Antonio Cárdenas Cruz

Effects of Clofibrate on Salt Loading-Induced Hypertension in Rats

The effects of clofibrate on the hemodynamic and renal manifestations of increased saline intake were analyzed. Four groups of male Wistar rats were treated for five weeks: control, clofibrate (240 mg/kg/day), salt (2% via drinking water), and salt + clofibrate. Body weight, systolic blood pressure (SBP), and heart rate (HR) were recorded weekly. Finally, SBP, HR, and morphologic, metabolic, plasma, and renal variables were measured. Salt increased SBP, HR, urinary isoprostanes, NOx, ET, vasopressin and proteinuria and reduced plasma free T4 (FT4) and tissue FT4 and FT3 versus control rats. Clofibrate prevented the increase in SBP produced by salt administration, reduced the sodium balance, and further reduced plasma and tissue thyroid hormone levels. However, clofibrate did not modify the relative cardiac mass, NOx, urinary ET, and vasopressin of saline-loaded rats. In conclusion, chronic clofibrate administration prevented the blood pressure elevation of salt-loaded rats by decreasing sodium balance and reducing thyroid hormone levels.

Clofibrate prevents and reverses the hemodynamic manifestations of hyperthyroidism in rats.

BACKGROUND This study analyzed the effects of the chronic administration of clofibrate, a peroxisome proliferator-activated receptor-alpha (PPARalpha) agonist, on the development and established hemodynamic, morphologic, metabolic, and renal manifestations of hyperthyroidism in rats. METHODS The prevention study used four groups of male Wistar rats: control, clofibrate (240 mg/kg/day by gavage), T(4)(75 microg thyroxine/rat/day s.c.), and T(4)+clofibrate. All treatments were maintained for 3 weeks. Body weight (BW), tail systolic blood pressure (SBP), and heart rate (HR) were recorded weekly. Finally, temperature, SBP, pulse pressure (PP) and HR were recorded in conscious rats, and morphologic, metabolic, plasma, and renal variables were measured. The reversion study used two groups of rats, T(4)(treated for 6 weeks) and T(4)+clofibrate, measuring their hemodynamic variables and temperature for 3 weeks. RESULTS T(4) increased BP, HR, PP, and temperature when compared with control rats. Clofibrate prevented and reversed the increase in SBP, HR, PP, and temperature produced by T(4) administration, reduced plasma thyroid hormone levels, and increased plasma thyroid-stimulating hormone values and phenol-uridine diphosphate-glucuronosyl-transferase (UGT) activity. However, clofibrate did not modify the cardiac or renal hypertrophy, polyphagia, polydipsia, or proteinuria of hyperthyroid rats. In normal rats, clofibrate treatment did not significantly change thyroid hormone levels, phenol-UGT activity, or any hemodynamic, morphologic, or renal variables. CONCLUSIONS Chronic clofibrate treatment suppressed the hemodynamic manifestations and increased temperature of hyperthyroidism, an effect that can be produced by direct antithyroid effects. However, clofibrate administration did not modify the morphologic, metabolic, or renal alterations of hyperthyroid rats, indicating specificity in the antithyroid actions of clofibrate.

Dabigatran in Secondary Stroke Prevention: Clinical Experience with 106 Patients

Introduction. Our aim was to analyze our clinical experience with dabigatran etexilate in secondary stroke prevention. Methods. We retrospectively included patients starting dabigatran etexilate for secondary stroke prevention from March 2010 to December 2012. Efficacy and safety variables were registered. Results. 106 patients were included, median follow-up of 12 months (range 1–31). Fifty-six females (52.8%), mean age 76.4 (range 50–95, SD 9.8), median CHADS2 4 (range 2–6), CHA2DS2-VASc 5 (range 2–9), and HAS-BLED 2 (range 1–5). Indication for dabigatran etexilate was ischemic stroke in 101 patients and acute cerebral hemorrhage (CH) due to warfarin in 5 (4.7%). Dabigatran etexilate 110 mg bid was prescribed in 71 cases (67%) and 150 mg bid was prescribed in the remaining. Seventeen patients (16%) suffered 20 complications during follow-up. Ischemic complications (10) were 6 transient ischemic attacks (TIA), 3 ischemic strokes, and 1 acute coronary syndrome. Hemorrhagic complications (10) were CH (1), gastrointestinal bleeding (6), mild hematuria (2), and mild metrorrhagia (1), leading to dabigatran etexilate discontinuation in 3 patients. Patients with previous CH remained uneventful. Three patients died (pneumonia, congestive heart failure, and acute cholecystitis) and 9 were lost during follow-up. Conclusions. Dabigatran etexilate was safe and effective in secondary stroke prevention in clinical practice, including a small number of patients with previous history of CH.