Simvastatin: pharmacological response in experimental hyperfibrinogenaemias.

UNLABELLED: Through a disorder in the endothelial haemostatic balance, hyperfibrinogenaemia could generate endothelial dysfunction. Statins would have antiinflammatory effects on injured endothelium. OBJECTIVE: Simvastatin pharmacological response in rats with hyperfibrinogenaemias induced by laparotomies was studied. METHODS AND RESULTS: Rats were subjected to multiple injuries (MI) for 30 days (1 laparotomy/week) and for 60 days (1 laparotomy/2 weeks). Simvastatin (0.035 mg/kg) was administered orally to the 30-day multiple injuries group after the third injury for a period of 10 days. A similar dose was administered to the 60-day multiple injuries group after the second injury for a period of 45 days. Blood samples of all the groups were obtained 72 hours after the last injury. In the 30 and 60-day multiple injuries groups, a statistically significant fibrinogen increase was observed (336.6 +/- 7.5 and 358.7 +/- 9.9, respectively) compared with the control group (207.0 +/- 3.0) (p < 0.001). There were no significant differences in the plasmatic fibrinogen (PF) levels between the control and simvastatin treated groups (224.9 +/- 1.4 and 216.3 +/- 4.3, respectively). There were significant differences between the 30 or 60-day MI untreated groups compared with the 30 or 60-day multiple injuries + simvastatin treated group (p < 0.001). Endothelial denudation and intima widening were observed in the untreated injured groups, whereas in the 60 day multiple injuries group + simvastatin, a regression of histopathological lesions was observed. CONCLUSIONS: The decrease of the inflammatory component that would accompany early atherogenesis processes and the regression of the histopathological lesions after treatment could be attributed to the decreased plasmatic fibrinogen.

Laser therapy on arthritis induced by urate crystals.

OBJECTIVE: We aimed to evaluate low-power laser therapy efficacy on fibrinogen (PF) in the plasma of rats with arthritis induced by urate crystals. In addition, anatomopathological (AP) studies were carried out. BACKGROUND DATA: Raised blood uric acid may form microscopic crystals in the joint. These crystals set up the inflammation called "acute gouty arthritis." METHODS: Two mg of uric acid were injected in both joints of the lower limbs of rats over 2 days. A group was treated with He-Ne laser (6 mW) on the injected joints during 3 consecutive days. After 96 h of the first injection, animals were sacrificed to determine fibrinogen by spectrophotometry. Sections from the lower limbs were used for AP studies. RESULTS: A statistically significant increase (p < 0.001) in plasma fibrinogen levels was observed in the group injected with urates, when compared to both control group and the laser-treated group. The AP observed in the untreated group showed an intense fibroblastic proliferation and chronic inflammation. In the group treated with laser no inflammatory reaction was observed. CONCLUSIONS: Laser therapy has an anti-inflammatory effect in arthropathy induced in rats injected with urates, determined by fibrinogen levels and by histological involution.

Hyperfibrinogenemia in rats treated with meloxicam.

Fibrinogen secretion is mediated by prostaglandin biosynthesis and is considered a risk factor for cardiovascular disease. Since meloxicam produces inhibition of prostaglandin biosynthesis it may help to normalize hyperfibrinogenemia. We investigated the pharmacological effect of meloxicam on fibrinogen levels and the possible regression of histopathological lesions of thoracic aorta. Rats were subjected to multiple injuries (MI) in the form of laparotomies (Lx) during a 30 day period (1/week). Meloxicam 0.065 mg/kg/day (per rat) was administered orally immediately after the third Lx in multiple injury animals during a ten day period. Blood was obtained 72 hours after the last injury in all groups. Fibrinogen was measured by spectrophotometry and the values were expressed in mg/dL. A statistically significant increment of fibrinogen was observed when comparing uninjured animals (control) (208.7+/-6.0) with the multiple injury group (336.6+/-7.5) (P<0.001). Fibrinogen decreased to the control value in the meloxicam group (198+/-8.7). Histopathological lesions were similar in the MI and meloxicam groups, showing endothelial denudation and intima enlargement from the thoracic aorta in 96% of the slices studied. The decrease in fibrinogen in the meloxicam group would be due to cyclooxygenase-2 (Cox-2) selective inhibition, even though the histopathological lesions did not regress.