Tacrolimus preserves vasomotor function and maintains vascular homeostasis.
J Heart Lung Transplant 2011;
30:583-8. [PMID:
21273094 DOI:
10.1016/j.healun.2010.11.022]
[Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2010] [Revised: 10/28/2010] [Accepted: 11/09/2010] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND
Post-transplant immunosuppression is associated with endothelial dysfunction that may lead to vasculopathy. We have previously demonstrated that cyclosporine causes vascular dysfunction. In this we study examined the effect of tacrolimus (Tac) in an identical model.
METHODS
Lewis rats (n = 8 per group) were injected with Tac (low, medium or high dose) or saline (Con) daily for 2 weeks. Segments of thoracic aorta (TAo) were assessed for endothelium-dependent (Edep) and -independent (Eind) vasorelaxation (E(max)) and sensitivity to endothelin (ET)-induced vasoconstriction (C(max)). ET(A) and ET(B) receptor (Rc) expression levels were determined in TAo. Tumor necrosis factor-alpha (TNF-α) and transforming growth factor-beta (TGF-β) expression were determined in myocardial (LV) tissue. Plasma ET levels and tissue oxidative injury were quantified by enzyme-linked immunoassay.
RESULTS
Tac did not impair Edep relaxation when compared with Con (p = 0.69). Impairment of sodium nitroprusside-mediated Eind vasorelaxation was noted with Tac (E(max): Con 69 ± 2%, Tac high 54 ± 2%; p = 0.0001), whereas no such impairment was seen with diltiazem-mediated Eind vasorelaxation (p = 0.06). Tac decreased sensitivity to ET (C(max): Con 222 ± 19%, Tac high 162 ± 11%; p = 0.0002) and ET levels (Con 0.8 ± 0.1 fmol/ml, Tac 0.4 ± 0.1 fmol/ml; p = 0.02). Tac did not alter ET(A) Rc expression (p = 0.28), but increased ET(B) Rc levels (p = 0.02). Oxidative injury was similar in both LV (p = 0.43) and Ao (p = 0.73) tissue. Similarly, TNF-α expression (p = 0.16) was not different between groups, whereas expression of TGF-β demonstrated a significant decrease with Tac treatment (p = 0.02).
CONCLUSION
Our findings suggests that tacrolimus has beneficial effects with respect to endothelial function.
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