Acetylsalicylic Acid Reduces Passive Aortic Wall Stiffness and Cardiovascular Remodelling in a Mouse Model of Advanced Atherosclerosis

Effects of Long-Term Intervention with Losartan, Aspirin and Atorvastatin on Vascular Remodeling in Juvenile Spontaneously Hypertensive Rats

Hypertension in adolescents is associated with adverse cardiac and vascular events. In addition to lowering blood pressure, it is not clear whether pharmacological therapy in early life can improve vascular remodeling. This study aimed to evaluate the effects of long-term administration of losartan, aspirin, and atorvastatin on vascular remodeling in juvenile spontaneously hypertensive rats (SHRs). Losartan, aspirin, and atorvastatin were administered via gavage at doses of 20, 10, and 10 mg/kg/day, respectively, on SHRs aged 6-22 weeks. Paraffin sections of the blood vessels were stained with hematoxylin-eosin (H&E) and Sirius Red to evaluate the changes in the vascular structure and the accumulation of different types of collagen. The plasma levels of renin, angiotensin II (Ang II), aldosterone (ALD), endothelin-1 (ET-1), interleukin-6 (IL-6), and neutrophil elastase (NE) were determined using ELISA kits. After the 16-week treatment with losartan, aspirin, and atorvastatin, the wall thickness of the thoracic aorta and carotid artery decreased. The integrity of the elastic fibers in the tunica media was maintained in an orderly manner, and collagen deposition in the adventitia was retarded. The plasma levels of renin, ALD, ET-1, IL-6, and NE in the SHRs also decreased. These findings suggest that losartan, aspirin, and atorvastatin could improve vascular remodeling beyond their antihypertensive, anti-inflammatory, and lipid-lowering effects. Many aspects of the protection provided by pharmacological therapy are important for the prevention of cardiovascular diseases in adults and older adults.

Cardioprotective effects of chloroquine pretreatment on ischemic and reperfusion injury via activation of ERK1/2 in isolated rat hearts

PURPOSE

Several therapeutic agents have been found to prevent myocardial ischemic and reperfusion (I/R) injury after cardiac surgery; however, no drug is routinely used to afford cardioprotective benefits in clinical settings. Herein, we aimed to determine whether chloroquine (CQ) pretreatment attenuates I/R injury after global ischemia in isolated rat hearts and elucidate mechanisms underlying the effects of CQ.

METHODS

Isolated rat hearts were subjected to 30-min global ischemia, followed by 60-min reperfusion with Krebs-Henseleit buffer (KHB). Immediately before ischemia, 10 mL of pretreatment solutions (KHB, n = 4 or KHB + CQ [100 μM], n = 4) were injected through the aortic root. Cardiac function was examined based on the rate pressure product (RPP). Myocardial apoptosis was evaluated using TUNEL staining. To assess the reperfusion ischemia salvage kinase pathway, protein expression levels of AKT and extracellular signal-regulated kinase (ERK1/2) were determined using western blotting. To investigate the role of ERK1/2, an ERK1/2 selective inhibitor was used in eight additional rats.

RESULTS

The recovery rate of the RPP was higher in the KHB + CQ group than in the KHB group 60 min after I/R (KHB, 44 ± 3% vs. KHB + CQ, 69 ± 7%; P = 0.019, d = 2.2). CQ pretreatment reduced apoptosis and enhanced the phosphorylation of ERK1/2; however, AKT phosphorylation was unaltered. In addition, the ERK1/2 inhibitor abolished CQ-mediated cardioprotective effects.

CONCLUSIONS

CQ pretreatment showed protective effects on cardiac function after I/R by activating ERK1/2.