Possible mechanisms involved in the effect of the subchronic administration of rosuvastatin on endothelial function in rats with metabolic syndrome

Metabolic syndrome is a multifaceted condition associated with a greater risk of various disorders (e.g., diabetes and heart disease). In a rat model of metabolic syndrome, an acute in vitro application of rosuvastatin causes relaxation of aortic rings. Since the outcome of a subchronic rosuvastatin treatment is unknown, the present study explored its effect on acetylcholine-induced vasorelaxation of aortic rings from rats with metabolic syndrome. Animals were submitted to a 16-week treatment, including a standard diet, a cafeteria-style diet (CAF-diet), or a CAF-diet with daily rosuvastatin treatment (10 mg/kg). After confirming the development of metabolic syndrome in rats, aortic segments were extracted from these animals (those treated with rosuvastatin and untreated) and the acetylcholine-induced relaxant effect on the corresponding rings was evaluated. Concentration-response curves were constructed for this effect in the presence/absence of L-NAME, ODQ, KT 5823, 4-aminopyridine (4-AP), tetraethylammonium (TEA), apamin plus charybdotoxin, glibenclamide, indomethacin, clotrimazole, and cycloheximide pretreatment. Compared to rings from control rats, acetylcholine-induced vasorelaxation decreased in rings from animals with metabolic syndrome, and was maintained at a normal level in animals with metabolic syndrome plus rosuvastatin treatment. The effect of rosuvastatin was inhibited by L-NAME, ODQ, KT 5823, TEA, apamin plus charybdotoxin, but unaffected by 4-AP, glibenclamide, indomethacin, clotrimazole, or cycloheximide. In conclusion, the subchronic administration of rosuvastatin to rats with metabolic syndrome improved the acetylcholine-induced relaxant response, involving stimulation of the NO/cGMP/PKG/Ca2+-activated K+ channel pathway.

Effects of Rosuvastatin on Apolipoprotein J in Balloon-Injured Carotid Artery in Rats / Efeitos da Rosuvastatina sobre Apolipoproteína J em Artérias de Ratos Lesionadas com Balão

Abstract Background: Restenosis after percutaneous coronary intervention in coronary heart disease remains an unsolved problem. Clusterin (CLU) (or Apolipoprotein [Apo] J) levels have been reported to be elevated during the progression of postangioplasty restenosis and atherosclerosis. However, its role in neointimal hyperplasia is still controversial. Objective: To elucidate the role Apo J in neointimal hyperplasia in a rat carotid artery model in vivo with or without rosuvastatin administration. Methods: Male Wistar rats were randomly divided into three groups: the control group (n = 20), the model group (n = 20) and the statin intervention group (n = 32). The rats in the intervention group were given 10mg /kg dose of rosuvastatin. A 2F Fogarty catheter was introduced to induce vascular injury. Neointima formation was analyzed 1, 2, 3 and 4 weeks after balloon injury. The level of Apo J was measured by real-time PCR, immunohistochemistry and western blotting. Results: Intimal/medial area ratio (intimal/medial, I/M) was increased after balloon-injury and reached the maximum value at 4weeks in the model group; I/M was slightly increased at 2 weeks and stopped increasing after rosuvastatin administration. The mRNA and protein levels of Apo J in carotid arteries were significantly upregulated after rosuvastatin administration as compared with the model group, and reached maximum values at 2 weeks, which was earlier than in the model group (3 weeks). Conclusion: Apo J served as an acute phase reactant after balloon injury in rat carotid arteries. Rosuvastatin may reduce the neointima formation through up-regulation of Apo J. Our results suggest that Apo J exerts a protective role in the restenosis after balloon-injury in rats.

Resumo Fundamento: A reestenose após intervenção coronária percutânea (ICP) após doença coronariana continua um problema não solucionado. Estudos relataram que os níveis de clusterina (CLU), também chamada de apolipoproteína (Apo) J, encontram-se elevados na progressão da reestenose pós-angioplastia e na aterosclerose. Contudo, seu papel na hihperplasia neointimal ainda é controverso. Objetivo: Elucidar o papel da Apo J na hiperplasia neointimal na artéria carótida utilizando um modelo experimental com ratos in vivo, com e sem intervenção com rosuvastatina. Métodos: ratos Wistar machos foram divididos aleatoriamente em três grupos - grupo controle (n = 20), grupo modelo (n = 20), e grupo intervenção com estatina (n = 32). Os ratos no grupo intervenção receberam 10 mg/kg de rosuvastatina. Um cateter Fogarty 2 F foi introduzido para induzir lesão vascular. A formação de neoíntima foi analisada 1, 2, 3 e 4 semanas após lesão com balão. Concentrações de Apo J foram medidas por PCR em tempo real, imuno-histoquímica e western blotting. Resultados: A razão área íntima/média (I/M) aumentou após a lesão com balão e atingiu o valor máximo 4 semanas pós-lesão no grupo modelo; observou-se um pequeno aumento na I/M na semana 2, que cessou após a administração de rosuvastatina. Os níveis de mRNA e proteína da Apo J nas artérias carótidas aumentaram significativamente após administração de rosuvastatina em comparação ao grupo modelo, atingindo o máximo na semana 2, mais cedo em comparação ao grupo modelo (semana 3). Conclusão: A Apo J atuou como reagente de fase aguda após lesão com balão nas artérias carótidas de ratos. A rosuvastatina pode reduzir a formação de neoíntoma por aumento de Apo J. Nossos resultados sugerem que a Apo J exerce um papel protetor na reestenose após lesão com balão em ratos.