Selective thrombolysis in acute deep vein thrombosis: evaluation of adjuvant therapy in vivo

The effect of iloprost and sildenafil, alone and in combination, on myocardial ischaemia and nitric oxide and irisin levels

Aim

Insufficient oxygen supply to organs and tissues due to reduced arterial or venous blood flow results in ischaemia, during which, although ATP production stops, AMP and adenosine continue to be produced from ATP. The fate of irisin, which causes the production of heat instead of ATP during ischaemia, is unknown. Iloprost and sildenafil are two pharmaceutical agents that mediate the resumption of reperfusion (blood supply) via vasodilatation during ischaemic conditions. Our study aimed to explore the effects of iloprost and sildenafil on irisin levels in the heart, liver and kidney tissues and whether these pharmaceutical agents had any impact on serum irisin and nitric oxide levels in rats with induced experimental myocardial ischaemia.

Methods

The study included adult male Sprague-Dawley rats aged 10 months and weighing between 250 and 280 g. The animals were randomly allocated to eight groups, with five rats in each group. The groups were: sham (control), iloprost (ILO), sildenafil (SIL), ILO + SIL, myocardial ischaemia (MI), MI + ILO, MI + SIL and MI + ILO + SIL. The treatment protocols were implemented before inducing ischaemia, which was done by occluding the left coronary artery with a plastic ligature for 30 minutes. Following the reperfusion procedure, all rats were sacrificed after 24 hours, and their heart, liver and kidney tissues and blood samples were collected for analyses. An immunohistochemical method was used to measure the change in irisin levels, the ELISA method to quantify blood irisin levels, and Griess’ assay to determine nitric oxide (NO) levels in the serum and tissue. Myocardial ischaemia was confirmed based on the results of Masson’s trichrome staining, as well as levels of troponin and creatine kinase MB.

Results

Irisin levels in biological tissue and serum dropped statistically significantly in the ischaemic group (MI), but were restored with ILO and SIL administration. Individual SIL administration was more potently restorative than individual ILO administration or the combined administration of the two agents. NO level, on the other hand, showed the opposite tendency, reaching the highest level in the MI group, and falling with the use of pharmaceutical agents.

Conclusions

Individual or combined administration of ILO and SIL reduced myocardial ischaemia and NO levels, and increased irisin levels. Elevated levels of irisin obtained by drug administration could possibly contribute to accelerated wound recovery by local heat production. Sildenafil was more effective than iloprost in eliminating ischaemia and may be the first choice in offsetting the effects of ischaemia in the future.

Dynamic change of coagulation and anticoagulation markers of patients with acute cerebral infarction during intravenous urokinase thrombolysis

BACKGROUND AND OBJECTIVE

The variations of blood coagulation and anticoagulation are of clinical importance in patients with acute cerebral infarction during intravenous urokinase (UK) thrombolysis. Although intravenous heparin is commonly used after thrombolytic therapy, few reports have addressed the relationship between the degree of anticoagulation and clinical outcomes, specifically the effect of thrombolytic agents on hemostasis. In this study, we dynamically monitored the activated partial thromboplastin time (APTT), the prothrombin time (PT), the thrombin time (TT) and the activated partial thromboplasmin time (APTT) in 56 patients with acute cerebral infarction during intravenous urokinase thrombolysis and analysed the relationship among the blood coagulation biomarkers (APTT, PT, TT, AT-III), as well as baseline patient characteristics and clinical outcomes. This allowed us to explore the valuable biomarkers for securing the thrombolysis regimen in clinical practice.

METHODS

The levels of PT, APTT, TT and AT-III in peripheral blood of 56 patients with acute cerebral infarction and 50 normal controls were assayed by ELISA. Dynamic transformation of these markers at the baseline and the time points of the first, second, fourth, eighth, 12th, 24th, 48th, 72nd and 96th hour after intravenous UK thrombolysis was monitored serially. The relationship between the levels of these biomarkers and the clinical effectiveness and safety of urokinase thrombolysis was evaluated.

RESULTS

The levels of PT, APTT, TT and AT-III in patients before intravenous UK thrombolysis were significantly lower than those in age- and sex-matched normal controls (all p<0.05). After treatment with UK, the levels of PT and APTT rose quickly during the first 4 hours (all p< 0.05), and then gradually recovered, reaching baseline at about the 48th hour. The activity of AT-III was slightly increased and showed fluctuations after UK infusion (p< 0.05), however the fluctuated range was not remarkable and lacked specificity.

CONCLUSIONS

Dynamic monitoring of PT, APTT and TT can indicate coagulative and anticoagulative functions of patients with acute cerebral infarction during intravenous urokinase thrombolysis. Monitoring of these markers can be helpful both in regulating the infusion speed and the dosage of UK, as well as increasing the efficacy and safety of UK therapy. However, assay for AT-III might be unnecessary.