Na+/Ca2+ exchanger inhibitor restores endothelium-dependent relaxation in diabetic rat aorta

Blocking 5-HT2 receptor restores cardiovascular disorders in type 1 experimental diabetes

This study aimed to determine whether the serotonergic modulation, through selective 5-HT₂ receptor blockade, restores cardiovascular disturbances in type 1 diabetic rats. Diabetes was induced by alloxan (150 mg/kg, s.c.) and maintained for 4 weeks. 5-HT₂ receptor was blocked by sarpogrelate (30 mg/kg.day; 14 days; p.o.). Systolic blood pressure (SBP), heart rate (HR), glycaemia and body weight (BW) were monitored periodically. Animals were sacrificed at the end of the study and the heart, right kidney and thoracic aorta were removed; plasma samples were also obtained. Left ventricular hypertrophy index (LVH) and renal hypertrophy index (RH) were determined. Vascular function was studied in aorta rings; additionally, superoxide anion (O₂•⁻) production (by lucigenin-enhanced chemiluminescence) and lipid peroxidation (by thiobarbituric acid reactive substances assay) were measured. Neither alloxan nor sarpogrelate treatments altered HR, LVH or endothelium-independent relaxation. SBP, glycaemia, BW, RH, O₂•⁻ production and lipid peroxidation were significantly altered in diabetic animals compared with controls. Sarpogrelate treatment considerably decreased SBP, RH, O₂•⁻ production and lipid peroxidation. Endothelium-dependent relaxation was severely reduced in diabetic animal aortas compared to controls; sarpogrelate treatment markedly improved it. Our outcomes show that selectively blocking 5-HT₂ receptors has beneficial effects on impaired cardiovascular parameters in diabetes.