatsuyo
H
Iguchi
Akihisa
A
Sumi
Daigo
D
Ignarro
Louis J
LJ
D000284:Administration, Oral; D000818:Animals; D001161:Arteriosclerosis / Q000188:drug therapy* / Q000503:physiopathology* / Q000662:veterinary; D001682:Biological Availability; D008076:Cholesterol, HDL / Q000097:blood; D004195:Disease Models, Animal; D018450:Disease Progression; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005260:Female; D009569:Nitric Oxide / Q000494:pharmacology; D011804:Quinolines / Q000494:pharmacology*; D011817:Rabbits; D014280:Triglycerides / Q000097:blood; D015854:Up-Regulation
D008076:Cholesterol, HDL; D004791:Enzyme Inhibitors; D011804:Quinolines; D014280:Triglycerides; D009569:Nitric Oxide; C108475:pitavastatin