Investigation of the effectiveness of levosimendan in the thromboangiitis obliterans (TAO) model formed with sodium laurate

Objective: Thromboangitis Obliterans, also known as Winiwarter-Buerger Syndrome or Buerger's Disease; It is a non-atherosclerotic disease with segmental, inflammatory involvement of medium and small sized arteries, veins and companion nerves, the formation mechanism of which has not been clearly revealed yet. In its pathophysiology, acute inflammation and thrombus formation in arteries and veins, which start with the immune process that is suggested to be triggered by tobacco use, are pathological findings. Anti-inflammatory, anticoagulants and some vasodilators are used in TAO treatment. Our study aims to observe the effect of calcium channel sensitizer Levosimendan (Simdax®, Daiichi Sankyo, Japan), which is a peripheral vasodilator, on the severity of the disease through the inflammatory and thrombotic pathways in the TAO model we will create, with biochemical and immunohistochemical data. There is no study in the literature in which the effects of Levosimendan on TAO through peripheral vasodilation mechanism are observed. If we obtain meaningful results from our study, Levosimendan, which has reached wide areas of cardiac use, can be considered as an alternative and new treatment for Buerger patients. Material and Methods: For the project, 24 male Wistar Albino rats with an average weight of 280-320 g were randomly divided into 4 groups. 1st group was sham-operated, 2nd group was the TAO group, 3rd group was the TAO+low dose Levosimendan (Simdax®, Daiichi Sankyo, Japan), 4th group was the TAO+high dose Levosimendan (Simdax®, Daiichi Sankyo, Japan). The femoral arteries of all rats were exposed using a surgical incision. The blood flow of the femoral artery was prevented by an arterial clamp placed proximal to the femoral artery. Then, 0.1 cc saline was injected into the 1st group and closed. All animals in groups 2, 3 and 4 were injected with 0.1 cc of Sodium Laurate-Saline solution adjusted at 10mg/cc to each animal. Arterial clamps were removed after 15 min. Rats in groups 3 and 4 were injected intraperitoneally with a low dose of Levosimendan(12 mcg/kg with 0.5% dextrose 10cc) and a high dose of Levosimendan(24 mcg/kg with 0.5% dextrose 10cc) at the 2nd hour following Sodium Laurate injection. For the next 7 days, Levosimendan administration (for the low-dose Levosimendan group and high-dose Levosimandan group) was continued with the same dose and administration method. The TAO formation was classified for all rats by daily observations for 1 week. After 1 week, all animals were again anesthetized to be sacrificed. MMP-3 (Matrix metalloproteinase-3), MMP-9 (Matrix metalloproteinase-9), Intracellular adhesion molecule-1 (ICAM-1), Vascular cell adhesion molecule-1 (VCAM-1) were examined by immunohistochemical examinations on femoral artery tissues. RAGE (receptor for advanced glycationend proudocts), ET1 (endothelin 1), TXB2 (thromboxane B2), 6K-PGF1-alpha (6-ketoprostoglandin F1-alpha), HMGB1 (high mobility group box protein 1) levels in plasma were measured by ELISA method biochemically. Results: In the serum sample of TAO induced rats, compared to control rats, RAGE was 51%; Endothelin-1 58%; Thromboxane B2 increased by 57%, whereas 6K-PGF1-alpha and HMGB1 levels did not change. When the serum samples of TAO+LD treatment group were compared with the rats in the control group, no change was detected in the levels of RAGE, Endothelin-1, Thromboxan B2, 6K-PGF1-alpha and HMGB1. Whereas; Compared to the TAO group; RAGE 43%; Endothelin-1 80%; There was a 57% decrease in thromboxane B2, but no change in 6K-PGF1-alpha and HMGB1 levels. While a significant increase was observed in Endothelin-1 levels in the TAO+HD treatment group compared to the rats in the control group, no change was found in the levels of RAGE, Thromboxan B2, 6K-PGF1-alpha and HMGB1. RAGE 57%; Thromboxane B2 decreased by 67%, whereas Endothelin 1, 6K-PGF1-alpha and HMGB1 levels did not change. We observed that the biochemical and morphological response of the low-dose treatment group to the treatment was better than the high-dose group, however, the response to the treatment was good in both treatment groups. In the observed immunohistochemical examinations in the TAO group, we observed the uptake of inflammatory markers MMP3, MMP9, ICAM and VCAM in the vessel wall. Conclusion: As a result; With the biochemical and immunohistochemical data we obtained and the morphological findings we observed, we showed that the efficacy of Levosimendan in the treatment of TAO is positive. Our work; We think that it provides positive data for the investigation of the efficacy of Levosimendan in the treatment of TAO and new studies to be organized for dose studies.